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Twin Major Hurricanes Menace Hawaii; Little Change to Atlantic's TD 8 and TD 9

By: Jeff Masters and Bob Henson 3:59 PM GMT on August 30, 2016

Powerful Hurricane Madeline continues edging toward Hawaii’s Big Island, where a Hurricane Watch remains in effect. An astounding 36-hour burst of intensification peaked early Tuesday, with top sustained winds of 135 mph at 5 am EDT making the hurricane a Category 4 on the Saffir-Simpson Scale. As of 11 am EDT Tuesday, Madeline’s top winds were down to 120 mph. The formerly distinct eye has become obscured in infrared imagery over the last few hours, another sign of weakening. Wind shear will increase to the moderate range (15 - 20 knots) by Wednesday, so we can expect at least gradual weakening to continue.


Figure 1. Hurricanes Madeline (left) and Lester (right), as captured by the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi NPP spacecraft on Monday, August 29, 2016. Image credit: NASA.

Located about 450 miles east of Hilo as of 11 am EDT, Madeline was moving west at 10 mph. Computer models agree that a strengthening ridge to the north of Madeline will help induce a leftward bend in Madeline’s track. This bend, plus interactions with Hurricane Lester (see below), may be enough to put Madeline’s track just south of the Big Island and well south of the rest of Hawaii, but there is still some uncertainty about this. The 00Z UKMET and the 06Z HWRF and GFS model runs keep the hurricane about 100-200 miles south of the island, while the 00Z European and 06Z GFDL run suggest a landfall on the Big Island at hurricane strength. No hurricane has ever struck the Big Island in records going back to 1949. The official track from the Central Pacific Hurricane Center brings Madeline within 50 miles of the south tip of the Big Island on Thursday morning, putting the island on the more dangerous right-side (north) side of the storm.


Figure 2. Tracking map for Hurricane Madeline as of 11:00 am EDT (5:00 am HST) Tuesday.

Although models diverge on how quickly Madeline will weaken, the 11 am EDT Tuesday outlook from CPHC projects that Madeline will be a Category 1 hurricane by the time it reaches the vicinity of Hawaii. Even a brush just to the south of the Big Island at this strength would push very strong tropical-storm-force winds into the east side of the island, slamming upslope against towering mountainsides. The result would be torrential rains of 5” - 15” or more and the potential for flooding and landslides. Winds could be strong enough to produce considerable damage to trees, power lines, and roofs. Surf is expected to reach 15 to 25 feet on east-facing shores by Wednesday, with significant damage to roads and coastal properties possible. For more details, refer to the local statements that are compiled on a CPHC website; these will be updated as Madeline approaches.


Figure 3. Infrared satellite image of Hurricanes Madeline (center) and Lester (right) as of 1200Z (8:00 am EDT) Tuesday, August 30, 2016. Image credit: NASA/MSFC Earth Science Office.

Next up for the weekend: Hurricane Lester
The 50th state has another storm to keep an eye on: Hurricane Lester. Peaking on Monday night with top sustained winds of 140 mph, Lester weakened slightly overnight, but on Tuesday morning it was rebuilding a very solid and well-structured core of convection. Located about 1350 miles east of Hilo and about 900 miles east of Madeline, Lester was packing top sustained winds of 120 mph as of the 11 am EDT advisory from NHC.

Lester’s current westward track is expected to bend to the west-northwest as it approaches Hawaii, which should produce a track over the weekend roughly parallel to the island chain and most likely 100-200 miles to its north. Model guidance is tightly clustered around this track, which is reflected in the official NHC outlook. Among the 00Z Tuesday runs of the leading models, only the UKMET produces a landfall in Hawaii, and that occurs with a much-weakened Lester. This gives us increasing confidence that Hawaii will dodge the Lester bullet, although there is still enough error in 4- and 5-day outlooks to keep most of the state in the “cone of uncertainty” for now (see image below). Lester is expected to weaken very gradually over the next several days, with more significant weakening possible as wind shear increases toward the weekend. Lester will also be moving over waters churned up by Madeline, which could further dampen its strength.


Figure 4. Tracking map for Hurricane Lester as of 11:00 am EDT (5:00 am HST) Tuesday.

Only five tropical storms or hurricanes have made landfall on a Hawaiian island since records began in 1949, and two of those have been in the last three years (see our Monday post for details). Given Hawaii’s limited experience with tropical cyclones, both Madeline and Lester need to be taken very seriously. An unprecedented deployment of hurricane hunter resources to Hawaii kicked off on Monday afternoon, when three Air Force Hurricane Hunter aircraft were sent to the islands. Beginning on Tuesday afternoon, these aircraft will provide regular fixes every 12 hours on Madeline, and will also begin flying into Lester when it draws closer to Hawaii.

Near-perfect storms
The remarkable strengthening of both Madeline and Lester since Sunday could serve as textbook examples of hurricane intensification. SSTs along the paths of both storms have been on the low side--just above the 26°C benchmark for tropical development—yet both storms have taken full advantage of exceptionally supportive atmospheric conditions, including very low wind shear and very strong upper-level outflow channels. According to output from the SHIPS model, the maximum potential intensity (MPI) for both Madeline and Lester as of Tuesday morning was about 130 knots (150 mph). MPI values take into account the ability of a tropical cyclone to create a “heat engine” based on SSTs and the atmospheric temperature structure. Most hurricanes never reach their MPI value, so that fact that two hurricanes so close to each other have managed this feat testifies to the extremely favorable atmospheric dynamics in play.

Figure 5. The Fujiwhara effect causes two tropical cyclones near each other to rotate around a common midpoint. This motion is on top of the preexisting movement of each cyclone. Image credit: Hong Kong Observatory.

Ironically, the coexistence of Madeline and Lester may help keep either one from a direct landfall on Hawaii, thanks to the Fujiwhara effect, which was discovered nearly a century ago by Japanese researcher Sakuhei Fujiwhara. When two tropical cyclones get within about 800 miles of each other, the interaction tends to make the pair rotate around a common point in between, with the effect superimposed on the storm’s preexisting motions. In a case like this, the easterm storm (Lester) would angle northward and the western storm (Madeline) would angle southward. Both effects would tend to drive Madeline and Lester away from Hawaii.

TD 9 still battling dry air and wind shear
The endless struggle of Tropical Depression Nine with dry air and wind shear continued overnight. The storm’s winds were below tropical storm strength on Tuesday morning, confirmed a NOAA hurricane hunter aircraft, though the central pressure was down 3 mb since Monday morning, to 1004 mb. TD 9 brought heavy rains to Cuba on Monday; In Central Cuba, Trinidad reported 252.4 mm (9.94”) in the 24 hours ending at 8 pm EDT Monday, while Santa Lucia in Western Cuba reported 228.3 mm (8.99”). Additional heavy rains of 2 - 4” are likely over western Cuba on Tuesday. Rainfall amounts of 1 - 2” were common over South Florida on Monday, with a few spots of 3+”.

Satellite images on Tuesday morning showed TD 9’s heavy thunderstorms building, though the circulation center was still partially exposed to view—the telltale sign of a tropical cyclone struggling with wind shear and dry air. Wind shear was a moderate 10 - 15 knots, and water vapor satellite imagery showed plenty of dry air to the storm’s north and west. Sea surface temperatures (SSTs) near TD 9’s center remained favorable for development, near 30 - 30.5°C (86 - 87°F).


Figure 6. Projected 5-day rainfall from 12Z (8:00 am EDT) Tuesday, August 30, through 12Z Sunday, September 4, 2016. Rainfall amounts of 5 - 10” are expected along TD 9’s path across Florida, with up to 12” possible near the coast where the storm makes landfall. Image credit: NOAA/NWS Weather Prediction Center.

Track forecast for TD 9: a Florida Gulf Coast landfall, followed by a run up the Southeast coast
The latest 0Z Tuesday (8 pm EDT Monday) runs of our top models continue to bring TD 9 to a landfall on the Florida coast north of Tampa on Thursday. The models have converged on their timing of this landfall, which is expected to occur late morning or early afternoon on Thursday. In their 11 am EDT Tuesday Wind Probability Forecast, NHC’s highest odds for getting tropical storm force winds of 34+ mph from TD 9 along the Gulf Coast of Florida were 49%, 39%, and 33%, respectively, for Cedar Key, Tampa, and Apalachicola, Florida. Tropical storm-force winds may also occur on the east coast of Florida near where the storm exits the coast after crossing the state: NHC gave odds of tropical storm-force winds of 25% or higher to the Florida coast from Cocoa Beach to Georgia, and to all of the Georgia coast. Lower odds were posted for the South Carolina coast. It is possible the storm could turn north over the weekend just offshore of the Mid-Atlantic coast, as suggested by recent runs of the GFS model. This would bring high surf to beaches from North Carolina to Massachusetts, but the heaviest rains would stay offshore.


Figure 7. Screen shot of NHC’s interactive Storm Surge Probability product from 5 am EDT Tuesday, August 30, 2016, showing the probability of inundation in excess of 4’ above ground level from TD 9. A 30-mile stretch of the Florida Gulf Coast to the right of where the center of TD 9 is expected to make landfall is predicted to have a 50 - 60% chance of getting a inundation in excess of four feet. The graphic is based upon an ensemble of Sea, Lake, and Overland Surges from Hurricanes (SLOSH) model runs created using the current National Hurricane Center (NHC) official hurricane advisory. Storm surge probabilities depend on the historical accuracy of NHC's forecasts of hurricane track, and wind speed, and an estimate of storm size.

Intensity forecast: TD 9 likely to stay below hurricane strength
TD 9 has defied predictions that it would intensify its entire way across the Atlantic as tropical wave 99L, and now as TD 9, so there is reason to be dubious that the storm will ever significantly intensify. Indeed, the latest 00Z Tuesday runs of the GFS and European models show TD 9 as a tropical depression or weak tropical storm with 45 mph winds at the time of landfall on the Florida Gulf Coast on Thursday morning, likely due to the continued presence of dry air at middle and upper levels of the atmosphere. However, we cannot totally dismiss the possibility that TD 9 might put on a sudden show of intensification into a strong tropical storm before landfall on Thursday. The SHIPS model on Tuesday morning predicted moderately favorable conditions for intensification, with wind shear staying a moderate 10 - 15 knots through Thursday morning. SSTs will be a very warm 30 - 30.5°C (86 - 87°F), and mid-level relative humidity was predicted to be a reasonably moist 65%. Our three best intensity models—the HWRF, DSHIPS and LGEM models—were in reasonable agreement with their latest runs available late Tuesday morning, with landfall intensities for TD 9 ranging from 50 - 65 mph. NHC is going with a forecast of a 60 mph tropical storm at landfall. The Gulf Coast of Florida is highly vulnerable to large storm surges, due to the extensive stretch of shallow continental shelf waters offshore that extend up to 90 miles from the coast. On Tuesday morning, NHC was giving a 50 - 60% chance that the maximum height of the storm surge above ground from TD 9 would exceed four feet along a 30-mile stretch of the Florida coast to the right of where the center is expected to make landfall. The other hazard from TD 9 is heavy rain—rainfall amounts of 5 - 10” are expected along TD 9’s path across Florida, with 15” possible near the coast where the storm makes landfall.

TD 8: Tropical Storm Warning continues for the Outer Banks of North Carolina
A Tropical Storm Warning continues for the Outer Banks of North Carolina as Tropical Depression Eight chugs north-northwest at 5 mph towards Cape Hatteras. TD 8 has not strengthened into a tropical storm yet, confirmed an Air Force hurricane hunter aircraft on Tuesday morning, as the plane found top winds in the storm near 35 mph, with a central pressure holding steady at 1011 mb. Satellite images and long-range Morehead City, North Carolina radar on Tuesday morning showed TD 8 continued to struggle to hold onto its heavy thunderstorms in the face of very dry air (45 - 50% relative humidity at mid-levels of the atmosphere), combined with moderate wind shear of 10 - 15 knots. Sea surface temperatures (SSTs) near TD 8’s center remained favorable for development, though, near 29°C (84°F).

Forecast for TD 8: grazing the Outer Banks of North Carolina
The computer models are in excellent agreement that TD 8 will continue on its current north-northwest track through Tuesday afternoon, then make a turn to the north Tuesday night, and then turn to the northeast on Wednesday. These steering currents should bring the center of TD 8 very close to Cape Hatteras, North Carolina on Tuesday night and Wednesday morning. A storm surge of 1 - 2 feet can be expected along the Outer Banks, along with heavy rains of 1 - 3 inches. In their 11 am EDT Tuesday Wind Probability Forecast, NHC’s highest odds for getting tropical storm force winds of 34+ mph from TD 8 were 43% for Cape Hatteras, North Carolina. Dry air and moderate wind shear will continue to affect TD 8 through Wednesday, but there is still the possibility it could become a weak tropical storm by Wednesday.


Figure 8. MODIS visible satellite image of Invest 92L on Tuesday morning, August 30, 2016. The tropical wave was embedded in a large area of African dust to its west and north. Image credit: NASA.

92L emerges from the coast of Africa
A large tropical wave with plenty of spin emerged from the coast of Africa on Monday evening, and was immediately designated Invest 92L by NHC. The wave will move through the Cabo Verde Islands on Tuesday and potentially develop into a tropical depression later in the week. While the latest run of the SHIPS model predicted that SSTs and wind shear would be favorable for development during the coming five days, 92L emerged from the coast at the same time that a major pulse of dust and dry air from the Sahara also left the coast, just to the north. This dry air will greatly interfere with development over the coming days as 92L heads west at 15 - 20 mph across the tropical Atlantic.The latest 0Z Tuesday (8 pm EDT Monday) runs of our three top models for forecasting tropical cyclone genesis, the GFS, UKMET and European models, did not develop 92L over the next five days—though the more recent 06Z (2 am EDT) Tuesday run of the GFS model did develop 92L five days from now. A strong and persistent ridge of high pressure should keep 92L on a fairly straightforward west to west-northwest path, and the storm will likely move through or just north of the Lesser Antilles Islands on Sunday. In their 8 am EDT Tuesday Tropical Weather Outlook, NHC gave this disturbance 2-day and 5-day development odds of 0% and 40%, respectively.

We’ll be back with a new post late Tuesday afternoon.

Bob Henson and Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Any reason why the NHC tosses older advisories? Even googling the result "Public Advisory 8" and clicking on the link that says such, it is replaced with the most recent advisory. Either it's all just updated or they don't want casual users who may need to heed caution stumbling on an older file. I just wanted the previous position to see how soon it may turn N then NE, the longer it takes the closer it might get to me. I'll have to go to the wunderground hurricane center I suppose.
1004. wpb
no question western cuba two feet of rain.and its training over them

Quoting 989. win1gamegiantsplease:

Some strengthening is forecast during the next 48 hours, and the
depression is expected to become a tropical storm tonight or early
Wednesday.


Over/Under: 0500 EDT (0900 UTC)

Put yer money down
Deja vu?
Quoting 997. Bucsboltsfan:



Recently graduated from FSU and still living there.


He's finished, what's he doing now?
Quoting 993. Bucsboltsfan:



I need a translator.


Yep. That's what happens when kids play hooky, they forget how to spell.
1008. BayFog

Hurricane warning just posted for the Big Island as Madeline moves westward. The storm has been downgraded to 100kt.
Quoting 998. IKE:



Latest GFS has a near panhandle hit then turns it more to the east...
what, more of a shift west? they tell me here thats not possible
Quoting 1002. win1gamegiantsplease:

Any reason why the NHC tosses older advisories? Even googling the result "Public Advisory 8" and clicking on the link that says such, it is replaced with the most recent advisory. Either it's all just updated or they don't want casual users who may need to heed caution stumbling on an older file. I just wanted the previous position to see how soon it may turn N then NE, the longer it takes the closer it might get to me. I'll have to go to the wunderground hurricane center I suppose.

There is an advisory archive on the NHC page.
Link
1011. Keen46
Hello all from Orlando FL! Been a long time lurker since the 2004 hurricane season. You guys are great when it comes to getting the latest from the NHC as well as your own personal insight on these systems. I certainly enjoy reading through all the comments. I have a question regarding the track of this system. Is the track shifting towards the west due to the trough expected or is it a result of the intensity forecast for the system slightly increasing? Thanks
Quoting 1002. win1gamegiantsplease:

Any reason why the NHC tosses older advisories? Even googling the result "Public Advisory 8" and clicking on the link that says such, it is replaced with the most recent advisory. Either it's all just updated or they don't want casual users who may need to heed caution stumbling on an older file. I just wanted the previous position to see how soon it may turn N then NE, the longer it takes the closer it might get to me. I'll have to go to the wunderground hurricane center I suppose.


look under archives on the right of the banner
1013. beell
Remain calm, it's mid-level.
:-)



South Texas coast
Quoting 991. Airstorms03:

Hello. I live about 20 miles inland from Charleston and I have been watching TD9 very closely. I see that a few models indicate some high winds over my area. I was wondering which model y'all believe is the best for this?


I'd go with the track the NHC has, and if you're in the cone be aware and prepared. It's not about picking one model at this point, but consensus with several top models.
Quoting 988. GainesvilleGator:

Nobody is talking about the upper level lows (ULLs) to the left & to the upper right of TD9. The one to the left is moving away from TD9 & is diminishing. The one to the upper right of TD9 hasn't moved much today but is shrinking. Both of these ULLs had vigorous spins just yesterday which caused a lot of shear for TD9. Both are fizzling out. The NHC is forecasting less shear in the NE GOM as a result. The LLC & MLC of TD9 don't look too far apart & may finally come together this evening. The NHC issued a Hurricane Watch because a Cat 1 is still on the table.

On a side note if the University of Florida doesn't cancel classes & work on Thursday I will owe a co-worker lunch at Tijuana Flats.



If the sheer don't get you the dry air will.......
1016. IKE
It's all dependent on the trough as to how far west it makes landfall in Florida.
1017. barbamz
Quoting 992. StormJunkie:


I would be astounded if that is what is taking place. But the thought has crossed my mind. It just doesn't seem like either one is moving enough for them to connect.

Vortices in cyclones might be better in compromising than certain political parties lol. Maybe the solution (or just the negotiating table) is in the middle, i.e. the new flare with the green dots?

I am flying Southwest Airlines to Saint Jude children's hospital in Memphis, TN on Monday. We fly out of Nola and our plane stops in Tampa before heading to Memphis. There shouldn't be any problems on Monday, right?

If so, I cancel the flight and fly delta instead since delta stops in Houston or Atlanta rather than Tampa. I'd rather not do this though (it will cost more)

1019. Patrap
Storm Relative 1 km Geostationary Visible Imagery

Click image for loop

  • Don't think 92L going OTS too quickly.
Quoting 1007. ecflweatherfan:



Yep. That's what happens when kids play hooky, they forget how to spell.


Be nice.
I live in Southeast Florida just above Miami and it has been raining since 12this afternoon with thunder and most of the time a heavy rain.. just starting to let up a bit!!
@daddy and fan, thank you.
Quoting 1014. win1gamegiantsplease:



I'd go with the track the NHC has, and if you're in the cone be aware and prepared. It's not about picking one model at this point, but consensus with several top models.

Thanks. I have been and will continue to do so.
Quoting 1013. beell:

Remain calm, it's mid-level.
:-)




And it finally stopped raining on us. :)
Quoting 1018. truecajun:

I am flying Southwest Airlines to Saint Jude children's hospital in Memphis, TN on Monday. We fly out of Nola and our plane stops in Tampa before heading to Memphis. There shouldn't be any problems on Monday, right?

If so, I cancel the flight and fly delta instead since delta stops in Houston or Atlanta rather than Tampa. I'd rather not do this though (it will cost more)




Storm is forecast to be well clear of the area by then. And for whatever reason you are going to St. Jude's - I wish you well.
Quoting 1016. IKE:

It's all dependent on the trough as to how far west it makes landfall in Florida.
ty. so it can still shift more west correct?
Quoting 1018. truecajun:

I am flying Southwest Airlines to Saint Jude children's hospital in Memphis, TN on Monday. We fly out of Nola and our plane stops in Tampa before heading to Memphis. There shouldn't be any problems on Monday, right?

If so, I cancel the flight and fly delta instead since delta stops in Houston or Atlanta rather than Tampa. I'd rather not do this though (it will cost more)




Nope. Should be fine by then. Expected to clear the US completely by midnight Friday night.
Convection continues to increase. And it does appear the MLC is drifting closer to the LLC. ANd vice versa. As barb mentioned. Interesting for sure.

Lets see how far west 99L goes.....either way, if the sky is blue overhead not to worry too much on the Gulf Coast!
1033. Patrap
Perhaps a brush with the northeast this run??
Quoting 1022. mojofearless:



Be nice.


Sorry about that y'all. Speaking of be nice, my "high horse" isn't too tall that I can't get down off of it, or that I won't.
Quoting 1011. Keen46:

Hello all from Orlando FL! Been a long time lurker since the 2004 hurricane season. You guys are great when it comes to getting the latest from the NHC as well as your own personal insight on these systems. I certainly enjoy reading through all the comments. I have a question regarding the track of this system. Is the track shifting towards the west due to the trough expected or is it a result of the intensity forecast for the system slightly increasing? Thanks

I think the reason why the shift to the west is due to the LLC and the Mid LC are not stacked....
The storm has moved more westward than thought. So they moved to cone to the west....

Taco :o)
For those wondering in the Tampa Bay area, what to expect. Looking at the latest GFS model shows about 15-35 mph. sustained winds at the coast with wind gusts of up to tropical storm strength, especially if you live in Pinellas County. I would expect a storm tide running about 1-2 feet above normal, which may lead to coastal flooding along the barrier islands, bayshore blvd, gulf blvd, and any other low lying areas, basically if you flooded during Colin, expect to get flooded again. There will also be heavy rain bands rotating around the periphery of TD 9, so there will be a chance of isolated tornadoes in the right quadrant of the storm. Further north up the coast and closer to the center I would expect tropical storm force winds and even heavier rain bands. Due to a lot of rivers up that way, such as the Anclote River, Withlacoochee, and Indian River, I would expect some river flooding. As always the case for a specific area, consult with your local NWS office which can be found on weather.gov and local news stations for the most up-to-date and accurate information on the storm.
Based on the latest visible satellite it looks like the MLC is about 150-200 miles south of the LLC.
Quoting 1018. truecajun:

I am flying Southwest Airlines to Saint Jude children's hospital in Memphis, TN on Monday. We fly out of Nola and our plane stops in Tampa before heading to Memphis. There shouldn't be any problems on Monday, right?

If so, I cancel the flight and fly delta instead since delta stops in Houston or Atlanta rather than Tampa. I'd rather not do this though (it will cost more)



Should be just fine.

Quoting 1023. oceanblues32:

I live in Southeast Florida just above Miami and it has been raining since 12this afternoon with thunder and most of the time a heavy rain.. just starting to let up a bit!!
I'm with you on that. Pretty heavy most of the afternoon driving through Broward County.
Quoting 863. HurricaneHunterJoe:

Is Indian River near Pensacola?


No-About 150 miles- but they mean Indian Pass. The Indian River is on the east coast.
Quoting 1025. KEEPEROFTHEGATE:



That model looks close to Tampa Metro Esp concerning storm surge and Tampa Metro.
1045. BayFog
Area Forecast Discussion
National Weather Service Honolulu HI
1144 AM HST TUE AUG 30 2016

.UPDATE...
A Hurricane Warning is now in effect for The Big Island including
the adjacent waters. A Tropical Storm Watch remains in effect for
Maui County including the adjacent waters.
Hey everyone.
So I was thinking, in regard to the Hawaiian hurricanes, The models don't seem to account for any terrain interaction with Madeline and the Big Island volcanoes.
What I am thinking is given the latest more westerly than expected motion and the increasing landfall danger, is that if Madeline is highly disrupted by the volcano, it won't have the same influence on Lester as far as Fujiwhara interaction goes.
If this is the case, then could we expect Lester to carry on westward, straight into the island chain, rather than taking the slight WNW motion the Fujiwjara interaction would impart?
If it doesn't take that turn WNW and is under the primary steering influence of just the ridge then I think I could end up wearing that storm for Sunday dinner!
1047. 62901IL
This is the most Gastonic that Gaston has ever been.

There's even dry air in the eye. How does that even happen?
1048. WxLogic
The LLC is currently meandering... the center fix will likely be S of the initial fix of 1004MB
Quoting 997. Bucsboltsfan:



Recently graduated from FSU and still living there.


Unless it has changed in 10 days:

Masters student in tropical meteorology at Florida State University

Link
Quoting 1037. TropicalAnalystwx13:

"95kt"



Gaston has to be a major hurricane again. That's the best looking TC in the Atlantic in years.
Quoting 1044. HurricaneHunterJoe:


That model looks close to Tampa Metro Esp concerning storm surge and Tampa Metro.


The NAM has been one of the most aggressive models with T.D.9. But it's not a tropical model so basically everyone has been discounting it.


what's that obvious swirl in the clouds between the yucatan, and western cuba...just southwest of the current blowup of convection. are those mid level clouds, indicating the MLC? with the LLC further to the north, as shown on nullschool?
Looks like TD9 is forming some spiral bands.
1054. barbamz

(Click to enlarge). Aww, what does this straight line mean? No readings while passing the center?
Quoting 1044. HurricaneHunterJoe:


That model looks close to Tampa Metro Esp concerning storm surge and Tampa Metro.
ya but most disregard it cause its not a tropical model
Quoting 1054. barbamz:


(Click to enlarge). Aww, what does this straight line mean? Now readings while passing the center?


Well that is really aggravating! Maybe they will still post dropsonde data?
Quoting 1047. 62901IL:

This is the most Gastonic that Gaston has ever been.

There's even dry air in the eye. How does that even happen?


That's supposed to happen. Air flows inward toward the center of a hurricane. Strong convergence in the eye causes the air to sink, drying it out.
Quoting 1054. barbamz:


(Click to enlarge). Aww, what does this straight line mean? Now readings while passing the center?

flight path..

Taco :o)
Quoting 1034. washingtonian115:

Perhaps a brush with the northeast this run??



I've been looking at that for days. It has been 25 years since New England got struck by a hurricane. It is about time, this one in my mind ehhhh probly not the one.
Quoting 1039. Sfloridacat5:

Based on the latest visible satellite it looks like the MLC is about 150-200 miles south of the LLC.


Actually it's only about 1.5 degrees south of the LLC, so roughly 90 nmi or so.
Quoting 1057. TropicalAnalystwx13:


That's supposed to happen. Air flows inward toward the center of a hurricane. Strong convergence in the eye causes the air to sink, drying it out.


Wait. I thought dry air getting to the center of a hurricane disrupted it. Why is it not the case here?
1062. 62901IL
Quoting 1057. TropicalAnalystwx13:


That's supposed to happen. Air flows inward toward the center of a hurricane. Strong convergence in the eye causes the air to sink, drying it out.


Cool, thanks!
Quoting 1028. daddyjames:



Storm is forecast to be well clear of the area by then. And for whatever reason you are going to St. Jude's - I wish you well.


Many thx! Our 14 year old is having a brain tumor removed. It's not agressive. so once it's out, she will recovers and should be well. Just praying the surgery goes well!!! We are so happy that she won't need chemo or radiation.
92L looks like a 99L imposter
1065. mfcmom
Quoting 976. taco2me61:


With all due respect Theirs always "That" chance for a storm to move more westward.
Now on this one, I'm really thinking that Panama City will be the furthest west that it
goes. I really think that's it.... Now I'm not always right either so you might want to
consult someone else on this matter....
Just my opinion.....

Taco :o)
Thanks
GFS no longer develops ex-92L same song and dance
Hurricane watches issued http://www.nhc.noaa.gov/graphics_at4.shtml?5-daynl #contents
1068. GetReal



The best looking swirl on this pic is not the real LLC.
Quoting 1061. AldreteMichael:



Wait. I thought dry air getting to the center of a hurricane disrupted it. Why is it not the case here?


Because the rising air mass eventually cools

edit:
Win 1, at the risk of sounding a bit cynical, there is a third reason why advisories may be a little hard to find: Perhaps an easy comparison would show just how contradictory and wrong the advisories happen to be as a storm progresses. Whether or not there is a disclaimer, how much confidence would you have in their forecasting abilities if you could see them side by side easily? There is not a single person who can confidently predict where TD9 is going to make landfall nor what its intensity will be. And taking Tampa out of the cone may be technically correct, but the odds of the lady near Macdill (very low lying area in Tampa) being affected by flooding seem to be grossly understated. Low tides in South Florida are already looking like high tides.
1071. IDTH
Quoting 1068. GetReal:




The best looking swirl on this pic is not the real LLC.

the MLC.
Quoting 944. mamothmiss:

so being you seem to agree with what i said why did you say ( what is this guy talking about ) for?


I don't believe I said anything about you and "what is this guy talking about" I never said such a thing. Maybe you confused about who said it...what is the post number? I do agree that the cone can and often does change when the forecasted parts not act as they were forecast to and hence lead to errors in landfall location. It could even go right down the middle of the watch area. That's why I said Stay tuned and informed.
Looking at the visible satellite the mlc is well south of the llc. Still decoupled.
1074. Gearsts
Quoting 1066. washingtonian115:

GFS no longer develops ex-92L same song and dance
We don't have 92L?
Seeing some pink showing up in the vorticity of TD 09

Quoting 1060. ecflweatherfan:



Actually it's only about 1.5 degrees south of the LLC, so roughly 90 nmi or so.


Seems like tonight will be the night the low and mid level centers will finally stack. After that it's all steam ahead as it looks to have some very favourable conditions for intensification!
How can you have a hurricane watch w/o even having a TS?
1078. palmpt
Quoting 1063. truecajun:



Many thx! Our 14 year old is having a brain tumor removed. It's not agressive. so once it's out, she will recovers and should be well. Just praying the surgery goes well!!! We are so happy that she won't need chemo or radiation.

God bless your family.
Quoting 1069. win1gamegiantsplease:



Because the rising air mass eventually cools


Quoting 1057. TropicalAnalystwx13:


That's supposed to happen. Air flows inward toward the center of a hurricane. Strong convergence in the eye causes the air to sink, drying it out.


Looking back at post 1057, I read about sinking air.

Is the rising air mass somewhere else?
At landfall in Florida (60 hr)


After landfall, near me (78 hr)


mamothmiss, here is the quote referred to.......wasn't me.

904. mamothmiss
0 +
Quoting 888. Sandcat:


What is this person talking about? Pure denial? Quite strange.
what am i talking about????????? they have had this storm hitting 5 different points from clearwater north already in the past 2 days and they keep shifting it west.. so why cant it keep getting shiffted west towards al/la.
It has nearly caught it. go to earth.nullschool.net and use I and M to go thru the levels. It is the closest it has ever been and is gaining every hour.

Quoting 1073. Bucsboltsfan:

Looking at the visible satellite the mlc is well south of the llc. Still decoupled.
1083. CW7859
While TD9 is interesting because it's closer to home I'm surprised no one seems to realize how impressive Gaston is. Gaston seems to have the characteristics of an Annular Hurricane which is kinda rare.

Gaston:



Annular Hurricane Daniel of 2006



Considering the Atlantic has been dead for years when it comes to powerful hurricanes, it's nice to finally see something like Gaston.
1084. barbamz
Earlier this morning, but still very beautiful (it has just been released on Twitter):
Lisa Bucci %u200F@lbucci45 13 Min.Vor 13 Minuten
Time lapse during #sunrise as we exited #TD9. @NHC_Atlantic forecasts it to become a tropical storm soon... #NOAA43
1085. Patrap

🌅 🌎 🌉 🌊 🎑
1086. IDTH
Quoting 1075. WeatherkidJoe2323:

Seeing some pink showing up in the vorticity of TD 09



MLC is still not aligned yet. I have a feeling as soon as it does this system could really take off.
1087. bwi
Good evening everyone. I'm really impressed with how much surface area little TD nine is affecting surface winds on.

North and NNW! winds way out west north of the bay of Campeche at this buoy.
South and SSW! winds way down south at the bouy in south of the Yucatan channel

If TD9 ever gets all the surface inflow piping straight upward in one column, and vented away at the top, watch the bleep out!
Quoting 1020. mojofearless:



Welcome to the blog, my Louisiana brother. I understand you. You're writing like you speak. That's all. And nobody needs to get on their high horse if someone can't spell something perfectly. It means that they've had to teach themselves, and that is no easy task. So don't let people get you down. You have my welcome and my respect.
I am right there with you, concerned about it shifting track. Just get ready for the worst and hope for the best. It's all we can do.


I'm not so worried....trough moving in along with NE upper level winds effectively blocks out LA from a direct hit. Worst case scenario, a passing whiff of mouth of Mississippi River towards just E of Mobile Bay. More likely, NHC predicted track towards Big Bend/Appalacicola (sp?) then crossing FL/ S GA towards Atlantic.
Hey Yall; dealt with plumbing issues this PM and just checked the track for TD9; headed my way to the Big Bend Coast; serves me right. Hopefully, it will not be able to stack up much and intensify beyond a Cat 1 at land fall. The biggest issue on our coast is coastal surge and all the businesses, homes, and roads (hwy 98) along the coast. Lots of marine interests up here and 98 routinely washes out between St. Marks and Apalachicola. Hoping for the best and the only other worry, inland, is for a minimal rain shield out ahead of the storm before TS winds move inland.

When the big oaks and trees soak up, a 40 mph gust can bring many of them down on homes and cars.

Will keep you posted on conditions up her and between Tallahassee and Quincy to our West over the next few days; I am in Tally for the am tomorrow and then working in Quincy for the rest of the week.

1090. ackee
Quoting 1021. unknowncomic:

  • Don't think 92L going OTS too quickly.

I would be surprised if 92L track futher west into carribbean with those monster High pressure both GFS and Euro showing still don't see how weak system base on both runs moves out of the North East carribbean
1091. IDTH
Quoting 1083. CW7859:

While TD9 is interesting because it's closer to home I'm surprised no one seems to realize how impressive Gaston is. Gaston seems to have the characteristics of an Annular Hurricane which is kinda rare.

Gaston:



Annular Hurricane Daniel of 2006



Considering the Atlantic has been dead for years when it comes to powerful hurricanes, it's nice to finally see something like Gaston.

Gaston is absolutely gorgeous!
Dr. Knabb just said on the weather channel he doesn't think this has a chance at all of becoming a major hurricane. Says hurricane is certainly possible.
Quoting 1076. Envoirment:



Seems like tonight will be the night the low and mid level centers will finally stack. After that it's all steam ahead as it looks to have some very favourable conditions for intensification!


Hard to say at this point. It's possible, but that is one thing this system has struggled with during its whole trip, between the decoupling and the dry air. You could be right. It's just hard to predict those sorts of nuances.
Quoting 1077. Autistic2:

How can you have a hurricane watch w/o even having a TS?


Based on forecast of potential. Watches get issued 36 hours out and warnings 24 hours out.
Quoting 1063. truecajun:



Many thx! Our 14 year old is having a brain tumor removed. It's not agressive. so once it's out, she will recovers and should be well. Just praying the surgery goes well!!! We are so happy that she won't need chemo or radiation.
Best of luck. Saying a prayer for y'all.
Quoting 1083. CW7859:

While TD9 is interesting because it's closer to home I'm surprised no one seems to realize how impressive Gaston is. Gaston seems to have the characteristics of an Annular Hurricane which is kinda rare.

Gaston:



Annular Hurricane Daniel of 2006



Considering the Atlantic has been dead for years when it comes to powerful hurricanes, it's nice to finally see something like Gaston.


Given his name, it's not surprising that Gaston is out there showing off and practically yelling "Look at me! Look at me! Who cares about that little blob, look at MEEEEE!" :)
1097. IDTH

1098. CW7859
Quoting 1077. Autistic2:

How can you have a hurricane watch w/o even having a TS?


Watch means hurricane conditions are POSSIBLE within 48 hours. A lot can happen with TD9 in 2 days time, and that is what the NHC is banking on. 40mph TS to 75mph hurricane is not that far apart, conditions can develop quickly for a strengthening storm.
Post 1068. Thank you for letting me know that, because I was super confused when looking at the plot location from nhc. Can you tell me why it's not the true llc. From a Long long time lurker with still no real weather knowledge.
Quoting 605. TropicalAnalystwx13:

Gaston is the best-looking hurricane in the Atlantic since 2011's Ophelia.


There where also Joaquin thus
So if a hurricane was going over, say, Hawaii, and one of Hawaii's volcanoes suddenly erupted, would the hurricane be immediately destroyed?
Quoting 1083. CW7859:

While TD9 is interesting because it's closer to home I'm surprised no one seems to realize how impressive Gaston is. Gaston seems to have the characteristics of an Annular Hurricane which is kinda rare.

Gaston:




Gaston has an oval shape.. kind of weird. Aren't annular hurricanes circular?
Quoting 1082. SayWhatNHC33:

It has nearly caught it. go to earth.nullschool.net and use I and M to go thru the levels. It is the closest it has ever been and is gaining every hour.




When you look at the visible satellite imagery, that MLC is in no hurry to go anywhere. It is literally stationary.
1104. beell
Quoting 1068. GetReal:




The best looking swirl on this pic is not the real LLC.


That's not an eye, that's an ear!
Quoting 1063. truecajun:



Many thx! Our 14 year old is having a brain tumor removed. It's not agressive. so once it's out, she will recovers and should be well. Just praying the surgery goes well!!! We are so happy that she won't need chemo or radiation.


Hope and prayers all goes well!
Wunderground apparently doesn't like the .gif files from ready.noaa.gov? The url is shorter and much less complicated than those from tropicaltidbits.

[Link]

At least they haven't been updated to show the 18z run yet
1107. Patrap
Gaston is not annular..as per ADT.

Hurricane 07L

UW-CIMSS Automated Satellite-Based
Advanced Dvorak Technique (ADT)
Version 8.2.1
Tropical Cyclone Intensity Estimation Algorithm

Current Intensity Analysis



UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 30 AUG 2016 Time : 211500 UTC
Lat : 32:28:05 N Lon : 51:47:50 W


CI# /Pressure/ Vmax
5.5 / 957.2mb/102.0kt


Final T# Adj T# Raw T#
5.5 5.8 5.8

Estimated radius of max. wind based on IR : 45 km

Center Temp : +15.3C Cloud Region Temp : -66.4C

Scene Type : LARGE EYE

Positioning Method : SPIRAL ANALYSIS

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : CKZ Method

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 110km
- Environmental MSLP : 1016mb

Satellite Name : GOES13
Satellite Viewing Angle : 45.3 degrees

********************************************




1108. ackee
3 area in the USA areas bracing for tropical weather the Big Island of Hawaii being the most serious under a Hurricane warning stay can't recall seeing something like this
If the storm is moving and the MLC has slowly gotten closer... how exactly is it stationary?


Quoting 1103. ecflweatherfan:



When you look at the visible satellite imagery, that MLC is in no hurry to go anywhere. It is literally stationary.
1110. Patrap



Works fine as you have to remove the s from https.
Quoting 1063. truecajun:



Many thx! Our 14 year old is having a brain tumor removed. It's not agressive. so once it's out, she will recovers and should be well. Just praying the surgery goes well!!! We are so happy that she won't need chemo or radiation.


Well I for one could care less about hurricanes at this moment. God's blessings to your daughter And your family. Speedy recovery, and a bright future!
That is one big eye
1113. CW7859
Quoting 1094. PintailKiller:



Based on forecast of potential. Watches get issued 36 hours out and warnings 24 hours out.


Just for the sake of having the correct information out there for the public, watches are issued 48 hours out and warnings are 36 hours out.

Per NHC:

Link
Quoting 1079. AldreteMichael:



Quoting 1057. TropicalAnalystwx13:


That's supposed to happen. Air flows inward toward the center of a hurricane. Strong convergence in the eye causes the air to sink, drying it out.


Looking back at post 1057, I read about sinking air.

Is the rising air mass somewhere else?

Large-scale dry air does hurt disturbances and tropical cyclones because it hinders the formation of convection which otherwise helps to consolidate circulations, lower surface pressures, increase winds, etc. Dry air in the eye is localized--not related to the overall environment--as a result of air flow toward the center and the rising air in the eyewall that sinks in the center. Overall, hurricanes are very moist.
Quoting 1106. win1gamegiantsplease:

Wunderground apparently doesn't like the .gif files from ready.noaa.gov? The url is shorter and much less complicated than those from tropicaltidbits.

[Link]

At least they haven't been updated to show the 18z run yet


WU doesn't like any image that has an "s" in https: needs to be http:
1116. barbamz
Quoting 1101. AldreteMichael:

So if a hurricane was going over, say, Hawaii, and one of Hawaii's volcanoes suddenly erupted, would the hurricane be immediately destroyed?

I guess the hurricane would be disrupted anyway if it dares to take up with those huge volcanoes on Big Island, even if they don't erupt: Mauna Kea 13,802 ft and Mauna Loa 13,680 ft.
1117. Gearsts
About to collapse.
Quoting 1037. TropicalAnalystwx13:

"95kt"



Beautiful annular storm, too. Rare to have two at once (Lester and Gaston).
1119. Patrap
Storm Relative 1 km Geostationary Visible Imagery

Click image for loop

Checking in from Jacksonville, Florida... looks like exciting times ahead for us in next day or so.
Quoting 1079. AldreteMichael:



Quoting 1057. TropicalAnalystwx13:


That's supposed to happen. Air flows inward toward the center of a hurricane. Strong convergence in the eye causes the air to sink, drying it out.


Looking back at post 1057, I read about sinking air.

Is the rising air mass somewhere else?


The warm air rising from the ocean surface is what builds convection (convergence), so when dust/dry air is getting into a cyclone and hampering its intensity, that's because sinking air disrupts this convection. That's not what's going on in the eye.

As for the volcano bit, if we're referring to the Big Island, it will get destroyed, because 13,000' Mauna Loa and Mauna Kea will tear it to bits.
1122. Patrap
Quoting 1109. SayWhatNHC33:

If the storm is moving and the MLC has slowly gotten closer... how exactly is it stationary?





From 1515Z-2215Z, the MLC has been in the same spot roughly 22.8N 87W. Loop the satellite image and look at that spot.
1124. Houdude
Sure looks from visible sat that the center of 09 is at 23N, 87 W, about a degree and a half south of the NHC fix.
JeffMasters has created a new entry.
Quoting 1102. Sharkicane:



Gaston has an oval shape.. kind of weird. Aren't annular hurricanes circular?

More or less, but Gaston is also at 33N, which impacts the shape a bit when viewed two-dimensionally.
Based on recent Satellite images the MLC and LLC are almost aligned
1128. CW7859
Quoting 1107. Patrap:

Gaston is not annular..as per ADT.





I wasn't 100% sure, but still very impressive none the less. Just wanted to show Gaston a little love :)
Quoting 1115. nrtiwlnvragn:



WU doesn't like any image that has an "s" in https: needs to be http:


Thanks, Pat as well
Quoting 1124. Houdude:

Sure looks from visible sat that the center of 09 is at 23N, 87 W, about a degree and a half south of the NHC fix.


That's the mid level center (MLC).
Quoting 1107. Patrap:

Gaston is not annular..as per ADT.

Hurricane 07L

UW-CIMSS Automated Satellite-Based
Advanced Dvorak Technique (ADT)
Version 8.2.1
Tropical Cyclone Intensity Estimation Algorithm

Current Intensity Analysis



UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 30 AUG 2016 Time : 211500 UTC
Lat : 32:28:05 N Lon : 51:47:50 W


CI# /Pressure/ Vmax
5.5 / 957.2mb/102.0kt


Final T# Adj T# Raw T#
5.5 5.8 5.8

Estimated radius of max. wind based on IR : 45 km

Center Temp : +15.3C Cloud Region Temp : -66.4C

Scene Type : LARGE EYE

Positioning Method : SPIRAL ANALYSIS

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : CKZ Method

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 110km
- Environmental MSLP : 1016mb

Satellite Name : GOES13
Satellite Viewing Angle : 45.3 degrees

********************************************







Gaston a major again... incredible. Haven't seen a CV storm quite like him in years. And by that I mean not tiny Danny. This guy is a powerhouse. Any chance he could pull a Faith with the structure he has?
Quoting 1089. weathermanwannabe:

Hey Yall; dealt with plumbing issues this PM and just checked the track for TD9; headed my way to the Big Bend Coast; serves me right. Hopefully, it will not be able to stack up much and intensify beyond a Cat 1 at land fall. The biggest issue on our coast is coastal surge and all the businesses, homes, and roads (hwy 98) along the coast. Lots of marine interests up here and 98 routinely washes out between St. Marks and Apalachicola. Hoping for the best and the only other worry, inland, is for a minimal rain shield out ahead of the storm before TS winds move inland.

When the big oaks and trees soak up, a 40 mph gust can bring many of them down on homes and cars.

Will keep you posted on conditions up her and between Tallahassee and Quincy to our West over the next few days; I am in Tally for the am tomorrow and then working in Quincy for the rest of the week.




Be safe there for sure! I am in Jacksonville and still not 100% sure what we will be looking at here and I have big canopy oaks all around my house luckily had them trimmed nicely a few years ago here's hoping for the best.
1133. guygee
I usually save the sw ir for night-time viewing, but I thought folks might find this interesting: MLC drying out or dying-out/reforming?

Oh, how I wish my ignore user button.
Quoting 1127. WeatherkidJoe2323:
Based on recent Satellite images the MLC and LLC are almost aligned

How close would you estimate?
1136. Patrap
Quoting 1125. WunderAlertBot:

JeffMasters has created a new entry.
1137. Patrap
Radar floater image

1138. IKE
TD9 looking better.
HurricaneTracker App ‏@hurrtrackerapp 16m
Wow, it’s been 1061 days since the last Hurricane Watch was issued for the NW FL coast.
With the MLC and LLC being so far apart, I wonder if we will see a repeat of Hurricane Earl from 1998? (Only with landfall about 75-100 miles to the east)
1141. vis0

Quoting 911. AtHomeInTX:



I got Aloha today. 😊
It must've been a test as a few months ago i had over 40 languages saying hi,    HA! more hi's that a blocking pattern , HA! 
3 times more Hi's than actual members that can see my comments   ...i figured wundergroumnd had some sort of short circuit with the UN climate pages.

 Well it looks like serious ramping up is happening time for me to cut the zillies,  serious flooding could be in the cards over the next week due to TS/Hurr,  don't forget Hawaii

1142. tom1516
Quoting 897. daddyjames:



No, its East Central Florida.
Their not saying Indian river, it's Indian pass. About half way between Tallahassee and Panama City Beach.
helloo from the north ! just wondering where to locate model runs on wunderground now . stormy season is coming and I like to keep track ! thanks
Gaston looks very impressive does anyone else think it's a lot higher than 110mph?
Quoting 1131. LostTomorrows:



Gaston a major again... incredible. Haven't seen a CV storm quite like him in years. And by that I mean not tiny Danny. This guy is a powerhouse. Any chance he could pull a Faith with the structure he has?

This might be a minor tangent to your question, but to be honest, I have my doubts that even Faith truly "pulled a Faith." Without having seen anything convincing aside from what is currently listed in the Best Track that demonstrates Faith's tropical nature so far to the north and east, I'll remain skeptical. That is one I'm quite interested to see what reanalysis turns up.
Quoting 1142. tom1516:

Their not saying Indian river, it's Indian pass. About half way between Tallahassee and Panama City Beach.


That was my bad, I had asked if Indian River was by Pensacola.........instead of Indian Pass which I found out later was in the panhandle area. I was making up my watch and warning maps on Google, sorry for the bad.
1147. GatorWX
Hashtag not annular. Working. All I got. Be back l8r.
Wet day in South Florida.
Wet day in South Florida.