Tropical depression forming over the Bahamas

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

Share this Blog
0
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 421 - 371

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17Blog Index

421. tropicfreak
2:49 PM GMT on July 22, 2010


Nice features to 98L.
Member Since: September 2, 2006 Posts: 110 Comments: 6874
420. CybrTeddy
2:49 PM GMT on July 22, 2010
Quoting chrisdscane:
some of my sources r saying 45mph at advisory


Your sources are?
Member Since: July 8, 2005 Posts: 259 Comments: 23570
419. ho77yw00d
2:49 PM GMT on July 22, 2010
hahaha so funny!!!! lol...
Member Since: July 3, 2010 Posts: 0 Comments: 427
418. CybrTeddy
2:49 PM GMT on July 22, 2010
Quoting AlexEmmett:

hahaha that would epic and on cnn lol i can just see the title of the story now,
Breaking NEWs: Jeff Masters blog Crashes NOAA SITE


I doubt that would be a news story.
Member Since: July 8, 2005 Posts: 259 Comments: 23570
417. BradentonBrew
2:49 PM GMT on July 22, 2010
Quoting Jeff9641:
I just tracked out the movement right now of 97L and if it stays on this path it will move into Miami/FLL area tomorrow afternoon.



So no Cape Canaveral?
Member Since: June 27, 2009 Posts: 0 Comments: 11
416. Hurricanes101
2:48 PM GMT on July 22, 2010
98L looks decent but it may run out of time before being classified
Member Since: March 10, 2010 Posts: 1 Comments: 7367
415. chrisdscane
2:48 PM GMT on July 22, 2010
some of my sources r saying 45mph at advisory
Member Since: July 21, 2010 Posts: 0 Comments: 1065
414. 69Viking
2:48 PM GMT on July 22, 2010
Quoting gulfbreeze:
If you live in Pensacola or Gulf Breeze you dodn't!!


Us in Navarre and Fort Walton Beach don't forget either, remember we were on the East side of that beast and the Storm Surge was huge. A friend of mine's home in Navarre had 41" of water pass through it destroying the house almost 1/2 mile from the sound! I helped salvage what belongings we could and what a muddy mess. When we walked down the street towards the water we saw nothing but cement slabs where homes use to be, I'll never forget seeing that and wondering if the people evacuated or not.
Member Since: August 25, 2006 Posts: 1 Comments: 3010
413. SWFLCruiser
2:48 PM GMT on July 22, 2010
We're in a marina in Marathon for a little diving (haha); what should we expect from 97L/Bonnie?
Member Since: January 30, 2010 Posts: 0 Comments: 1
412. AlexEmmett
2:48 PM GMT on July 22, 2010
Quoting CybrTeddy:
I seriously think today's the day WU will finally crash the NHC's server with the F5 clicking.

hahaha that would epic and on cnn lol i can just see the title of the story now,
Breaking NEWs: Jeff Masters blog Crashes NOAA SITE
411. brla61
2:48 PM GMT on July 22, 2010
Quoting StormW:


You're welcome!

I don't believe you realize just how important you are to this blog. We appreciate your input and others also but there so many here that I forget who all to list. however, some of us are obsessive. Every am,after reading Masters update & clicking my heels to together repeatedly.I began to chant "i've got to see Storms update" and F5ing like a madwoman...lol
Member Since: June 21, 2010 Posts: 0 Comments: 61
410. stormchic
2:48 PM GMT on July 22, 2010
Quoting StonedCrab:


Absolutely

Okay,well I always get my hurricane supplies in early June. Now I just need to bring in things from outside that can blow around. Thanks!
Member Since: August 22, 2008 Posts: 0 Comments: 30
409. Abacosurf
2:47 PM GMT on July 22, 2010
Quoting tropicfreak:


When floyd moved through the bahamas before it barely missed FL, it weakened a bit but once it left it restrengthened.

I think it was a replacement cycle. only 5 mph decrease.

I was on Great Guana Cay. It was not weak. 150 mph sustained winds for over 12 hours. 2 plus hour eye passage. Gusts recorded to 221 MPH!!!
Member Since: August 28, 2008 Posts: 0 Comments: 293
408. bohonkweatherman
2:47 PM GMT on July 22, 2010
Glad all of these Bay of Campeche storms are going west, can you imagine if they went north or northeast. 98L could have been a major hurricane if it had time which it does not.
Member Since: July 5, 2009 Posts: 0 Comments: 1348
407. CybrTeddy
2:47 PM GMT on July 22, 2010
Quoting MiamiHurricanes09:
If there is no 11 AM EDT advisory this blog will be unbearable.


There will be.. it might be like Dolly with the late advisory as they take a while to get watches and warnings in. They might also be checking to see if this might be Bonnie already.
Member Since: July 8, 2005 Posts: 259 Comments: 23570
406. Eagle101
2:47 PM GMT on July 22, 2010
Quoting ho77yw00d:
... 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?


Good Morning…

As Patrick would say (the voice of reason…), always be prepared during the active season. Have a disaster supply kit (food, water, first aid, NOAA radio, ect.) and listen to official sources…your local emergency management, NWS, and NHC. As long as you are prepared, you will have no worries. Also, make sure you have a way out and cash if you are told to evacuate. Leaving earlier is always better, when advised to do so. I have had friends whom I tried to warn early, and they ended up joining the late thousands who wait until the last minute, and end up riding out the storm/hurricane in their cars on the interstate. Just be prepared. I always prepare as if my survival would depend on my actions alone, assuming no government services are going to be available.

Very Respectfully,

Jon
Member Since: January 7, 2007 Posts: 0 Comments: 40
405. earthlydragonfly
2:47 PM GMT on July 22, 2010
Quoting MiamiHurricanes09:


Man that is really starting to look like a symmetrical storm. banding is looking very strong.
Member Since: July 1, 2005 Posts: 10 Comments: 1683
404. 7544
2:47 PM GMT on July 22, 2010
97l now looks like the symbol of a ts
Member Since: May 6, 2007 Posts: 0 Comments: 6690
403. UpperLevelLOL
2:47 PM GMT on July 22, 2010
Remember when all those fools were comparing this to Katrina? Good times....
Member Since: September 1, 2008 Posts: 0 Comments: 134
402. Dropsonde
2:47 PM GMT on July 22, 2010
Based on where the center appears to me to be (and the NHC may shoot this out from under me in 15 minutes), I think the new thunderstorm is going to blow up right on top of it.
Member Since: August 22, 2006 Posts: 10 Comments: 414
401. MiamiHurricanes09
2:46 PM GMT on July 22, 2010
If there is no 11 AM EDT advisory this blog will be unbearable. LOL, luckily there will be one.
Member Since: September 2, 2009 Posts: 130 Comments: 21091
I seriously think today's the day WU will finally crash the NHC's server with the F5 clicking.
Member Since: July 8, 2005 Posts: 259 Comments: 23570
Jul 22, 2010; 9:35 AM ET Tropoical depression 3 has formed Northwest of Great Inagua near the central Bahamas. A second depression is forming in the Bay of Campeche in the southwest Gulf of Mexico
Member Since: Posts: Comments:
Quoting Hurricanes101:


that had more to do with the fact that Floyd topped out in the Bahamas and basically got so strong it weakened itself


I saw TWC coverage of Floyd on Youtube, and thats what John hope pointed out.
Member Since: September 2, 2006 Posts: 110 Comments: 6874

Tampa Bay area protection shields are only operating at 1/2 capacity due to budgetary cutbacks. So, it is possible TB will feel effects of only 50% of the storm. Unfortunately, the nasty side of the storm.
Member Since: Posts: Comments:
Quoting Jeff9641:


Nam shows weak system and i mean very weak.
Don't look at the NAM for intensity, there are plenty of models for that. The only thing I am looking at the NAM for is where it is taking the moisture.
Member Since: September 2, 2009 Posts: 130 Comments: 21091
Quoting PensacolaDoug:



How true!


I'm under the impression that the Bahamas are not much more than speed bumps.
Member Since: July 25, 2006 Posts: 0 Comments: 551
Quoting stormchic:

Hi Miami,
I live in southern Fl.(Homestead)do you think we will also be under the TS warnings?I enjoy your input on the tropics...thanks! :-)


Absolutely
Member Since: Posts: Comments:
309
Member Since: Posts: Comments:
Quoting IKE:
refresh....refresh....refresh....sip of coffee....refresh...refresh....


LMAO!!! Gotta hand it to you on that one.
Member Since: Posts: Comments:
So did they hit the abort button on the 8am model runs? I still don't seen them and it's nearly 11am.
Member Since: Posts: Comments:
Quoting tropicfreak:


When floyd moved through the bahamas before it barely missed FL, it weakened a bit but once it left it restrengthened.


that had more to do with the fact that Floyd topped out in the Bahamas and basically got so strong it weakened itself
Member Since: March 10, 2010 Posts: 1 Comments: 7367
Quoting hurrkat05:
GOOD OBSERVATION TEDDY I AGREE WITH YOU ON THAT WHAT I DIN'T AGREE WITH YOU GUYS IS THE STRENGTHING PART...YOU WILL HAVE NO MORE THEN A WEAK TROPICAL STORM AT BEST..BONNIE HAS NO CHANCE OF REACHING HURRICANE FORCE IN THE GOM...TOY MANY NEGATIVE FACTORS AHEAD OF HER...

Dude when you repeat the same argument over and over, All you prove is your ignorance in the matter. It looks like you memorized it and now you are just repeating it. Not to mention the fact that you use all caps which either means that you are too lazy to worry about capitalization or you are just loud which is another argument in favor of ignorance. No disrespect intended, but calm down and see what happens.
Member Since: Posts: Comments:
Member Since: September 2, 2009 Posts: 130 Comments: 21091
Quoting IKE:
refresh....refresh....refresh....sip of coffee....refresh...refresh....
No time for coffe duing a refresh....you know that
Member Since: Posts: Comments:
Quoting FLdewey:
The server in Master's closet is getting warm... hope the cat doesn't get curious.

hhahaha so cruel
Quoting hydrus:
97L is in the midst of all those good sized islands. Could this slow the organization?


When floyd moved through the bahamas before it barely missed FL, it weakened a bit but once it left it restrengthened.
Member Since: September 2, 2006 Posts: 110 Comments: 6874
379. IKE
Quoting DestinDome:
Intensity?


Kills it in the eastern GOM.
Member Since: Posts: Comments:
Quoting IKE:
refresh....refresh....refresh....sip of coffee....refresh...refresh....


lmao
Member Since: March 10, 2010 Posts: 1 Comments: 7367
The Bahamas never slow intensification.. the waters around the Bahamas are more shallow which means they are warmer. If anything they get stronger in the Bahamas.
Member Since: July 8, 2005 Posts: 259 Comments: 23570
Quoting Jeff9641:
The latest NAM has shifted north and is calling for S FL to panhandle impact.
The NAM might not do so bad at this point since it isn't forecasting cyclogenesis but rather moisture.
Member Since: September 2, 2009 Posts: 130 Comments: 21091
Quoting hydrus:
97L is in the midst of all those good sized islands. Could this slow the organization?


No way.
Member Since: August 28, 2008 Posts: 0 Comments: 293
Quoting bohonkweatherman:
I would be surprised if we do not have Bonnie by noon today.


then you will not be surprised because the update is at 11am. JK
Member Since: July 1, 2005 Posts: 10 Comments: 1683
372. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #37
SEVERE TROPICAL STORM CHANTHU (T1003)
21:00 PM JST July 22 2010
============================

SUBJECT: Category Two Typhoon Overland South China

At 12:00 PM UTC, Severe Tropical Storm Chanthu (985 hPa) located at 21.7N 109.7E has 10 minute sustained winds of 50 knots with gusts of 70 knots. The cyclone is reported as moving west northwest at 8 knots.

Dvorak Intensity:

Gale Force Winds
================
100 NM from the center in south quadrant
60 NM from the center in north quadrant

Forecast and Intensity
=========================
24 HRS: 22.7N 107.0E - 30 knots (Tropical Depression)
Member Since: Posts: Comments:
Quoting Jeff9641:
The latest NAM has shifted north and is calling for S FL to panhandle impact.
Intensity?
Member Since: Posts: Comments:

Viewing: 421 - 371

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.