Debby Dissipates; Tropical Outlook for July
After over 5 days of tormenting forecasters everywhere, Tropical Storm Debby dissipated just off the east coast of Florida as of the 5PM advisory from the National Hurricane Center. Debby proved to be one of the greatest forecasting challenges of all time, particularly in its track forecasts, as models struggled to agree on a Florida or Texas landfall. In the end, the GFS model performed the best by far, as it was the only model to consistently bring Debby into Florida. Intensity forecasts were tricky also, mostly because of changes in the track forecast. Original predictions for Debby to become a hurricane fizzled, and she peaked with winds of 60mph. Debby's biggest impact by far was torrential rainfall across Florida, with some amounts exceeding 30 inches in localized areas. This triggered serious flooding.
Figure 1: Remnants of Debby
Figure 2: Tropical Storm Debby turned roads into rivers in Florida. (Photo courtesy of USA Today)
Debby's remnants are located over a marginal environment for restrengthening. Some models do redevelop the system, and the NHC has indicated this as a possibility in its 5PM advisory. I do not personally see Debby redeveloping.
Outlook for July
At this point it appears unlikely we will see anymore development in June as we approach the end of the month. A tropical wave is currently located about 1500 miles east of the Windward Islands. It is being given a 10% chance of development in the next 48 hours by the National Hurricane Center. I do not foresee development of this disorganized system, and I give it a near 0% chance of developing in the next 48 hours.
Figure 3: 8PM TWO from the NHC, showing the small, disorganized wave mentioned
Looking out farther, it appears the Atlantic will be very quiet during the month of July. The main reason for this will be the loss of the MJO that helped form Tropical Storm Debby. Having the MJO is key to development before August. In addition, wind shear is high in the Caribbean where we would typically look for development this time of year.
Figure 4: Atlantic wind shear map.
These factors will make it difficult to get any storms of truly tropical origins through at least July 20. It is much harder to predict storms of non-tropical origins like recent Hurricane Chris. I think we will probably see one of these at some point this month, so I believe we will see Ernesto in July. With El Nino approaching, August is the month to watch this year as activity will mostly shut down by the end of September. At this point a total of 11-13 named storms still seems likely at this point.
Tropical Storm Dukshuri is currently drenching the northern Philippines. It currently has winds of 40mph, and slight strengthening is forecast as it heads towards a final landfall near Hong Kong Friday or Saturday. Heavy rains will be the biggest concern.
Figure 5: Tropical Storm Dukshuri. The deepest convection is well west of the center.
I've mentioned this on Dr. Master's blog a couple times this week, but I'll mention it again here. It's been my pleasure to work at the Blue Hill Observatory in Milton, Massachusetts over the past two days. Home of the oldest set of continually recorded weather data in North America, it's truly an amazing facility and it's an honor for me to work there this summer. I contributed in the writing of the daily discussion today, which you can find here. My name is Jonathan (there's a typo in the discussion, it's spelled Jonathon there instead of Jonathan). I wrote it with the Observatory's chief observer Mr. Robert Skilling, who has worked there for over 50 years.
Thank you as always for reading, and have a great rest of your week!
Updated: 12:16 AM GMT on June 28, 2012
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96L Could Become Serious Gulf Coast Threat
I'm glad to be back here after a fun few days on Cape Cod! The Atlantic is active this evening, with former Hurricane Chris falling apart over the far northern Atlantic, and a new system coming together in the southern Gulf of Mexico. This disturbance, 96L, is being given a 70% chance of development in the next 48 hours by the National Hurricane Center. I put these odds slightly higher at 80% because of the favorable conditions 96L is in.
Figure 1: Invest 96L
Figure 1 shows that 96L is in a moist environment. It is also in a low shear environment. It is also over the warm seas of the Gulf of Mexico. This is a potentially dangerous situation if these ingredients combine like they could. 96L is a large distrurbance, so I believe the key to the forecast is how fast the system consolidates into a depression and storm. As usual, the models are all over the place, with both track and intensity. I think today's 12z Euro run is a pretty realistic scenario though.
Figure 2: 12z Euro run at 168 hours
An intensity like this seems realistic to me, with the track possibly being a little too far west. A track into far east Texas or western Louisiana seems likely to me, with the odds of impact on Florida and Alabama pretty low (though early 0z models have shifted east). Right now track forecasts aren't too important. Models will begin to come into agreement on track more when they come into agreement on intensity. Regarding intensity, here are three possible scenarios:
1. 96L takes a longer than expected time to consolidate because it is so large. It tracks along a higher shear path and peaks as a moderate tropical storm.
2. 96L develops in 24-36 hours from now and tracks through the favorable Gulf environment, steadily strengthening and peaking as a Cat 1 or 2 hurricane.
3. 96L develops faster than expected. It gets more time over favorable conditions as a developed cyclone and performs RI like some storms do in the Gulf. It peaks as a high end Cat 3 hurricane.
The bottom line right now is that a lot can and will change. Anyone on the Gulf coast, especially from Pensacola Florida to Corpus Christi Texas, should watch this storm closely as it could become a major threat. I will have more updates in the coming days. I could make more predictions now but it would be more guesswork than anything else, so I'll keep this one short and wait to make any big predictions.
Thank you as always for reading. This definitely isn't my best work since I've been gone a few days and haven't seen all the available information, but I think the main point was brought out okay, and that is that we finally have a real, threatening system to track! Enjoy the rest of your week!
Guchol To Hit Japan; Atlantic Quiet
There is only one tropical cyclone on Earth right now, and that is powerful Super Typhoon Guchol in the West Pacific. Guchol is currently moving NNW at about 15mph and will soon take a more north and then northeast turn according to the official forecast. It currently has maximum sustained winds of 130 kts according to the Joint Typhoon Warning Center, making it a high end Category 4 typhoon. It is forecast to begin weakening soon and likely already has, slowly, as the remainder of its forecast track brings it over cool waters, high wind shear, and dry air.
Figure 1: Official forecast path of Guchol.
As Figure 1 shows, Guchol will likely track by and into Japan on Tuesday. This track has been shifted significantly west since yesterday, meaning a direct hit on Japan is very likely. Luckily, due to the hostile conditions, Guchol will be falling apart as it heads into Japan, but it will still pack quite a punch. Strong, hurricane force winds will be likely, especially in coastal areas. The biggest concern however will be heavy rains as Japan is currently very saturated from recent wet weather. Storm surge will also be a concern. Luckily Guchol will be accelarating rapidly as it passes Japan, so it won't stall out and cause bigger problems.
Figure 2: Despite starting to slowly weaken, Guchol remains an extremely dangerous, well organized storm.
Figure 3: Possibly the next West Pac storm, Invest 92W currently has a TCFA on it.
Meanwhile, the Atlantic is mostly quiet this 17th day of the season. A non tropical area of low pressure is currently located just over 100 miles SSW of Bermuda, drifting NNE at about 15mph. Slow development of the low is possible over the next few days, and the National Hurricane Center gives it a 10% chance of becoming a tropical or subtropical cyclone in the next 48 hours. I give it about a 30% chance of developing at any point in its lifespan. There remains considerable uncertainty as to a potential storm developing in the Gulf of Mexico in about 5 days time. I give development there during the next week about a 50% chance at this time. At this point it appears anything that develops will remain fairly weak and short lived, but as ususal with Gulf systems it should be closely watched if it does develop.
Finally, in the East Pacific, former Hurricane Carlotta dissipated yesterday over the mountains of Mexico. While it is no longer a tropical system, it still will provide a threat for heavy rains that could trigger life threatening flooding and mudslides. Two people have already been killed by the storm.
I had to get this blog out today because I'll be leaving for Cape Cod tomorrow afternoon and staying a few days to escape an impending Northeast heat wave, with temperatures expected to soar into the 90s Wednesday through Friday. Thank you for reading, and have a great week!
Carlotta Slams Mexico, Guchol Takes Aim at Japan
We have two very powerful hurricanes on planet Earth this evening. The first is in the East Pacific, Hurricane Carlotta. Carlotta was a tropical storm this morning, but underwent a classic case of rapid intensification for much of the day, helped by extremely warm waters and favorable atmospheric conditions. It is making landfall in Mexico as I write as a category 2 hurricane with 105mph winds.
Figure 1: Official Forecast Track of Carlotta.
The track, as seen in Figure 1, is a worst case scenario for Mexico, as it is expected to hug the coast as it spins down. This means that in addition to hurricane force winds at the coast, Carlotta will likely dump 7-9 inches of rain over a large part of Mexico with isolated 18 inch amounts. Flooding, flash flooding, and mudslides will be a major concern. As far as intensity, there isn't much to say at this point.
Figure 2: Hurricane Carlotta
Figure 2 shows Carlotta does not have a very well defined eye anymore and has peaked in intensity. It's possible the storm was stronger than the listed 105mph peak, but we'll have to wait until the post season to know that. The official forecast brings the storm down to 80mph in 24 hours, however I believe it will be a tropical storm by then as the rugged terrain of Mexico shreds the system apart. Any redevelopment after Carlotta reemerges over water is unlikely.
Guchol Targets Japan
Meanwhile on the other side of the world, Typhoon Guchol is plowing through the West Pacifc Ocean with maximum sustained winds at 100kts according to the Joint Typhoon Warning Center, making it a category 3 typhoon. The storm is currently west of the northern Philippine islands and is moving NNW at about 12mph. A turn more towards the north and northeast is anticipated soon as the system prepares to recurve, as seen on the forecast track in figure 3.
Figure 3: Official forecast track of Guchol
At this point it appears the storm will make landfall near Tokyo. The question is how strong will it get. The JTWC forecasts the storm to reach 125 kts in 48 hours, which I think is reasonable, maybe just slightly too high. After that, however, things get complicated as Guchol will encounter extreme amounts of wind shear and much cooler waters as it transitions into an extratropical cyclone. This will weaken the storm, but I'm hesitant to buy into the JTWC forecast for the storm to go from 105kts to 65kts between 72 and 96 hours. Powerful storms like Guchol take time to spin down. By the time it reaches Tokyo it will probably look like crap after taking a beating from so much shear but I think it's entirely possible it will still have some category 2 winds as it speeds through. The interaction between Guchol and these unfavorable conditions is not easy to predict however, and it's possible the storm could end up far weaker than what I and the JTWC think if it doesn't reach its forecast peak and begins weakening sooner than expected. The people of Japan should watch this closely as a lot can change.
Figure 4: Looks can be deceiving. While Guchol doesn't appear to have an eye, it does, but it is so small it's only visible on microwave imagery!
The Atlantic is quiet right now. There are many potential scenarios about some storms that may develop sometime at some point, but as you can tell from my wording there, I'm not worried about it right now. Models have been so all over the place that as of right now I don't see any development before the end of June. We'll see.
Thank you as always for reading! I should have an update tomorrow on Guchol. Enjoy your weekend!!
Carlotta Threatens Mexico, Guchol Threatens Japan
The tropics are very active across the globe today. The majority of the action today is in the East and West Pacific Oceans. In the East Pacific, Tropical Storm Carlotta formed early this morning from a disturbance previously known as 94E. It now has maximum sustained winds of 45mph and a minimum pressure of 1000mb according to the National Hurricane Center. Carlotta is forecast to strengthen into a hurricane by the NHC with a forecasted peak intensity of 90mph as it nears the Mexican Coast. The official forecasts brings it very close to the coastline.
Figure 1: Official NHC forecast track of Carlotta
While the track does not indicate an official landfall, it will be plenty close enough to the Mexican coast to provide hurricane conditions, and for that reason hurricane watches and warnings are in effect for a large area of the coast.
Figure 2: Water vapor imagery of Carlotta
As Figure 2 shows, Carlotta is struggling a little with dry air, preventing it from consolidating its thunderstorms around the center. I think it will overcome these issues, but it may take the rest of the day, meaning the NHC's forecast for Carlotta to reach 60mph by 11PM tonigt may be too aggressive. Still, I think that once Carlotta resolves this problem she will intensify and probably peak at an intensity of 85mph, with an outside chance of 100mph if rapid intensification occurs soon after the dry air is worked out of the circulation. I also believe that the steering currents, mostly a trough to the storm's west, will be a little slower to move than forecast, causing a longer period of northwest motion which will lead to an official landfall. I also think Carlotta will weaken some before landfall. The NHC has Carlotta peaking as she gets to the coast, but I think the peak is likely to happen sooner beofre slight weakening, probably to a minimal hurricane, occurs before landfall. Impacts will not change much regardless, with the main threats being strong winds near the coast and torrential rain a bit further inland. The mountains of Mexico will help wring out a lot of moisutre, and because it will sit near the coast for a while, I think 5-9 inches of rain are likely in many areas with highly localized amounts of 15 inches possible. This situation bears close watching by the people of Mexico.
Guchol Targets Japan
In the West Pacific, powerful Typhoon Guchol is taking aim at Japan. According to the Joint Typhoon Warning Center the storm currently has winds of 80mph. It is forecast to reach near major hurricane stregnth in about 3 days before it beigns to become extratropical as it recurves towards Japan.
Firgure 3: Official forecast track of Guchol
On its forecast path Guchol will either make landfall on Japan or pass just east of the country.
I'm worried about this storm. All the conditions are there for it to rapidly intensify during the next 48 hours. It is in a moist, low shear environment and over extremely warm waters. In additions, rather than beginning a west-northwest motion like the offcial track suggests, it has moved due west or even a bit south of due west all day, which keeps it over favorable conditions longer and increases the odds of a Japan landfall. For these reasons I am forecasting a peak intensity of 125 mph and a landfall on Japan. Figure 4 shows Guchol looks quite impressive at this time and will likely clear out an eye soon.
Figure 4: Typhoon Guchol
Both Carlotta and Guchol are potentially dangerous and life threatening storms that bear close watching by those who could potentially be affected. I will have an update tomorrow or Saturday. Thanks you as always for reading, and have a great day!
Updated: 4:59 PM GMT on June 14, 2012
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Tropical Outlook for the Next 2 Weeks
Nearing the midway point of the first official month of the 2012 Atlantic Hurricane Season, we have yet to see one June storm to follow up on our rare two May storm, Alberto and Beryl. We also haven't yet seen any activity in the East Pacific this month. There is a real chance that will change in the coming two-three weeks however.
As the above figure shows, an MJO pulse is on the way for the Atlantic. This is an indication that conditions in the basin will be conducive for development for the next 10 days or so at least. Over the past week or so the models have struggled to decide on what to do with these favorable conditons. Among some of the possibilities they have shown are a weak Caribbean storm, mostly supported by the GFS, a weak storm off the East Coast, supported by several models, a storm northeast of the Bahamas, also supported by multiple models, and a Gulf of Mexico storm which has mostly been supported by the NOGAPS but has occasionally seen hints of support from other models.
It's not easy to decipher the truth from these models, but here's my best attempt at it:
1. The potential storm off the East Coast and the potential storm northeast of the Bahamas have the most model support, so I think we have our best chance of getting Chris and/or Debby out of this area. One potential issue we could have with these storms would be whether they are tropical or non-tropical since the models have been bouncing back and forth on that issue.
2. For about the past week the GFS has been persistently showing a weak storm forming in the Caribbean and fading out before it really does anything. This solution has not seen much support from other models but I think a low will form in the Caribbean and most likely be strong enough to at least get a TD based on the fact that conditions will be conducive for development there.
3. While it did not do this during today's 18z run, the generally unreliable NOGAPS model has been consistently shwoing a strong tropical storm/weak hurricane in the Gulf of Mexico towards the end of its runs for the past 2 days. No other models have supported anything like this, but some have shown a few hints of weak low pressure possible in the Gulf arounnd that time. At this point I think it's an outside chance we get anything in the Gulf during the next 2 weeks, but anything that does form there should be watched as conditions would be conducive for some further development.
So, my official prediction is that in the next 2 weeks we will see two storms: Chris off the East Coast in 2-4 days and Debby in the Caribbean in 4-6 days, with neither storm surpassing an intensity of 50mph and neither posing a significant threat to land area, though the Caribbean system could present minor flooding concerns. My reasoning is as follows: It's very likely a low will emerge off the East Coast and most indications are that it will be strong enough to earn a name, leaving only the question of warm core vs. cold core. I think SST's and overall atmospheric conditions will be favorable enough for at least a subtropical system. And I think the Caribbean system has a good chance simply because conditions will be favorable there so any low that forms should strengthen into a tropical storm.
Conditions also appear conducive for development in the East Pacific over the next two weeks, and indeed we have two invests out there right now. There is also a tropical storm in the West Pacific that is likely to become a typhoon. However, as I have final exams to be studying for right now, I will elect to write a new blog on these areas tomorrow or Thursday if I can.
Thanks as always for reading, and enjoy the rest of your week!
Updated: 12:34 AM GMT on June 13, 2012
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