Tropical depression forming over the Bahamas

By: Dr. Jeff Masters , 1:29 PM GMT on July 22, 2010

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A tropical wave (Invest 97L) over the eastern Bahama Islands has developed a closed circulation at the surface, and has become a tropical depression or tropical storm. Here is the text of the Special Tropical Weather Outlook from NHC at 8:25am EDT today:

Visible satellite images and observations from the Bahamas indicate that the area of low pressure in the southeastern Bahamas has become better organized and a closed circulation has formed. Advisories on a tropical depression or a tropical storm will be initiated at 11 am EDT...1500 UTC today. This advisory will likely include tropical storm watches and warnings for portions of the Bahamas and southern Florida.

Satellite images of 97L show a modest area of heavy thunderstorms that have slowly increased in intensity and areal coverage this morning. Water vapor satellite loops show a large area of dry air lies to the west of 97L, over Florida. This dry air is associated with a large upper-level low pressure system that is moving west at about the same speed 97L is. The counter-clockwise flow of air around the upper low is bringing about 20 knots of wind shear to 97L. Surface observations in the Bahamas and several nearby ships have shown top winds in 97L of up to 35 mph, so the storm is close to the 40 mph winds needed to be classified as a tropical storm.


Figure 1. Water vapor satellite image showing dry air (brown colors) associated with the upper-level low over Florida. Image credit: NOAA/NESDIS.

Track Forecast for 97L
The storm is in a fairly straightforward steering current environment, and 97L should progress steadily to the west to west-northwest through Saturday. This will bring the storm ashore over the Florida Keys or South Florida on Friday, and into the Gulf of Mexico on Saturday. The latest set of model runs from 2am EDT (6Z) had the advantage of having data from a flight of the NOAA jet last night, so we have higher confidence than usual in the track of 97L over the next two days. The location of 97L's final landfall along the Gulf of Mexico coast has the usual uncertainties for 3 - 4 days, with the various models calling for landfall somewhere between the upper Texas coast and the Florida Panhandle coast. Given the uncertainties, the move halt operations in the Deepwater Horizon blowout recovery effort are probably wise.

Intensity Forecast for 97L
The primary detriment to development of 97L for the next three days will be the presence of the large upper-level low to its west. As long as this low remains in its present location, relative to 97L, it will bring wind shear of about 20 knots and dry air into the storm. This will limit the intensification potential of 97L to no more than about 10 - 20 mph per day. If the upper-level low picks up speed and pulls away from 97L, the storm may be able to intensify at a faster rate. None of the computer models is calling for that to happen, but it is possible. I put the odds of 97L making it to hurricane strength in the Gulf of Mexico at 20%.

98L
An area of disturbed weather (98L) has developed in the Gulf of Mexico's Bay of Campeche. This system is under a low amount of shear, 5 - 10 knots, and may barely have enough time to organize into a tropical depression before making landfall along the Mexican coast a few hundred miles south of the Texas border on Friday.

I'll have an update after NHC releases their 11am advisory package.

Jeff Masters

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Quoting hurrkat05:
WELL STORM I AGREE WITH YOU I BEEN SAYING THAT ALL MORNING TO MUCH DRY AIR AND STRONG WIND SHEAR...BONNIE WILL BE NO MORE THEN A WEAK TROPICAL STORM...


ive said the same thing im not impressed either with the conditions or the way its looking right now im in west kendall,fl and im just putting my umbrella in the car
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... To all my lovely experts and want to be experts (your still good), so in youe best opinon is south florida, such as Fort Myers out of the question for seeing any affects from 97L?
Member Since: July 3, 2010 Posts: 0 Comments: 427
Quoting tea3781:
Do you think that the COC will relocated itself under the deepest convection?


It almost already has!!!
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Quoting BreadandCircuses:




The K storm didn't look all that impressive at this stage in the game either. It was still just a depression as it crossed 80W.


the galveston hurricane of 1900 cross the keys as a "weak tropical wave" :) haha. i bet you could say that about a lot of storms! i remember thinking Katrina wouldnt probably be that bad, and i also remember thinking the same about andrew. They werent cat 5 or anything. and then OMG what happened.
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Quoting Seamule1:
through the FL Keys as a cat 3....

pucker up time for northern Gulf coast...

a cat 5 is NOT out of the realm of possibility.


0.000000001% chance of ever happening.
Member Since: July 8, 2005 Posts: 259 Comments: 23590
264. ATL
Quoting bjdsrq:


The warm sea surface temps from the keys through GOM off SW Florida are *shallow* now. Below 40ft it's unusually cold, only in the mid to upper 70s. Don't know why, just know it is, and that isn't going to show up on satellite imagery. The cold upwelling in the wake should be interesting to watch.

Bonnie shouldn't have much trouble with this unless she stalls out for some odd reason. A TS/weak hurricane can sustain itself fairly easily on low tropical heat content as long as upper levels are favorable.
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For those of you that was on yesterday...remember me posting to watch what happens when 97L moves a little further West into those warmer waters....also, the lifting of the ULL helped also...but, Bonnie just hit warmer waters also.
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Stop yelling at me! :-)
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Quoting StonedCrab:
Why do they still have the 2am maps posted here for 97L?
Isn't there an 8am available?

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Do you think that the COC will relocated itself under the deepest convection?
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Quoting BreadandCircuses:




The K storm didn't look all that impressive at this stage in the game either. It was just named a depression as it crossed 80W.

How about we just start comparing every single storm that forms within 5 degrees of that area?
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Quoting southernbell72:
we are not katrina casters, we are just worried , do u live in new orleans , or even near it , because i do , and if u didnt go through what we went through , u have no right to judge us of our worries on this storm . katrina is a storm that none of us will ever forget . that memory will be with us for a very long time , and with every storm that threatens the gulf , yes it does throw panic into alot of ppl , so just bare with us ok , dont be rude, ty and god bless


Maybe if the non-fla residents would lay off the fla residents all would be good. I am sure you have heard of Andrew and Charley:?
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257. MahFL
The oil spill in China happened days ago, just US news covers the rest of the world very badly.
Member Since: June 9, 2004 Posts: 0 Comments: 3309
Quoting Seamule1:
through the FL Keys as a cat 3....

pucker up time for northern Gulf coast...

a cat 5 is NOT out of the realm of possibility.



Maybe la-tx border to MS????????
Member Since: July 8, 2010 Posts: 0 Comments: 345
Why do they still have the 2am maps posted here for 97L?
Isn't there an 8am available?
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Quoting southernbell72:
we are not katrina casters, we are just worried , do u live in new orleans , or even near it , because i do , and if u didnt go through what we went through , u have no right to judge us of our worries on this storm . katrina is a storm that none of us will ever forget . that memory will be with us for a very long time , and with every storm that threatens the gulf , yes it does throw panic into alot of ppl , so just bare with us ok , dont be rude, ty and god bless


AMEN!!
Member Since: September 2, 2006 Posts: 110 Comments: 6874
Quoting largeeyes:
Wonder if this ridge is gonna protect us in the the Presslina's all summer...
I have said this for decades. The pressalina,s are never safe. If its not one thing, its another, if its not that, its something else, whether it be tornadoes, flooding, mid-latitude cyclones or hurricanes. Never safe.
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Good Morning StormW,

Do you see any weakness in the ridge that seems to be protecting florida that may cause a more northerly turn? Also, how would the strength of the storm affect the projected path?
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YOU know the most accurate it seems so far has been the CMC model which we all was laughing at a couple years back and even last year...funny how things change.
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Good morning.

Wow! 97L is a TD now.
Member Since: August 9, 2009 Posts: 10 Comments: 4902
Quoting reedzone:
Yes, I know it's not August, but look at the SSTs, they are hot! Bath water basically.. That and you have an established anticyclone over the system. Fact is, if you wanna believe it or not, it's up to you, but this could ramp up quicker and stronger then what was previously thought.
Yes, it already has! Stay tuned.
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Quoting whs2012:
Oil Spill in China now?!!
Yes, read that yesterday. Oil like disease or weather knows no borders.
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So now with the ULL moving out will the southern side of the ULL serve to pump additional moisture into 97/TD/Bonnie?

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Quoting btwntx08:
hurrkat is just a painful liar ull is moving away faster and td3 is very slow he better make more crow ready hurrkat


Agreed. She is the banned Stormkat.
Member Since: September 2, 2006 Posts: 110 Comments: 6874
243. 7544
wow looks like a ts in the last rainbow loop getting a good tight round look to it and pulling in new conv from the little blob to the se here she comes folks this will be a interesting 24 hours ahead just before it reaches so fla
Member Since: May 6, 2007 Posts: 0 Comments: 6693
Yes, I know it's not August, but look at the SSTs, they are hot! Bath water basically.. That and you have an established anticyclone over the system. Fact is, if you wanna believe it or not, it's up to you, but this could ramp up quicker and stronger then what was previously thought.
Member Since: July 1, 2008 Posts: 13 Comments: 7340
Quoting reedzone:


It's starting to have that appearance that "K" had when she became a TD. Remember "K" developed next to an ULL to.. Not saying it's going to happen the same way, but if it slows down or the ULL speeds up, with those warm sea surface temps, we could have a major problem in the Gulf.


The warm sea surface temps from the keys through GOM off SW Florida are *shallow* now. Below 40ft it's unusually cold, only in the mid to upper 70s. Don't know why, just know it is, and that isn't going to show up on satellite imagery. The cold upwelling in the wake should be interesting to watch.
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Quoting Jeff9641:
Local met said the stronger it gets the north it will come. A weak system goes south. Boy if this keeps building north then the models will be in uproar.


That would be correct Jeff as i just posted. Not too far North.....even a Cat 5 would go any further north than West Palm Beach if that even....because of the Ridge!
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Quoting Jeff9641:
I got news for you guys the COC continues to build north based Drakeon vis view he posted. I've been noticing this for a while now.


While there is a notherly component to it, WNW is not the same as N.
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Quoting jasoniscoolman2010x:
thanks for the update ..


Look at what we have jason a TD, guess the ULL didn't suck the life out of 97L (now 03L)
Member Since: September 2, 2006 Posts: 110 Comments: 6874
we are not katrina casters, we are just worried , do u live in new orleans , or even near it , because i do , and if u didnt go through what we went through , u have no right to judge us of our worries on this storm . katrina is a storm that none of us will ever forget . that memory will be with us for a very long time , and with every storm that threatens the gulf , yes it does throw panic into alot of ppl , so just bare with us ok , dont be rude, ty and god bless
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Not sure what to think bout td3
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Better get off what ever you on. lol Am in Key Wesst.
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Wait is everyone on here having on ignore?? Or are they just not responding.
Member Since: September 2, 2006 Posts: 110 Comments: 6874
Quoting Drakoen:
Looks like TD3 has building some convection in its northwestern quadrant. Also looks to have slowed down some.
GOES satellite animation

I just hope you are wrong, If Bonnie to be slows down the effectes of the ULL over the GOMEX would be less severe. Perhaps even to the point in which it could strenghten significantly. Worst case scenario, ULL in GOMEX speeds up and Bonnie to be slows down. Looking at the models I dont see that happenng, but they tend to change so much that I just don't know. Comments anyone?
Member Since: August 1, 2007 Posts: 0 Comments: 167
Quoting BreadandCircuses:


The track looks to be almost identical at this point. Of course, at this point they were forecating Rita to hit south of Galveston. Rita had already been a TS for awhile at this point as well.

and it was also 2 months later in the year.
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Quoting Jeff9641:
Local met said the stronger it gets the north it will come. A weak system goes south. Boy if this keeps building north then the models will be in uproar.
Apparently he doesn't think that the ridge to the north isn't too strong, still looks strong to me on steering though.
Member Since: September 2, 2009 Posts: 130 Comments: 21091
I now believe we have a better than 50% chance Bonnie becoming a Hurricane just before South Florida......and who knows what it will become in the GOM .....OH BOY!
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Quoting Hurricanes101:


97L is well organized now, it needs to fill in the west side, but for a TD/weak TS it is well organized


ya but im still not impressed its "heart" (coc) is very vunerable right now
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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