First Invest of the year peters out; Florida gets soaked

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

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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

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1177. Patrap
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
126 AM EDT WED MAY 20 2009

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

* TORNADO WARNING FOR...
EAST CENTRAL LAKE COUNTY IN FLORIDA...
THIS INCLUDES THE CITY OF CASSIA...
Member Since: July 3, 2005 Posts: 423 Comments: 127874
Good evening everyone from Louisiana! Wow! Florida is definitely getting some much needed rain! I am still curious to know whether that low is gonna develop...no one can tell for sure...
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Tornado possible in Deltona, FL largest city in Volusia County.
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South Florida Water Management District Radar Image


South Florida Water Management District Radar/Satellite Image Overlay


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Ike,
Now you know what might be coming to the rest of the Gulf a nasty system.
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Good Morning,
To recap watching spiral bands moving in off East FL Coast producing brief tornadoes and wind damage in Volusia/Seminole/Brevard County.
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thanks. Got my weather radio on, as always! Rain and wind are definitely picking up.
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Quoting animalrsq:
Does anyone know if the winds/rotation hitting the east coast now will be sustained as it moves across the state (I-75, 50 miles west of orlando)?


Probably not the friction of the land should weaken those cells but you could get some heavy rains and straightline wind damage.
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Does anyone know if the winds/rotation hitting the east coast now will be sustained as it moves across the state (I-75, 50 miles west of orlando)?
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Tom Terry doing a great job on WFTV Channel 9, he is sharp Met.
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1166. RevInFL
Here is a link to a good radar shot for those of us in East Central Florida....Looks like we might get a a little break in while.


Link
Member Since: September 6, 2008 Posts: 0 Comments: 163
hey everyone, I don't think 90l is quiet threw yet
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nite taz
Member Since: August 30, 2007 Posts: 0 Comments: 1837
just looked at the dry air issue.. so low chance for Ana to form.. but can't say it won't happen, just a wait and see issue.
Member Since: July 1, 2008 Posts: 13 Comments: 7365
I thought that dry air didn't really inhibit a STD from forming... maybe I am misinformed..lol I probably am... but who knows...

Thanks for keeping me posted.
Member Since: August 30, 2007 Posts: 0 Comments: 1837
Quoting reedzone:
http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8shr.html

Shear is dropping fast.. 10-20 knots getting near the center of the storm.. I think if this continues, 91L will be tagged shortly, possibly Ana in 2 days.. this is IF the wind shear continues it's decrease and the low takes on some subtropical characteristics.




i have too go with redzone with this one i think this will be 91L may be a STS



night all
Member Since: May 21, 2006 Posts: 5091 Comments: 114965
Quoting SomeRandomTexan:
after looking at the 850mb vorticity chart it looks like the llc is strenghting and becoming a smaller unified area instead of an elongated one... am I seeing this right?


Yes, low wind shear is moving into that circulation and might allow some tropical characteristics to form, causing subtropical formation.
Member Since: July 1, 2008 Posts: 13 Comments: 7365
I agree with you on those extended forcast things...haha! Thanks for your thoughts! btw.. aren't you a MET?
Member Since: August 30, 2007 Posts: 0 Comments: 1837
reedzone that wont happen...Dry Air!...Ana isnt in the offering.
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1157. RevInFL
I am in Titusville, we are between bands but there is major roatation with embedded hail coming in in the next 20-30 minutes...
Member Since: September 6, 2008 Posts: 0 Comments: 163
after looking at the 850mb vorticity chart it looks like the llc is strenghting and becoming a smaller unified area instead of an elongated one... am I seeing this right?
Member Since: August 30, 2007 Posts: 0 Comments: 1837
nothing really tropical wise...most exciting thing in all this is the active weather in florida... alot of rain and squalls that is needed here in the state. Tropically speaking, just really a pressure gradient from another weak low that will come ashore in 6-12hrs near the same area.. the cyclonic low will move out into the GOM and be a 1007-1009mb low..but with alot of dry air in the mid and upperlevels. Also anything out more than 3-4 days can not really be accurate. Example is when people post questions on GFS 200 hours out? It's just as a good as a farmer alnamac..lol!
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http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8shr.html

Shear is dropping fast.. 10-20 knots getting near the center of the storm.. I think if this continues, 91L will be tagged shortly, possibly Ana in 2 days.. this is IF the wind shear continues it's decrease and the low takes on some subtropical characteristics.
Member Since: July 1, 2008 Posts: 13 Comments: 7365
anyone out there in east central florida? I am in sanford and we are getting hammered.
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Quoting scottsvb:



nontropical wise...it formed near the straits earlier this evening near 24N and 81W...and its located offshore Naples..but its not tropical.

Now there are many lows along its warmfront .. 1 went onshore about 1 hr ago near the Cape.. another is near Abaco Island.


Tnanks Scott!
If you don't mind sharing, even though it is pure speculation, your thoughts on what this mess will do. Your thoughts and analysis would be greatly appreciated...

I thought I was going crazy seeing all these different swirls...lol
Member Since: August 30, 2007 Posts: 0 Comments: 1837
Quoting CatastrophicDL:

There is a LLC. Link


Yea, a broad one

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1150. Patrap
NEXRAD Radar
Melbourne, Composite Reflectivity Range 124 NMI


The System is Holding its own over the Fla Land Mass as it slowly slides west thru time.
Lotsa energy is going to Swing into the Eastern and Central GOM.
Should be interesting to see how it coalesces tomorrow in those Waters
Member Since: July 3, 2005 Posts: 423 Comments: 127874
Quoting SomeRandomTexan:
don't roast me for asking... but has a LLC formed yet or are we still at a MLC?

There is a LLC. Link
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1142. WeatherStudent 12:39 AM AST on May 20, 2009
Quoting Weather456:


Atlantic Standard Time (AST), the same time as EDT (-4GMT). Only between October and March/April we are an hour ahead of the USA due to DS.


gotvha so its 1;30am?


Its May, time here is 12:45am
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Quoting SomeRandomTexan:
don't roast me for asking... but has a LLC formed yet or are we still at a MLC?



nontropical wise...it formed near the straits earlier this evening near 24N and 81W...and its located offshore Naples..but its not tropical.

Now there are many lows along its warmfront .. 1 went onshore about 1 hr ago near the Cape.. another is near Abaco Island.
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1145. Patrap
Area forecast discussion
National Weather Service New Orleans la
854 PM CDT Tuesday may 19 2009


Long term...
he Gulf disturbance mentioned above pertains to upper level low
that is developing near Florida which was the base of the previous
trough that has been cut off. At this time...still looks like the low will
continue to be cold core and not tropical in nature. GFS and
NAM/dgex just Haven/T had any run to run consistency on the
location...path...strength...etc. Of this feature. The European model (ecmwf) on the
other hand has maintained its solution for at least the last 4 runs.
This model shifts the surface and upper ridge currently impacting the
County Warning Area weather to the east. A weakness in the ridge on the western side
develops later this week from progressively moving trough well to the
north. This will allow the low to change its westerly track to more
northerly towards the central Gulf Coast. The European model (ecmwf) consistently has
problems with excessive output of rainfall...so not so in to going
verbatim on the precipitation. But biggest concern for the later part of
the week and into the weekend will be heavy rainfall. Will have to
continue to monitor but the potential exists for the issuance of a
Flash Flood Watch. In terms of yearly rainfall total...the area is
somewhere in the neighborhood of 5 to 10 inches below normal. Its
possible that localize event totals could reach the lower end of
this value. Still on the lower side of confidence...but a better
idea as to how the event will unfold will come with time.


Meffer

Member Since: July 3, 2005 Posts: 423 Comments: 127874
don't roast me for asking... but has a LLC formed yet or are we still at a MLC?
Member Since: August 30, 2007 Posts: 0 Comments: 1837
widespread damage in casselberry, just pouring here with winds over 40 mph here in sanford
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Shoot! I take a break for a couple of hours and all hell breaks lose in Florida...

Looks like that Low is really trying to moisten up its environment.. just about has the dry air in the GOM pinched off...
Member Since: August 30, 2007 Posts: 0 Comments: 1837
Quoting WeatherStudent:


really/ what tiem is it over tehre? is it dawn?


Atlantic Standard Time (AST), the same time as EDT (-4GMT). Only between October and March/April we are an hour ahead of the USA due to DS.
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TWC just did an update on Vortex2. Is it accurate that they haven't seen any tornados?
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1137. Patrap
Large Scale WV Loop GOM

Member Since: July 3, 2005 Posts: 423 Comments: 127874
1136. RevInFL
There will be no sleep here in Titusville tonight..
Member Since: September 6, 2008 Posts: 0 Comments: 163
1134. Patrap


GOM 60 Hour Surface Current Forecast Model,Loop Current

Member Since: July 3, 2005 Posts: 423 Comments: 127874
Trees down state road 46 mims
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Quoting SavannahStorm:


I'm gonna eat his children.


Or at least bite their ears off!
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1122. SavannahStorm 12:26 AM AST on May 20, 2009

Thank you. You see, I have a program that arhives the marine data from Oceanweather.com but when I was analysing the GOM, that 50 knot station was on the border of the image and so the station's name did show up. Could not determine whether that was a true observastions or error and forgot to check NDBC.

------------------------------------------

WS, no[e, I already slept so I'm here looking at some observastions across the areas affected.
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There is a spin in the atmosphere from a Low in the Gulf 1009 MB CFL is in the NE Quadrant of the storm nasty side to be on tonight. Bad feeling this could happen because of a low crossing the state.
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Quoting Patrap:
Ding Ding,..!


Ga. Coast has that round.





I'm gonna eat his children.

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Um, looks like it's bearing down on us...no wonder it's windy and rainy outside!


Goodnight!
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Quoting Patrap:
Ding Ding,..!


Ga. Coast has that round.




Too funny, Pat! LOL
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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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