Tropical Tidbits from the Tundra

Nicole floods North Carolina; More mischief is possible late next week

By: Levi32, 4:30 PM GMT on September 30, 2010

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Heavy rains preceding Nicole have flooded North Carolina with historic rains, and more is on the way as the low pressure center that was Nicole will be coming onshore later today. The NHC has taken away her name, but tropical weather is still threatening lives and property in the eastern US today. Rain and wind will continue to bash the eastern seaboard for the next 24-36 hours.

Looking onward, more mischief is in store for the Caribbean, but this time from the east for a change. Nicole will leave lingering low pressure behind in the western Caribbean, and a large area of low pressure in the central Atlantic will be propagating westward into the SW Atlantic Basin next week. This will probably try to develop something in the Caribbean or near the Caribbean islands, and with the pattern still favorable for activity in this area of the world, it will be something to watch for.

There is a model war going on between the ECMWF and the GFS with the projected longwave pattern over North America in 7-10 days. The ECMWF has a persistent trough remain behind after Nicole's trough leaves, while the GFS is more progressive and pumps the ridge over the top of the eastern US, similar to the setup before Matthew and Nicole. Given the same general pattern in the north Pacific, the GFS may make more sense here for once, but we will have to see. The danger is that the tropical cyclone develops far enough south to sneak under a building ridge over the top and comes far enough west to recurve into the SE US on its way out. Even if not so, the Caribbean islands should certainly be watching this for potential mischief on its way west. Again, the pattern favors activity in the Caribbean during October and such activity can easily threaten land, including the United States.

We shall see what happens!

Tropical Storm Nicole Visible/IR2 Satellite (click image for loop):



Invest 97L Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






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Nicole bringing flooding rains to North Carolina

By: Levi32, 4:43 PM GMT on September 29, 2010

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Tropical Storm Nicole continues to be the main feature in the Atlantic today. Her center is near the northern coast of Cuba, and is now leaving the area of purely tropical forcing that is still over the NW Caribbean. She is now entering the zone of baroclinic forcing that is sitting off the SE US coast, and this is why the low pressure envelope associated with the storm is elongated south to north. Nicole's center will be jumping northward rather quickly after she leaves Cuba, and will likely reach North Carolina in 24 hours or so where it will make landfall.

The biggest story with this storm will be rainfall, as there is not a whole lot of wind involved, although the Carolinas will have to watch out for trees getting blown over in the kind of gusts they could be seeing out of this. North Carolina is getting drenched with rain once again, with 3+ inches falling in some areas during the last 24 hours, and that's on top of everything that has already fallen in that area during the past week. Flooding is likely to be a major problem here, and as was mentioned yesterday, North Carolina will be hit harder than Florida with this storm.

Elsewhere....after Nicole leaves she will likely leave lingering low pressure in the Caribbean that will entrain the remnant circulation of Matthew in a few days, and two tropical waves out in the central Atlantic will try to get drawn into the SW Atlantic Basin action during the next week attempting to cause mischief. The season will start winding down now in the sense that we won't have a named storm on the map every single day, but that doesn't mean it's over. I still think we're in for 4 more storms or so. We have all of October left to get through, and the United States does get hurricane landfalls during that month. Even November will likely see some action in the Caribbean, and even then the U.S. has to watch for storms like Ida from last year that come up, and even though they lose their tropical characteristics, they're still a huge deal compared with your average fall storm.

We shall see what happens!

Tropical Storm Nicole Visible/IR2 Satellite (click image for loop):



Tropical Storm Nicole Doppler Radar:



Tropical Storm Nicole Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






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Nicole to bash Florida and the Carolinas; Pattern remains active into October

By: Levi32, 4:43 PM GMT on September 28, 2010

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TD #16 has formed in the northwest Caribbean, and will be named Nicole very shortly. The circulation is very broad and thus development will be gradual, and as this gets drawn north into south Florida in 24-36 hours it will likely be a moderate tropical storm. Due to a strong trough diving into the SE US, the storm will be lopsided in Florida with most of the bad weather to the east of the center, with the folks to the west getting very little. The storm will be moving up the front into the Carolinas shortly after leaving Florida, and it will likely be a bigger storm there than in Florida. Baroclinic forcing due to the trough and the front will probably make the system asymmetric and the NHC will probably try to strip Nicole of her name, arguing that she's extratropical. This is all fine....but people will have to be aware that they are not getting a normal late September frontal wave, but a tropical system. It really should have its name as long as it is a distinct entity bringing tropical conditions to the coast.

The key to how bad this gets will be the next 24 hours to see how tight and how deep the storm can get before crossing Cuba. A pressure of 995mb or lower by that time would help keep the system together as it moves up the front, as opposed to getting strung out as baroclinic forcing lowers pressures in the path of the storm. A system holding itself together will be more able too utilize the baroclinic support to deepen and become stronger in the Carolinas. The 06z GFDL illustrated this by bringing a 975mb Cat 1 hurricane into the Carolinas. This is not likely but is certainly possible if Nicole gets off to a very good start before being drawn north.

Overall, this is not a particularly bad situation, but folks should be aware that this will be a potent little storm riding up the eastern seaboard, and hurricane force gusts are not out of the question in the Carolinas, along with heavy rains.

Beyond Nicole we will likely see more low pressure try to gradually organize in the Caribbean as soon as she leaves. The monsoon trough isn't going away and what's left of Matthew's old circulation may try to rotate out over the east Pacific and back across into the western Caribbean. The pattern will remain favorable for lots of tropical activity in the Caribbean throughout most of October, and if we can get one of these lows to sit long enough to develop into a hurricane before getting drawn north, we will have a big problem for the U.S. coastline. I can't say for sure whether we will get a big storm threatening the coast or just a bunch of little ones, but I can tell you the pattern favors storm activity south of the United States for the end of the season and with the troughs trying to draw that activity north, people should be on the lookout for trouble.

We shall see what happens!

Tropical Depression #16 Visible/IR2 Satellite (click image for loop):



Tropical Depression #16 Doppler Radar:



Tropical Depression #16 Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 4:45 PM GMT on September 28, 2010

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Nicole to develop and bash the SE US this week, but not too strong

By: Levi32, 4:14 PM GMT on September 27, 2010

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Please forgive my voice and articulation in the video today. I am very tired.

In the Atlantic today the action continues to be focused in the Caribbean. What's left of Matthew's circulation is weakening over Mexico and still causing flooding problems, but one can see how the heat immediately shifted eastward back into the western Caribbean after Matthew died. We now have lowering pressures down under 1005mb in the western Caribbean and what looks to be a weak low-mid level circulation starting to develop east of Cozumel. Over the next 24-48 hours this will be gradually organizing, but rapid development is unlikely due to the massive area of heat that has to be focused, and as with all monsoonal systems, this will need time to become very strong. Fortunately it doesn't have a lot of time as a trough diving into the SE US will be drawing this north into Florida within the next 48-72 hours.

Along with the system not having very much time to develop, the same trough drawing it north will be punching dry air into the Gulf of Mexico from the northwest, and this will likely keep the western side of the storm dry with most of the activity weighted to the east of the center, as is typical of many early and late season systems due to trough interaction. My feel is that this will be a tropical storm in Florida, and then it is likely to get drawn NNE for a second hit on the Carolinas a day or so later. A storm of this type and of this track means SE Florida and North Carolina will get the worst bashing, and it may very well be North Carolina that gets the nastier end of the storm as it will have had the most time to strengthen by that point. By the time it gets to the Carolinas it may have the look of a hybrid storm due to intense interaction with the trough, but that won't necessarily mean that it is one.

Overall, Nicole should develop and lend out a double bashing to the SE US coast, but probably not as a hurricane. However, caution is still advised as there is a lot of energy available here, and if the storm tries to bundle it at the last minute we could see some potent deepening and some nasty winds. You can see how this idea is starting to take shape that during the final days of September a tropical cyclone would threaten the SE US.

This pattern will not be letting up after Nicole, and yet again a piece left behind may be the catalyst for another storm to develop in the western Caribbean after Nicole is gone. The pattern is such that as the trough lifts out, high pressure builds in over the eastern US to help incubate low pressure in the Caribbean which starts the whole process over again. This should be the story throughout most of October, and the SE US and all the land areas of the SW Atlantic Basin should be wary of more storms developing in close to home before the season is over, and if one of them can bring in all of the available energy, it will likely result in a major hurricane, and that possibility is one that should be watched for.

We shall see what happens!


Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 4:16 PM GMT on September 27, 2010

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Matthew dying; Re-development under the guise of "Nicole" to threaten the GOM

By: Levi32, 5:38 PM GMT on September 25, 2010

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Matthew continues to be the big story today as he is producing massive amounts of rainfall and flooding across central America. The system is now decoupled with the mid-level center heading westward while the surface center is over the Gulf of Honduras but about to move inland over Belize. This will likely die inland as the shortwave coming into the central US has not dug in enough to tug this north yet.

One can see the arc of clouds extending east of Matthew out towards the tip of Honduras and Nicaragua as the monsoonal jet continue to come into Nicaragua. This extended envelope of low pressure is likely where we will see the reformation of a surface low during the next several days that will probably be named Nicole, though it will be odd considering she will be within the same monsoonal circulation as Matthew.

This reformed system will then get drawn north by the upper trough towards Cuba and Florida, and again the track cannot be nailed down until we see where the storm forms, but the general idea remains that the gulf coast from New Orleans eastward is the main threat zone with this. Intensity is also something that will have to be worked out later, but moderating factors in the Gulf of Mexico will likely be wind shear and dry air. The farther east the storm tracks, the better off it will likely be. We could be seeing just a moderate tropical storm or a potent hurricane, depending on how things shape up.

The 6z run of the GFS was concerning for many as it turned the storm westward across the northern gulf towards Texas and Mexico. The reason for this is that the model brought the storm up so late that the trough lifted out and the ridge built back in over the top and directed the storm westward underneath. Given that we now likely have to deal with a 2nd development after Matthew and the time line is being shifted later, it is entirely possible that this kind of situation could happen, but I still feel that the eastern gulf is the most threatened from this. However, as I have said, the western gulf shouldn't let their guard down because all it takes is a few days where one of these troughs lifts out, the ridge builds back in, and if you have a storm coming up then it could aim for the western gulf, even though the pattern is more favorable for eastern gulf landfalls.

Beyond Matthew and/or Nicole we will likely see another system try to spin up in the Caribbean quickly after the first storm moves out, and again the pattern will favor high activity in the SW Atlantic Basin throughout most of October, and such activity will almost always threaten land, including the United States. Hopefully we get lucky and sneak away without a big hit, but chances are one of these storms will be a major one and somebody will get smacked before the season is over.

We shall see what happens!

Tropical Storm Matthew Visible/IR2 Satellite (click image for loop):



Tropical Storm Matthew Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






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Matthew; Nicole or not? U.S. to be threatened next week regardless

By: Levi32, 5:10 PM GMT on September 24, 2010

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems or questions about the video.



The big story today is Tropical Storm Matthew which has developed in the western Caribbean and is now of moderate intensity with a pressure of 998mb. The storm is moving quickly WNW towards the Nicaragua/Honduras coastline, and will likely move ashore there later today.

In the video I go into detail about the two main scenarios that could happen here. The NHC now thinks Matthew will die over central America and take a track that keeps it over land for so long that it won't be able to recover even if it is drawn north. If this happens, we would just get a new storm named Nicole to come up behind it, likely developing within the envelope of low pressure extending to the east of Matthew. This would be very possible and as I mentioned yesterday with monsoonal systems like this it would not be surprising at all to see reformation of low pressure back over the water if this moves inland and weakens sufficiently.

The other scenario is the one that was painted yesterday, where Matthew doesn't track quite as far south, maintains some strength over the Gulf of Honduras waters east of Belize, perhaps moves inland a tad, but then starts getting drawn northeast as a trough dives into the eastern US and starts tugging on it. If the storm were to stay over the water just east of the Yucatan, it would strengthen and become a problem for the eastern Gulf of Mexico.

I am not quite ready to make a definite call on this, as there are a lot of variables in play that simply cannot be defined yet. However, what I am confident in is that the SE US is going to get threatened by a storm within the next week to 10 days, no matter how it happens. It could be Matthew, but then it could be Nicole. It doesn't matter. The reason Nicole would form is because Matthew dying would free up the heat to go somewhere else and bundle, and it does have to bundle, because there is too much of it built up in the Caribbean and it has to be released. The atmosphere will find a way to do that, probably in the form of a tropical cyclone, and then find a way to draw it north to get the heat out of there. Nobody should let their guard down just because Matthew may be moving inland. Something will be coming out of the Caribbean next week.

And it doesn't end there. Matthew or Nicole, will not be the last storms to deal with in the SW Atlantic Basin. This area is primed for activity, and the ensembles continue to support my idea that October will continue to be a dangerous month by showing very low pressures in the Caribbean through the next two weeks. This is the pattern that can threaten the United States several times in a row, as well as the Caribbean countries and islands.

No matter what happens, our first concern today is Central America which may be getting lethal amounts of rain from Matthew, no matter which path he decides to take.

We shall see what happens!

Tropical Storm Matthew Visible/IR2 Satellite (click image for loop):



Tropical Storm Matthew Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






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95L developing; Dangerous times to continue through Oct. for the U.S. and Caribbean

By: Levi32, 4:24 PM GMT on September 23, 2010

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North of 20N the Atlantic is actually quiet for once. We do have the ghost of Julia, but there are no big Cape Verde hurricanes out there today. This means that the Caribbean is now finally allowed to light up, and sure enough if we look down there we see Invest 95L gradually developing as it cruises westward north of Columbia this morning. As I was recording the video the recon had just gotten in there and had only found very light WSW winds with no real defined center, but as of this writing they have sent out a vortex message with a fairly well-defined center of circulation, and we will have to see if this is enough for the NHC to upgrade this to TD #15.

95L will be moving towards the Nicaraguan and Honduras coasts over the next couple days, and will likely try to turn north into the Gulf of Honduras east of Belize. This turn will be slow and lethargic as the break in the ridge to the north of the system develops, and thus the countries of Nicaragua, Honduras, Guatemala, and Mexico will have to be aware of potentially excessive rainfall from this system as it takes its time getting out of the western Caribbean.

Due to land interaction the system will likely remain fairly weak as it negotiates with Nicaragua and Honduras, but if it gets out over the water east of the Yucatan it should quickly try to strengthen, utilizing the very high ocean heat potential in that area. If the system stays over land longer this could disrupt the circulation and result in a broader, weaker system getting drawn northward, and this is what the ECMWF showed on last night's run. I like the general idea of a track over a portion of Nicaragua/Honduras, and then up just east of the Yucatan in a NNE direction towards the Yucatan Straights and on into the eastern Gulf of Mexico.

It is still too early to really nail down the track so there are a variety of things that could still happen, but the general message remains that there should be a storm getting named Matthew approaching central America and then eventually getting drawn north towards the eastern Gulf of Mexico and threatening those areas along that general path. Land interaction with central America will be the main determining factor of intensity in the Caribbean, and in the Gulf of Mexico the moderating factor will likely become dry air from the west. There is potential for this to be a rather strong hurricane if it stays over the water in the Caribbean for most of the time, as the 0z GFDL and 0z NOGAPS showed last night.

Elsewhere....the ghost of Julia and the struggling Lisa out in the eastern Atlantic will continue to meander around as sisters, and neither is much of a threat to anyone.

The dangers for the Caribbean and United States will not go away with Matthew, as the pattern will remain loaded for action in the SW Atlantic Basin throughout most of October. I expect we will see multiple threats to our coastline before the season is out. The end-game here is one that will likely threaten and hit land with every punch.

We shall see what happens!
Tropical Storm Matthew Visible/IR2 Satellite (click image for loop):



Tropical Storm Matthew Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 5:09 PM GMT on September 24, 2010

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95L a big danger to the western Caribbean and southeast U.S. next week

By: Levi32, 4:36 PM GMT on September 22, 2010

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Things are starting to heat up in the Caribbean as 95L gets better organized north of Venezuela and Columbia. Radar out of Curacao shows a well-defined rotation associated with the low pressure area, and although convection is still widely scattered, I expect this system will continue to gradually organize and develop, probably getting named Matthew by the time it reaches central America in a couple days.

Problems with the forecast will arise right away as a lot will depend on how deep 95L penetrates into central America before getting drawn slowly northward by a trough over the eastern US. A deep penetration with the storm meandering over land for a couple days before getting into the Gulf of Mexico would result in a weaker and larger storm impacting the SE US, but a track that stays more over the warm NW Caribbean waters could result in a potentially major hurricane near Cuba and Florida.

The video shows comparisons to 1964's Isbell, and in an unintentional coincidence Joe Bastardi over at Accuweather threw up some of the same maps on his video right before I recorded mine, so if you see them over there, you're going to see them again here, and I apologize for that. However, the important message is also the same, that this kind of pattern can result in a potent storm affecting the SE US, and folks should be ready for this if it becomes a nasty situation.

Overall, the first concern with future Matthew will be heavy rains in central America in case this moves inland and stalls over land before moving northward, and then worry will shift northeast to Cuba and the eastern Gulf of Mexico. Details on the track will be worked out as we go along, as we could still see a track try to sneak over or up just east of Florida, but I still think getting into the eastern Gulf of Mexico is a good bet. Intensity will largely depend on how Matthew interacts with central America before coming northward.

The trouble does not end with this storm either. The pattern still supports mischief in the SW Atlantic Basin throughout much of October, and this coming month is likely to be the most dangerous one this season for the United States and Caribbean countries. This has been setup by a number of factors which are coming together now to produce the end-game for this season. I will continue to voice the concern about this as the SW Atlantic Basin lights up. We've already had to deal with Karl and now Matthew is coming on the scene. Let's not get caught sleeping.

We shall see what happens!

Invest 95L Visible/IR2 Satellite (click image for loop):



Invest 95L Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 5:44 PM GMT on September 22, 2010

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Next week to be very dangerous for the U.S. coast from the central GOM eastward

By: Levi32, 4:16 PM GMT on September 21, 2010

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We are setting up for a big threat to the U.S. coastline next week that has a high chance of being the first direct hurricane landfall of the season on our shores. As expected, the Caribbean is lighting up with convection today as Igor has left the scene, and the tropical wave in the eastern Caribbean has been declared Invest 95L. This system will be skirting north of the coast of South America and try to gradually develop. Once it gets north of Panama we could see it try to get named, and the countries of Nicaragua and Honduras will need to keep a close eye on this.

After 95L makes a run at central America it will entrain the monsoonal trough and get draw northward into the northwest Caribbean and eventually into the eastern Gulf of Mexico. The reason for this is that the amount of heat being bundled into this system is going to be massive, and the atmosphere needs to get rid of it. To do this, it will send a trough down to get the storm and draw it out of the tropics. The corridor for this will be from the central gulf eastward, meaning that the western gulf will likely be spared, although they shouldn't let their guard down until we actually have a storm.

We have been discussing this situation for quite some time now and there's nothing new here. We knew this was coming and hopefully everyone's prepared. It is still too early to speculate on how strong the storm will be or what the exact track will be, but we know a storm is coming and will threaten the U.S. coastline, as well as several Caribbean countries, by the time next week rolls around.

Elsewhere....Lisa finally got named and is a storm that is doomed to struggle with dry air her entire life. We'll see if this ever becomes a hurricane, but she will be around for a while meandering in the eastern Atlantic, eventually heading out to sea. The same pattern that will produce Matthew in the Caribbean isn't just going away after one storm, and we will likely see multiple threats get drawn out of the SW Atlantic Basin during the month of October.

We shall see what happens!

Invest 95L Visible/IR2 Satellite (click image for loop):



Invest 95L Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






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Big trouble looming next week in the Caribbean, likely to threaten the U.S.

By: Levi32, 4:47 PM GMT on September 20, 2010

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems or questions about the video.



Igor is now leaving the scene, and was not as bad of a storm as it could have been for Bermuda. The storm got too large for its own good and the Atlantic Ocean just cannot support a storm like that. Regardless, he was a monster and a big deal there, but they were well-prepared in Bermuda and as far as I've heard there has been no loss of life, for which we are very grateful.

Invest 94L west of the Cape Verde Islands should be a depression, but since it's way out there the NHC will just play that game with it until it gets more convection or whatever they want out of it. At any rate, this system will likely stay weak and may be one that does not become a hurricane, and will likely end up going out to sea eventually, but taking its time to do so.

The big story is going to be the Caribbean firing up during the final week of the month. We can already see convection increasing in the central and eastern Caribbean as Igor exits the scene to the north. This is a perfect illustration of the theory I've been talking about where big Cape Verde storms cause subsidence to their south and southwest in the Caribbean, but when they pull out you get a renewed burst of easterly trades that causes convergence and convection to go off. To think about it in a larger scale, when the Cape Verde season starts to shut down for the year in October, the Caribbean will finally be able to light up, and this is the kind of pattern we're heading towards now as Igor is likely Africa's last big hurrah, and although we may eek out a couple more Cape Verde-type storms, Igor is probably the last real big one.

The models are all onboard now with low pressure developing in the western Caribbean next week, and it will likely get drawn north somewhere. The pattern is currently hinting that New Orleans and eastward should be concerned due to the weakness in the eastern part of the US, but the western gulf shouldn't let their guard down either. We'll have to get this forming to nail down the details. The point is that the pattern is rushing to draw heat out of the area that hasn't gotten rid of it yet this year, the Caribbean. Thus, the United States, Cuba, Mexico, and the Bahamas should be watching for a threat from the south sometime next week.

We shall see what happens!

Hurricane Igor Visible/IR2 Satellite (click image for loop):



Hurricane Igor Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






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Igor bears down on Bermuda; Mischief to threaten the SW Atlantic Basin in 10-15 days

By: Levi32, 5:18 PM GMT on September 18, 2010

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems or questions about the video.



Igor continues to churn away in the central Atlantic. His outer bands will begin affecting Bermuda in a few hours, and this will be the beginning of an onslaught that will last for a painfully long time. This may be one of the worst hurricanes Bermuda has ever had to face. Igor is massive and the wind field is one of the largest I have seen. On satellite imagery you can see him pulling southwest winds off of Venezuela, over 1000 miles to the south, indicating an insanely large circulatory influence. In fact, the only reason Igor is down to a Cat 2 is because he is too large for his own good. The Atlantic was not built to support mega-hurricanes. It simply doesn't have the heat content necessary to sustain a storm of this size. The only place that can pull it off is the Caribbean, and it is hard to get a storm this big in there. However, with a pressure still down at 945mb, Igor is extremely powerful, and we will be praying for Bermuda as they face this monster.

Karl died very quickly over Mexico, and I explain in the video why he was rapidly weakening before landfall. The NHC said this was "FOR REASONS THAT ARE
NOT READILY APPARENT". That's bologna....it was always obvious why Karl would likely not be able to reach his full potential at landfall, and nothing about it came as a surprise to me personally. That's why I had him capped at Cat 2, and although he did briefly make it to Cat 3, conditions aloft halted him and turned things around rather quickly.

Another interesting thing that I mentioned in the blog yesterday is the envelope of low pressure that extended to the north of Karl that has been producing a lot of heavy convection, and I mentioned that this might try to form a potent little low that would move ashore into south Texas. This morning indeed you can see the rotation on satellite and radar north of Brownsville, and lots of heavy rain will be impacting the Texas coast over the next couple days.

More models are jumping onboard the bandwagon of getting a storm to form in the Caribbean before the month is out. I have been voicing concerns about this for a long time now as the Cape Verde season starts to wind down, allowing the SW Atlantic Basin to open up, and I think we're going to be seeing a threat to the Gulf of Mexico that starts to develop during the final days of September. There will likely be more than follow during October, and the pattern is such that I would be very concerned about multiple landfalls on the U.S. coast, as well as potential for the Caribbean countries to be impacted.

We shall see what happens!

Hurricane Igor Visible/IR2 Satellite (click image for loop):



Hurricane Igor Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 5:20 PM GMT on September 18, 2010

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Mexico gets slammed, Bermuda is next; Dangerous pattern ahead for SW Atlantic Basin

By: Levi32, 5:01 PM GMT on September 17, 2010

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems or questions about the video.



We are now up to 5 major hurricanes this season, and two of them are churning simultaneously right now in the Atlantic, along with a 3rd hurricane that is only a Cat 1. Karl is making landfall right now near Veracruz, Mexico as a powerful little storm that steadily intensified through this morning, becoming a Cat 3. The limits that I thought would come into play to keep Karl capped at Cat 2 didn't stop him until he made Cat 3, but as soon as he hit Cat 3 those limits did come in and have started weakening him considerably. At one point the recon recorded a 10mb rise in just 90 minutes. Part of this is due to proximity to land, but a lot of it has to do with the limiting factors in the upper-level environment around the storm. The most favorable place for Karl is off to the northeast where the greatest ventilation is, but where he's at right now there are limitations to the northwest of the storm and outflow isn't that great anywhere except the equatorial channel. If Karl had come in farther north and been 300-400 miles northeast of where he currently is he would be a monster. That's why you see all the thunderstorms going off southeast of Texas. This was another close call for the United States.

Igor will likely be passing close to Bermuda and bringing devastation to the island. Hopefully everyone there is prepared for an onslaught. Igor is massive and will bring hurricane conditions to the island for many hours. There is still some hope that this tries to pass farther to the west of them but it's looking like it will go ahead and follow the majority of the models right close to Bermuda on its way out.

The pattern over the next 15 days is still looking to evolve towards an end-game for September that may entail a hurricane threatening the Gulf of Mexico. On the video today I show many of the ensembles that are hinting at this in the overall pattern, and why we should be concerned about the next 30-40 days where the United States will likely get threatened with more than one storm. To see things evolve this way, if they go as I think they will, is incredible. It is amazing to see these things during a major seasonal transition from summer to winter where the pattern changes and gets defined a different way, making the forecasts different and the consequences different. It's a work of art, really, and what's being sculpted is something that will likely threaten the SW Atlantic Basin with mischief before this month is over.

We shall see what happens!

Hurricane Karl Visible/IR2 Satellite (click image for loop):



Hurricane Karl Track Models:



Hurricane Igor Visible/IR2 Satellite (click image for loop):



Hurricane Igor Track Models:



Hurricane Julia Visible/IR2 Satellite (click image for loop):



Hurricane Julia Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






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Bermuda and Mexico face hurricane hits; United States may be next

By: Levi32, 4:44 PM GMT on September 16, 2010

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems or questions about the video.



We have 3 hurricanes simultaneously in the Atlantic, an incredible feat. Karl is a hurricane, as he has an eye, and the recon has found flight-level winds of 75kts and a pressure of 983mb. This will likely become a strong Cat 1 possibly pushing Cat 2 at landfall. At this time I don't see Karl becoming a major hurricane, but he will likely be steadily intensifying up until landfall.

Igor is still a big deal out in the central Atlantic, and poor Bermuda is bracing for one of the worst kinds of storms they can get, one that recurves very close to the island but slowly. Igor will find a way to escape, but with no trough digging deep in to get him, he will only be sneaking through the weakness in the ridge at a slow pace, likely taking his time getting by Bermuda. I still hold out some hope that he hangs back longer and makes a run towards 70W before recurving fully, an option that would spare Bermuda the eye, but either way they are still going to get hurricane-force winds for a long period of time, and although the storm will be weakening, this is still likely to be very bad for them.

Julia is a Cat 1, not a Cat 2, and will be weakening as she heads northwest and out to sea.

The video today again touches the topic of the SW Atlantic Basin firing up as we head towards the end of September and into October, which may end up being the most dangerous month for the U.S. yet this year. The GFS is voicing this loudly now from the rooftops as nearly every operational run and ensemble mean shows a hurricane threatening the Gulf of Mexico in 10-15 days. This is a real possibility that I will be watching for, as the pattern supports this type of thing. In the video I give some examples from our analog years that had active Cape Verde seasons, which resulted in an inactive Caribbean until the end when some big storms came to life. It is intriguing how the Meteorology works in that kind of a situation.

It will soon be time to start looking towards not the east, but the south, for gathering dark clouds.

We shall see what happens!

Tropical Storm Karl Visible/IR2 Satellite (click image for loop):



Tropical Storm Karl Track Models:



Hurricane Igor Visible/IR2 Satellite (click image for loop):



Hurricane Igor Track Models:



Hurricane Julia Visible/IR2 Satellite (click image for loop):



Hurricane Julia Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






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Bermuda stares down Igor; Potential threat to the U.S. during final days of September

By: Levi32, 4:50 PM GMT on September 15, 2010

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems or questions about the video.



Atlantic ACE is soaring through the roof today. We have 3 storms in progress, and 2 of them are Cat 4 hurricanes, Igor and Julia. This is only the 2nd time in history that the Atlantic has had two Cat 4 hurricanes going simultaneously. Tropical Storm Karl is inland over the Yucatan and nearly made it to a hurricane before landfall. Radar out of Belize showed a well-defined eye wall at landfall. Karl will pop out the other wide in the Bay of Campeche and likely strengthen into a hurricane before making landfall in Mexico a 2nd time.

Igor is weaker than yesterday but still the biggest fish in the sea, and although he is likely to stay out to sea, the island of Bermuda may get smacked badly by him. They should be preparing for a major hurricane right now. The model consensus currently has Igor going right over Bermuda but I still think there's a chance he comes farther west and makes a run at 70W before recurving out. The Canadian and NAEFS Ensembles are a little disturbing this morning as both of them show half of their ensemble members getting Igor to miss the trough and get stuck beneath the building ridge by Day 8. This is a scenario to continue watching warily for, as the models have been consistently having to correct southwest during the course of Igor's lifetime, and if those errors continue then we will have to watch for him hanging back longer and getting farther west. For now though, Bermuda needs to be preparing for a direct hit.

The SW Atlantic Basin is already coming to life with Karl, and will likely be hosting another storm in about a week's time as something is likely to try to come up out of the ITCZ and enter the Caribbean next week. The GFS has been all over this, and the pattern favors a storm sitting south of the United States during the final days of September as troughing develops in the Gulf of Alaska, pumping the ridge to the east. This I think is the start of my theory that October is going to be the most dangerous month for the U.S., in that when the Cape Verde season shuts down for the year, the focus of upward motion will still be in the Atlantic, which means the activity won't go away, but will simply shift west into the SW Atlantic Basin. If the breeding zone shifts west, tracks shift west as well, and deeper troughs as we move through Autumn will be able to pick up Caribbean storms and bring them up towards the gulf coast.

We shall see what happens!

Tropical Storm Karl Visible/IR2 Satellite (click image for loop):



Tropical Storm Karl Track Models:



Hurricane Igor Visible/IR2 Satellite (click image for loop):



Hurricane Igor Track Models:



Hurricane Julia Visible/IR2 Satellite (click image for loop):



Hurricane Julia Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 4:56 PM GMT on September 15, 2010

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Igor to threaten Bermuda; Could October be the most dangerous month for the U.S.?

By: Levi32, 4:26 PM GMT on September 14, 2010

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems or questions about the video.



You can really tell that it's mid-September out in the Atlantic today. We are about to have 3 storms in progress simultaneously by the time today is out. Invest 92L in the western Caribbean is probably a tropical depression now and the NHC will likely classify it later this afternoon or evening. This won't have time to strengthen very much before hitting the Yucatan, but once it pops out the other side it will likely resume intensification into at least a strong tropical storm or minimal hurricane in the Bay of Campeche, named Karl. While south Texas should still keep an eye on this, Mexico is most likely to get the hit now that Igor has started gaining latitude. The consequences of that involve the big Texan ridge getting more support from the overall pattern, which ends up blocking Karl from moving up into Texas.

Speaking of Igor, after cloud tops in the core ring warmed considerably last night, they have rebuilt this morning and the hurricane is strengthening again. Igor may make another attempt at Cat 5 today and tonight. He got darn close yesterday morning. I believe he was borderline. Igor is now finally moving WNW after defying the models thus far, and now finally the models will have good scores for the next couple days. I still think the long-term track needs to be adjusted west, namely west of Bermuda, and the storm could still make a run at 70W before recurving out. The NAEFS ensembles, which I show on the video today, illustrate why the pattern could still support Igor hanging back and being slower to move out than the rest of the models think. Support for this is lower now, but the possibility is still there. However, I think the US is pretty safe now, and this should be a threat to only Bermuda, which may be facing down a very potent hurricane in a few days. Our friends over there should be preparing well for this. Igor is likely to be starting to weaken by the time he gets close to Bermuda, but he will still be a very formidable storm.

Hurricane Julia is also churning in the eastern Atlantic, and this storm will also go out to sea without threatening the United States.

The pattern changes though as we head towards the end of September and into the month of October. As the Cape Verde season shuts down, the Atlantic will still be primed for activity as global heat in the tropics will still be focused in our basin, and that means our season will keep going, but farther west. I have been voicing concern for a while now about the SW Atlantic Basin lighting up by the end of September, and the pattern is looking to be setting up for that. The GFS is now catching on with its runs during the last couple days, all showing one or two storms in the Caribbean and SW Atlantic in 10-15 days. With all the other ensemble suites now showing very low pressures and high precipitation in the SW Atlantic Basin in two weeks, there is reason to be concerned that this pattern could produce a hurricane threat to land, including the United States, during the final week of September.

Beyond that though, October may end up being the most dangerous for the US once we total up all the landfalls and impact storms at the end of the year. With the activity shifting west, the tracks shift west as well, and in the video today I show how the KMA supports the idea that the pattern will remain very conducive for an active tropics south of the United States during October, with tracks that could easily recurve up and threaten our shores.

I am confident that we are going to hit our quota of 18 named storms that I forecasted for this season. There were doubts through most of August when things were still rather quiet, but look what has happened so far. We are up to 10 soon to have 11, and it's not going to be that hard to rack up 7 more. Now we will also test my forecast of 6 U.S. landfall impacts. We've only had one real landfall so far (Bonnie). If we count impacts then we have had 4, Alex, Bonnie, Earl, and Hermine. I think more are likely to come, so keep your eyes open.

We shall see what happens!

Invest 92L Visible/IR2 Satellite (click image for loop):



Invest 92L Track Models:



Hurricane Igor Visible/IR2 Satellite (click image for loop):



Hurricane Igor Track Models:



Hurricane Julia Visible/IR2 Satellite (click image for loop):



Hurricane Julia Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






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Monsters and Minions, and the threat for SW Atlantic mischief by the end of the month

By: Levi32, 4:09 PM GMT on September 13, 2010

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems or questions about the video.



Invest 92L is pretty much an open wave now, but still a very sharp, amplified wave with convection going off along the axis. I still think this will find a way to develop eventually, either in the western Caribbean or the Gulf of Mexico. This system will be crossing the Yucatan and likely hitting Mexico twice, though southern Texas should keep an eye on this in case it tries to fade northwest at the end, which is possible especially if Igor takes a farther west track.

Speaking of Igor, he is the most beautiful hurricane yet of the 2010 hurricane season. I don't know why this isn't a Cat 5, but Dvorak estimates put it at a Cat 4 which is why the NHC didn't upgrade him. Igor is still stubbornly moving south of west, contrary to all of the models and the NHC forecasts, as expected really. They are all too far north and east with this in my opinion. The first trough has done nothing to Igor's movement, and trough #2 will have its work cut out for it to get Igor to curve up east of Bermuda. The models/NHC have Igor crossing 20N before 55W. He's currently at 17.5N and 50W moving south of west.....I say no way.

I still feel that recurvature east of the US is the most likely scenario here, but much farther west than the models have it. I think this probably will end up splitting the uprights right between Hatteras and Bermuda, but it's going to be a tough forecast. Some of the big-hitting ensembles are showing some scary stuff with a massive split between recurvature and the potential for a WNW track continuing right into the Bahamas. The Japanese model is still in the southern camp as well, though it will be interesting to see the new 12z run in a few hours. The eastern seaboard should definitely keep their eyes on this, as it is far from a done deal. When you see a hurricane moving south of west in defiance of every model, you must worry a little bit. Bermuda, however, is at most risk from this, and even a track 100 miles to the west would be devastating for them. They should be watching this the closest right now.

In other news....the models are starting to echo my thoughts on the SW Atlantic Basin lighting up by the end of this month, and the GFS ensembles are now consistently showing a bomb of low pressures in the vicinity of Cuba in 2 weeks, with the operational lending support by showing a major hurricane in the area on several runs. Specifics can't be trusted, but the message is that as the Cape Verde season starts to wind down the activity won't go away, it will just simply shift west, and the SW Atlantic Basin will be taking up the slack and hosting some storms of its own before the season is over. The worry is that storms forming farther west also track farther west, and that means land areas are likely to be affected by whatever may form. We will have to see if there is a hurricane sitting south of the US during the final days of September. Keep your eyes open.

We shall see what happens!

Invest 92L Visible/IR2 Satellite (click image for loop):



Invest 92L Track Models:



Hurricane Igor Visible/IR2 Satellite (click image for loop):



Hurricane Igor Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






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Could Igor threaten the US? 92L to threaten Mexico and Texas

By: Levi32, 5:24 PM GMT on September 12, 2010

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems or questions about the video.



The Atlantic is getting very active again as we start a new week. TD 12 has developed near the Cape Verde Islands and will likely be named Julia soon. Invest 92L continues to develop slowly in the Caribbean as thunderstorms today are building more around the center, which is starting to become better-defined. Now that we can see where the center is trying to consolidate the track may end up being a little south of where I had it, and this will probably pass closer to Jamaica or a little south thereof, instead of to the north. 92L will likely run into the Yucatan and then enter the western Gulf of Mexico, threatening northern Mexico or south Texas late this week.

Hurricane Igor has rapidly strengthened overnight and looks like a major hurricane now. The NHC at 11am put him at Cat 2 but I think he's already pushing Cat 4, and will likely make a run at Cat 5 at some point.

Igor's track remains a great debate amongst the models. The ECMWF operational continues to recurve this but last night's 0z was the farthest west run yet, all the way back to 71W before recurvature. The majority of the Euro ensembles though continue to show Igor within striking distance of the SE US coast, much farther southwest than the operational run. The Euro has dropped us a major clue in that it now takes what will probably be Karl (92L) northwest in the western gulf, more towards south Texas, and this is very different than the west or even SW movement that it had been showing in the Bay of Campeche. A storm fading northwest implies more of a trough digging into the west-central US and forcing the Texan ridge to build further east and connect to the Atlantic ridge, which would ultimately lead to a further west track for Igor.

The Japanese model is still designated the "what if" model for this storm, as it takes the pattern and formulates something that makes meteorological sense, which ends up bringing Igor right into the southeast US coast in 10 days. This is a scary thought, but the JMA is still the outlier on this one for now. Although there are still some things that argue for recurvature, I don't think the eastern seaboard can take their eyes off of this, as it could end up being another close call like Earl, perhaps bringing some impact to the coast if not a direct landfall. Bermuda also has to watch this in case it recurves close enough to them, and considering how large Igor is likely to be, it doesn't have to be that close.

The bottom line is that we may have 2 different storms threatening the US coast within a few days of each other during the next 10 days, and people should be on guard.

We shall see what happens!

Invest 92L Visible/IR2 Satellite (click image for loop):



Invest 92L Track Models:



Hurricane Igor Visible/IR2 Satellite (click image for loop):



Hurricane Igor Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 5:29 PM GMT on September 12, 2010

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92L better organized; Igor could threaten Bermuda or even farther west

By: Levi32, 6:01 PM GMT on September 11, 2010

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems or questions about the video.



Firstly I would like to just remember the victims of the 9/11 attacks, the 9th anniversary of which we mourn today. Our hearts and prayers go out to their families.

Invest 92L is blowing up a lot more convection this morning as the eastern Caribbean starts to get better-ventilated, and the exact location of the center is unknown, but I still like the track idea of having this come up into the "triangle" between Cuba, Jamaica, and Haiti. From there this will likely skirt the NW Caribbean and turn west across the Gulf of Mexico, likely threatening northern Mexico down the road. With the big central US ridge staying strong for the next several days it will be hard to get this to come into Texas, but a track far enough north could do it. I think Mexico is most likely to see a landfall, but the entire west gulf coast should keep an eye on this, as well as the Caribbean islands. Development will be gradual for the next few days, not explosive, but with the record hot water in the western Caribbean and plenty more in the Gulf of Mexico, this is something that should be watched very closely.

Igor continues to churn in the eastern Atlantic. Some dry air finally got into the core which is causing convection to wane this morning, but an eye feature has been trying to develop and this will likely become a hurricane sometime tonight. Igor is destined to become a big major hurricane down the road, and it's not guaranteed that this will be a fish storm.

The pattern for the next 10 days has a polar vortex diving into Canada with blocking over Alaska, and this is a pattern that would normally argue for height rises over southeast Canada and the northeast US. With some of the normal model errors one has to wonder if Igor will come farther west. This could be a big threat to Bermuda, and a track even farther west, closer to the eastern seaboard west of 70W is possible, similar to Earl. The Japanese model shows a very scary worst-case scenario where the Canadian trough digs into the midwest and forces the central US ridge to connect to the SW Atlantic ridge, steering Igor right into the southeast United States.

This is an outlier solution but one that we should keep a wary eye out for in case Igor hangs back farther south than the models think, which has already happened multiple times this season. With the MJO taking a detour into octant 4 it favors more troughing near the eastern seaboard, which is why I think recurvature east of the US is still most likely, but Igor should still be watched and again I think Bermuda needs to be especially vigilant.

We shall see what happens!

Invest 92L Visible/IR2 Satellite (click image for loop):



Invest 92L Track Models:



Tropical Storm Igor Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 6:04 PM GMT on September 11, 2010

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92L may be a problem; Igor to become a major hurricane

By: Levi32, 5:01 PM GMT on September 10, 2010

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems or questions about the video.



The main attraction in the Atlantic remains Tropical Storm Igor, which is now consolidated into a well-defined and vigorous circulation which is still experiencing some easterly shear, but the center will eventually be pulled underneath the ball of deep convection and this will just take off like gasoline. This will be our next major hurricane and possibly a very strong one. The big tropical wave in front of Igor is clearing out most of the dry air and allowing him to develop and strengthen a bit farther east than our other Cape Verde storms have this year, which tended to wait until 50W-60W to intensify.

A feature closer to home is Invest 92L near the southern Antilles which is now separating from the ITCZ and still has a broad, ill-defined circulation. Large-scale subsidence currently over much of the SW Atlantic Basin is going to be inhibiting any rapid development of this, but with a trough digging into the western Atlantic over the next couple days, the Caribbean should start to get more ventilated, and I expect 92L will undergo slow and gradual development.

If 92L survives and develops, the track will become a major issue. Right now the model spread is still very large. The HWRF and GFDL are I think too far poleward as usual, and the Canadian has been joining them thus far. In the southern camp we have the BAM suite, the GFS which doesn't show development anymore, and the European. I think these are a little bit too far south, and I like a track up into the "triangle", the area between Cuba, Jamaica, and Haiti in 4-5 days. The logic here is that the trough digging into the western Atlantic will cause enough of a break in the ridge over the northern Caribbean to allow 92L to lift north and gain some latitude before being turned back WNW under the ridge.

A southerly track like the ECMWF puts Mexico at risk, but a track further north closer to Cuba puts Texas in the threat area as well, and potentially even the other gulf states. There is still uncertainty with this pattern, and the models will be flip-flopping a lot with this system, so everyone in the Gulf of Mexico and the big Caribbean islands should keep a close eye on this system. Regardless of development, heavy rains will likely move into Hispaniola, Jamaica, and Cuba as this system passes by.

The pattern is one that will favor the SW Atlantic Basin lighting up more during the 2nd half of September, and there is also the danger that one of these Cape Verde storms could make it all the way across and threaten the United States. It remains to be seen whether Igor will try it. I think he's more likely to recurve east of the US than not, but he should be watched, as well as the storm behind him.

We shall see what happens!

Invest 92L Visible/IR2 Satellite (click image for loop):



Invest 92L Track Models:



Tropical Storm Igor Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Permalink

Caribbean to host a new storm; Cape Verde train is renewed

By: Levi32, 4:45 PM GMT on September 09, 2010

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems or questions about the video.



I messed up and said "Juliet" throughout the video instead of Julia...lol.

Things are starting to heat up again now in the Atlantic. We have Igor in the eastern Atlantic which will take its time getting together over the next couple days, but I think will eventually become another powerful hurricane. The models still say recurvature and given the negative AO and NAO causing shorter wavelengths that might make sense, but it should still be watched in case it gets trapped.

However, of far more concern is Invest 92L, an area of low pressure developing within the ITCZ just east of the Antilles Islands. Widespread convection is associated with this system. There is dry air to the north and limited outflow channels but this situation should gradually improve over the next few days as the ITCZ continues to moisten the Caribbean and an upper anticyclone develops over the area. Given these short-term limiting factors and the fact that the low is embedded in the ITCZ, I am calling for slow, gradual development, though we could be looking at a tropical depression in as soon as a couple days.

The steering flow west of 60W is almost nonexistent right now, thanks to the pattern of lower than normal pressures across the SW Atlantic Basin and higher than normal pressures across northern South America. This is what is allowing the ITCZ to lift northward out of South America and into the Caribbean, and is also why 92L will be taking its sweet time coming westward over the next several days. The models generally agree on 92L making it into the western Caribbean in 6-7 days, a very slow pace. This is rather dangerous because the slow air flow through the Caribbean means air is allowed to pile up, and with ocean heat potential through the roof in the western Caribbean, the Yucatan Peninsula and Cuba will want to be keeping an eye on this very closely.

The future track of 92L is rather uncertain given both the weak steering flow and the dynamic pattern aloft across the northern hemisphere. The ECMWF and GFS operational models take 92L pretty much straight west across the Yucatan and into Mexico beneath a strong ridge over the central US that would protect the northwestern gulf coast.

However, the CMC, NOGAPS, and half of the ECMWF ensemble members think that the trough coming off the eastern seaboard in a few days that will be trying to recurve Igor will cause enough of a weakness in the ridge north of 92L to allow the system to lift northward over the eastern Caribbean and approach Hispaniola or Cuba before turning west under the ridge. This weakness would not be enough to recurve 92L, but if it gains that much latitude before turning west, it could open up the United States gulf coast for a potential landfall instead of just Mexico.

Much of this is still largely unknown as the weak steering flow will likely put a gulf coast landfall up to 10 or more days away. The pattern is fragile and the models are handling it differently from run to run, so flip-flops will be expected. The situation will have to be analyzed and reanalyzed as time goes on, but the overall message here is that the Caribbean is coming to life for the first time since Alex, and unlike a Cape Verde storm, this one, which would be Julia or Karl, would be almost guaranteed to hit land.

This could be the start of the pattern shift which will be starting to amplify as this month goes on as the Cape Verde season starts to shut down and the activity shifts west into the Caribbean, where the United States could face their biggest threats yet this season, as well as Mexico and the other Caribbean countries. This is the foreshadowing of what late September and October may be like. With the ridging over the eastern US and the record warm water in the Caribbean, this is not something to be taken lightly.

We shall see what happens!

Invest 92L Visible/IR2 Satellite (click image for loop):



Invest 92L Track Models:



Tropical Storm Igor Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Permalink

Igor forms; SW Atlantic Basin getting ready to light up

By: Levi32, 4:24 PM GMT on September 08, 2010

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems or questions about the video.



Well I think I have found a way to try to do some updates in the mornings again. This week I'll be really settling into my class schedule so I hope to have time to do these as part of my routine. I can't promise that I'll be able to put these up every day, but I will try.

The Atlantic is fairly quiet since Hermine moved ashore dumping large amounts of rain on Texas, but we have a brand new tropical storm in the far eastern Atlantic, Tropical Storm Igor, centered just southeast of the Cape Verde Islands. This is one of the more intimidating names on the storm list this year, and I think he has a good chance to live up to his name and become a major hurricane down the road. He should have less problems with dry air than Danielle and Earl did, as he has a nice large tropical wave out in front that is bringing a potent moisture burst into the Atlantic.

The models will be jumping around trying to recurve Igor into a weakness in the central Atlantic in about 10 days. There is room for a lot of change to this idea as the pattern is very dynamic, and a lot of models are showing drastically different things from run to run, indicating the uncertainty in this kind of pattern. The European and GFS both show another storm developing behind Igor in a few days and try to recurve it early. What could be interesting is if the storm behind Igor does recurve early, amplifies the trough into the eastern Atlantic, and pumps the ridge to the west which would prevent Igor from turning out as soon. This is speculation for now as it is a long way out, but I am still very concerned that the pattern this year may allow at least one of these Cape Verde storms to come all the way across and hit the United States.

The ECMWF has been fairly consistent on developing a storm in the Caribbean in 8-10 days as heat builds up and pressures lower in the SW Atlantic Basin. It is about time for this area of the Atlantic to get going. The Caribbean has seen nothing since Alex at the very beginning of the season. The models are starting to see the upward motion shift west towards the Caribbean after being focused over Africa during the Cape Verde storm burst, and this makes good sense given that the Cape Verde season typically starts to slow down during the 2nd half of September. August is the most active month for the eastern Atlantic climatologically, and once that area starts to shut down for the year, the activity is just going to shift west into the SW Atlantic Basin where storms are very likely to threaten land. We've already had Hermine as a warning shot that things will start to get active over there.

Just because most of our storms have been of Cape Verde origin this year doesn't mean that the season will end when the eastern Atlantic shuts down. The activity will simply shift west, and that's why the U.S. should still be very concerned about potential landfalls in the 2nd half of September and October. The Gulf of Mexico is a hot spot and deceptively favorable for storms that could get in there. Bonnie and a couple of TDs have made it seem like it's been unfavorable, but in reality it has been very favorable on average, but no storms have gotten in there to take advantage of it. We saw how fast Hermine tried to ramp up. It is not something to take lightly. I still expect a few more storms to hit the United States before the season is over.

We shall see what happens!

Tropical Storm Igor Track Models:




Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






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About Levi32

Levi Cowan has been tracking tropical systems since 2002, and is currently working on his bachelor's degree in physics at UAF.

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