First Invest of the year peters out; Florida gets soaked

By: Dr. Jeff Masters , 1:00 PM GMT on May 19, 2009

Share this Blog
3
+

A complex weather system is bringing showers and thunderstorms over Florida and the Bahamas, in association with a trough of low pressure. Two 1010 mb surface lows have developed--one over the Florida Keys, near 24N 81W, and the other over the south-central Bahamas, near 23N 77W. This second low was designated Invest 90L by the National Hurricane Center yesterday afternoon, and was the first area of interest so designated this year. At that time, they gave it a 30% chance of developing into a tropical cyclone by Wednesday. However, current satellite imagery shows little organization of the cloud pattern and no signs of a surface circulation, and the region is under high shear of 30 knots. 90L is being absorbed into the larger low over Florida, and is no longer a threat to develop, according to a Special Tropical Weather Outlook issued by NHC.


Figure 1. Current radar-estimated precipitation from the Melbourne radar.

The latest 00Z and 06Z runs of the computer models continue to forecast the intensification of an extratropical low near Florida over the next day. The low should bring heavy rain and possible flooding problems to Florida and the Bahamas this week as it moves west or west-northwest into the Gulf of Mexico. Up to eight inches of rain have already fallen over Florida so far (Figure 1), thanks in most part to a cold front that moved over the state during the past two days. Florida could use the rain--most of South Florida is under extreme drought, and Central Florida is under severe drought. The Lake Okeechobee water level is at 10.58 feet, which is about 3 feet below average. During the past week, the lake fell below the level that triggers water conservation measures for the first time since Tropical Storm Fay filled up the lake in August.

I don't expect development of a tropical or subtropical storm over the next two days, due to high wind shear. However, once the system moves into the Gulf of Mexico later this week, the ECMWF and UKMET models are predicting wind shear will drop enough over the northern Gulf of Mexico to allow some development. The GFS and NOGAPS models portray an unfavorable environment with higher shear. I'll give a 20% chance of this system eventually developing into a tropical or subtropical depression in the next seven days. The storm is expected to come ashore over Louisiana on Saturday (NOGAPS and UKMET models), or Sunday over Texas (ECMWF model). The GFS model dissipates the storm over the southern Gulf.

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: 327 - 277

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26Blog Index

Quoting IKE:
12Z CMC


You know, it's a good job CMC doesn't do newspapers as well.

Imagine what they'd be like with swine flu?
Member Since: Posts: Comments:
326. IKE
12Z CMC
Member Since: Posts: Comments:
AH c'mon OSSGSS...lol!
Member Since: Posts: Comments:
Quoting Ossqss:
I think we need a pre-invest-interruptus, until the appropriate agency calls it out :)


Maybe :) Speaking of agencies, has NHC updated their weather discussion since this morning? I am curious of their take on this "system" right off the west coast of Florida?
Member Since: Posts: Comments:
Quoting Ossqss:
I think we need a pre-invest-interruptus, until the appropriate agency calls it out :)


Yep. Shouldn't call it what it's not. Right now we have a very broad area of disturbed weather.
Member Since: Posts: Comments:
It's really nice to read up on these events of the day. My eye is on the GOM Thursday when pre91L becomes 91L.
Member Since: Posts: Comments:
I think we need a pre-invest-interruptus, until the appropriate agency calls it out :)
Member Since: Posts: Comments:
319. IKE
Quoting TheCaneWhisperer:


Not to mention it comes over from the EPAC.

Current area down in the lower EPAC maybe?


Could be. It's been showing up on the GFS the last few runs.
Member Since: Posts: Comments:
No 91L, but things might get interesting. Looks like that circulation about to come off w coast of FL, S of Tampa Bay, is lower level to me. Supported by vorticity chart. Still a lot of shear, though.

Member Since: Posts: Comments:
Pre-91L is starting to look better organized... I am impressed that approaching the MIN that it is holding together...
Member Since: Posts: Comments:
Quoting MahFL:
jeffs713, there is no "system". You mean there is dry air on the left and moist air on the right ? No surface feature has formed yet. It is all middle and upper related.


By "system", I mean the Low in the middle and upper levels. I know it doesn't have a surface feature yet. The dry air is pretty deep, and that will help prevent anything from popping in my eyes.
Member Since: Posts: Comments:
Quoting clwstmchasr:
Thanks StormW! looks like 91L has the most potential for development and the biggest chance of ruining my memorial day weekend. ahh!

Please provide me with the link that shows 91L. I can't find it.


There is no 91L yet, people need to quit quoting it as that.
Member Since: Posts: Comments:
No 91L yet. Just what we all have been referring to as pre-91L. Just waiting...

Also, here's Storm Ws report:
However, based on my current analysis, the system currently over FL. appears to be a mixture of a mid level, extratropical system, with a possible low level feature trying to show itself just offshore the Naples area. This portion off Naples, should continue to move SW to SSW over the next 36-48 hours. Forecast steering layers maps indicate this will then head on more of a westerly course to eventually NW to NNW in time (around 90-96 hours out). Right now, due to the shallow warm layer in the GOMEX (skin temp), waters will have a tendency to cool down. As this area moves westward over the GOMEX, it may encounter warmer SST's. Once this is finished wraping energy in and encounters these waters, we could see some orginization of this system.

I would think this would be our next invest, and hence "91L".
Member Since: Posts: Comments:
Quoting Patrap:




Id bring both,..it could be stormy or Beautiful..



LOL Okay - thanks!
Member Since: Posts: Comments:
what is going on???? there are like 4 blobs out there, one invest and a lot a comments!!!! i am going crazy!!!!!!!!!
Member Since: Posts: Comments:
Quoting hurricanehanna:


Okay Pat, so I'm headed your way on Friday....umbrella or golashes?




Id bring both,..it could be stormy or Beautiful..

Member Since: July 3, 2005 Posts: 426 Comments: 129093
Quoting IKE:
That low may not be tropical now, but it sure looks impressive on satellite.

It's consistent.


Not to mention it comes over from the EPAC.

Current area down in the lower EPAC maybe?
Member Since: Posts: Comments:
The GFSx always keeps it interesting seems.


GOM IR Loop
Member Since: July 3, 2005 Posts: 426 Comments: 129093
Quoting Patrap:
FNMOC WXMAP
FNMOC WXMAP Global Areas (NGP, GFS):


GOM IR loop


Okay Pat, so I'm headed your way on Friday....umbrella or golashes?
Member Since: Posts: Comments:
Quoting clwstmchasr:
Thanks StormW! looks like 91L has the most potential for development and the biggest chance of ruining my memorial day weekend. ahh!

Please provide me with the link that shows 91L. I can't find it.


Uh, is there a 91L ?
Member Since: Posts: Comments:
Quoting clwstmchasr:
Thanks StormW! looks like 91L has the most potential for development and the biggest chance of ruining my memorial day weekend. ahh!

Please provide me with the link that shows 91L. I can't find it.
i dont know it. please show me
Member Since: Posts: Comments:
305. 7544
ok ill post it before pat does lol

Link

chek it out thanks pat
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting SomeRandomTexan:
90L is probably going to be swallowed up into 91l
That sounds about right
Member Since: Posts: Comments:
NICE Update Storm.... Seems so accurate!
Member Since: Posts: Comments:
300. IKE
That low may not be tropical now, but it sure looks impressive on satellite.
Quoting TheCaneWhisperer:
12ZGFS thinks this area will be around for a long time, lol. Oh wait what's that at towards the end of the run?


It's consistent.
Member Since: Posts: Comments:
UNCLASSIFIED
Back
FNMOC WXMAP Model: NOGAPS Area: Atlantic DTG: 2009051912
Member Since: July 3, 2005 Posts: 426 Comments: 129093
90L is probably going to be swallowed up into 91l
Member Since: Posts: Comments:
did the latest GFS run yet? Duh, timing issue. nevermind
Member Since: Posts: Comments:
296. 7544
so as of the post of 287 the low is parked over south fla spining around and will bring in all the blobs to the east that from 90l west over sfla today and tomorow then it moves into the gom where some dev. is possible is that about right
Member Since: Posts: Comments:
NEXRAD Radar
Tampa, Composite Reflectivity Range 124 NMI
Member Since: July 3, 2005 Posts: 426 Comments: 129093
Nice spin off of the south-western tip of Florida. Plenty of convection over the Bahamas.

Link

Member Since: Posts: Comments:
its actually a really nice day right now here in srq...77*F, 20mph breezy,partly sunny a little humid but not to bad 70%......I think I'll go fishing before all that energy/rain forming to my south arrives,BBL.....
Member Since: Posts: Comments:
290. beell
Quoting Seastep:
Any system at any level, located from the panhandle down, should be pulled S according to latest steering. Here's the lower level, click here for the other levels.



At present, yes sir. High pressure north of the system looks to be pretty strong. Modeled at 1031mb at the surface. And it should gradually slide off to the east giving us the westerly drift around the southern edge of the ridge. This part of the forecast has not changed I don't think.
Member Since: Posts: Comments:
289. MahFL
jeffs713, there is no "system". You mean there is dry air on the left and moist air on the right ? No surface feature has formed yet. It is all middle and upper related.
Member Since: Posts: Comments:
FNMOC WXMAP
FNMOC WXMAP Global Areas (NGP, GFS):


GOM IR loop
Member Since: July 3, 2005 Posts: 426 Comments: 129093
022

ABNT20 KNHC 191233

TWOAT

SPECIAL TROPICAL WEATHER OUTLOOK

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL

830 AM EDT TUE MAY 19 2009



FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...



SATELLITE IMAGES AND SURFACE OBSERVATIONS INDICATE THAT THE WEAK

AREA OF LOW PRESSURE LOCATED NEAR THE CENTRAL BAHAMAS IS BECOMING

ABSORBED BY A LARGER NON-TROPICAL LOW CENTERED OVER FLORIDA.

DEVELOPMENT OF THIS SYSTEM NOW APPEARS UNLIKELY...AND THE AIR FORCE

RESERVE HURRICANE HUNTER AIRCRAFT MISSION SCHEDULED FOR TODAY HAS

BEEN CANCELED. IN ADDITION...LITTLE DEVELOPMENT OF THE NON-TROPICAL

LOW OVER FLORIDA IS EXPECTED AS IT MOVES WESTWARD INTO THE GULF OF

MEXICO AT 10 MPH OVER THE NEXT DAY OR TWO. THERE IS A LOW

CHANCE...LESS THAN 30 PERCENT...OF TROPICAL CYCLONE DEVELOPMENT IN

THIS AREA DURING THE NEXT 48 HOURS. THIS WILL BE THE LAST SPECIAL

TROPICAL WEATHER OUTLOOK ISSUED FOR THIS SYSTEM.



$$

FORECASTER BERG
Member Since: July 15, 2006 Posts: 175 Comments: 54858
286. MahFL
weathermanwannabe, there is no surface low. The winds are because of the pressure difference from the trough and the high pressure.
Member Since: Posts: Comments:
One thing a lot of people here seem to be missing is the gigantic mass of dry air along the entire western half of this system. It is very dry air, and dry air has killed more than a few developing systems. I can easily see this system entraining some of that dry air as it tries to develop, and it will lose its window of low shear to do anything. I think this will be a TD at best.. and therefore a great rainmaker for FL.
Member Since: Posts: Comments:
Member Since: July 15, 2006 Posts: 175 Comments: 54858
what are the models saying about 90L?
she has nice deep convection
Member Since: Posts: Comments:
Pennock Ln., Jupiter, Florida (PWS)
Updated: 9 sec ago
Mostly Cloudy
79.0 °F
Mostly Cloudy
Humidity: 73%
Dew Point: 70 °F
Wind: 2.2 mph from the East
Wind Gust: 4.6 mph
Pressure: 29.82 in (Falling)
Heat Index: 81 °F
Visibility: 10.0 miles
UV: 6.6 out of 16
Clouds:
Scattered Clouds 1900 ft
Mostly Cloudy 3000 ft
Mostly Cloudy 4100 ft
(Above Ground Level)
Elevation: 31 ft
Member Since: Posts: Comments:
Quoting StormW:


Shouldn't be any worse than you have at the moment...in fact, if things hold true, coastal winds along NC should begin to slowly diminish sometime tomorrow.

Thanks!
current winds about 15-20 with gusts almost to 30
Member Since: Posts: Comments:
Quoting Seastep:
Any system at any level, located from the panhandle down, should be pulled S according to latest steering. Here's the lower level, click here for the other levels.




And the reason SFL is dry as a bone right now.
Member Since: Posts: Comments:
local pressure down to 1010.5mb here in srq..
Member Since: Posts: Comments:
Thanks StormW! looks like 91L has the most potential for development and the biggest chance of ruining my memorial day weekend. ahh!
Member Since: Posts: Comments:
Quoting weathermanwannabe:


Appreciate the observation; I meant any "tropical" development..It is turning out to be pretty strong low nonetheless, and there are strong winds associated with it, but, I am north of it in Tallahassee and while a circulation is evident, it's a very cool/dry wind and not a lick of any discernable rain..This cold front was a pretty strong one for this time of the year and has left a very dry/cool airmass over the Northern Gulf areas which are feeding right into it...


Yes i agree, It felt like fall in New Orleans this morning and yesterday
Member Since: Posts: Comments:

Viewing: 327 - 277

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26Blog 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.