ATL: TROPICAL DEPRESSION CLAUDETTE (04L)

[Sanibel]

Could have fooled me. If that isn't a system in development it's done a pretty good job of looking like one.

[gatorcane]

Steering suggest NW movement:

[HouTXmetro]

Met's in our region were talking about a Tropical Wave following a TUTT low and headed into South Texas early next week. I don't know if they were talking about the Wave associated with 91L but I don't see any other Wave in which they could be discussing.

[jinftl]

If anything does develop, it is probably heading towards the big easy....the map looks more threatening than it should....most of these models don't show a strong system (or even a developing one in some cases). SHIPS intensity models shows a peak strength of 40mph in 24 hours, and then weakening.

[srainhoutx]

i hear there is a possible high pressure pushing down would that block it and send it west?

I haven't seen or heard anything like that.

Where did you hear that? If you have a link, please post it.

Actually I read it earlier as well. Did not say anything about blocking the system but can see how that can come to conclusion. Came from the NWS out of Key West earlier this evening. Basically said tropical wave exiting by midnight with strong ridge building in the SE US and expanding westward overnight through Sunday. Will see if I can find it.

AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
456 AM EDT SAT AUG 15 2009

.DISCUSSION...
.CURRENTLY...
SHOWERS AND THUNDERSTORMS HAVE BEEN SLOW TO MOVE INTO THE KEYS
COASTAL WATERS DURING THE NIGHT...BUT A LARGE AREA OF CONVECTION IS
PRESENTLY ENTERING THE EASTERN FLORIDA STRAITS. SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS DOT THE REMAINDER OF THE SERVICE AREA.
SKIES ARE MOSTLY CLOUDY ALONG THE KEYS ISLAND CHAIN...WITH
TEMPERATURES HOLDING IN THE MID 80S. WINDS ON LAND ARE FROM THE EAST
TO SOUTHEAST AT 10 TO 15 KNOTS WITH OCCASIONAL HIGHER GUSTS.

SURFACE ANALYSIS DEPICTS THE NORTHERN END OF A TROPICAL WAVE MOVING
WESTWARD THROUGH THE FLORIDA STRAITS...WITH THE MAIN PORTION OF THE
WAVE ALONG 81W IN THE CARIBBEAN SEA. ATLANTIC HIGH PRESSURE EXTENDS
WEST INTO THE SOUTHEASTERN AND MID ATLANTIC STATES. ALOFT...THE KEYS
LIE UNDER DIFFLUENT FLOW BETWEEN THE WESTERN END OF THE SUBTROPICAL
RIDGE...AND AN UPPER LEVEL LOW LOCATED SOUTHWEST OF JAMAICA. MIMIC-
TPW SATELLITE IMAGERY AND GPS-MET IPW DATA BOTH INDICATE PWATS
INCREASING SHARPLY ACROSS THE KEYS OVERNIGHT...WITH VALUES NOW LIKELY
NEAR OR ABOVE 2 INCHES.

.SHORT TERM (TODAY THROUGH MONDAY)...
THE WESTWARD MOVING TROPICAL WAVE NOW ON OUR DOORSTEP WILL BE THE
MAIN WEATHER FEATURE OF INTEREST FOR TODAY INTO THIS EVENING. A STRONG
SUBTROPICAL RIDGE BUILDING WESTWARD FROM THE ATLANTIC INTO THE
SOUTHEASTERN STATES WILL BE THE DOMINANT PLAYER IN OUR WEATHER
THROUGH THE REMAINDER OF THE SHORT TERM PERIOD.

FOR TODAY...EXPECT SHOWERS AND THUNDERSTORMS TO CONTINUE INCREASING
ACROSS THE KEYS AND ADJACENT COASTAL WATERS THIS MORNING...AS DEEP
TROPICAL MOISTURE IMMEDIATELY TO THE EAST OF THE WAVE AXIS SPREADS
INTO OUR AREA. FAVORABLE CONVERGENT LOW LEVEL AND DIFFLUENT UPPER
LEVEL FLOW PATTERNS SHOULD AID CONVECTION AS WELL. SATELLITE AND
MODEL TRENDS SUGGEST THAT THE DEEP MOISTURE WILL BE A BIT SLOWER TO
EXIT OUR AREA...SO HAVE MAINTAINED LIKELY WORDING WITH 70 PERCENT
POPS THROUGHOUT THE DAY.

TONIGHT...THE AFOREMENTIONED SLOWER TREND FOR THE ANTICIPATED
DECREASE IN MOISTURE CALLS FOR POPS TO BE BUMPED UP TO CHANCE FOR
THIS EVENING...FOLLOWED BY SLIGHT CHANCE AFTER MIDNIGHT AS DRIER AIR
CURRENTLY EAST OF ANDROS ISLAND SPREADS WEST INTO THE KEYS.

SUNDAY THROUGH MONDAY...A STRONG SUBTROPICAL RIDGE WILL BUILD INTO
THE SOUTHEASTERN STATES AND THE FLORIDA PENINSULA...PROMOTING
BRISK AND DEEP EASTERLY FLOW ACROSS THE KEYS. WE SHOULD BE WITHIN
A RELATIVELY DRY AND STABLE AIRMASS FOR THIS TIME OF YEAR HOWEVER...
AND WILL CARRY JUST SLIGHT CHANCE POPS.

[Stormcenter]

I don't see whatever this turns out to be heading any fiurther west then Mobile, AL. IMO

If anything does develop, it is probably heading towards the big easy....the map looks more threatening than it should....most of these models don't show a strong system (or even a developing one in some cases). SHIPS intensity models shows a peak strength of 40mph in 24 hours, and then weakening.

[HurricaneRobert]

Met's in our region were talking about a Tropical Wave following a TUTT low and headed into South Texas early next week. I don't know if they were talking about the Wave associated with 91L but I don't see any other Wave in which they could be discussing.

It is the wave, but they said it was pushing showers towards the area. They didn't say it was coming here yet.

[Sanibel]

Winds dropping now. Less gusts.

[wxman57]

Just made a surface plot. The spin on radar is definitely aloft. No evidence of a surface low. Pressures are steady in the area and relatively high (1015mb offshore, 1016-1017mb along FL west coast). No turning on surface obs. Max winds 10-15 kts. I estimate 18 hours offshore at most. MLC could build to surface before then and become a TD.

[Stormcenter]

wxman57 as of now where does the "best bet" for landfall look like?

Just made a surface plot. The spin on radar is definitely aloft. No evidence of a surface low. Pressures are steady in the area and relatively high (1015mb offshore, 1016-1017mb along FL west coast). No turning on surface obs. Max winds 10-15 kts. I estimate 18 hours offshore at most. MLC could build to surface before then and become a TD.

[Sanibel]

Guess it was thunderstorm related in the mid-level bands.

Can't have a surface circulation if that buoy 200 miles west of Captiva is showing an east wind. Unless it was very local and tight near the center.


I think it will drill down. It has energy - trust me.

[jinftl]

Please share that with the folks who think this should be on imminent 'code red' development. Something to keep an eye on...nothing to panic about. Trust me.

Guess it was thunderstorm related in the mid-level bands.

Can't have a surface circulation if that buoy 200 miles west of Captiva is showing an east wind.


I think it will drill down. It has energy - trust me.

[Sanibel]

I think we'll see something tomorrow. We see Q-scats in the Caribbean that miss these things all the time.

[Javlin]

Just made a surface plot. The spin on radar is definitely aloft. No evidence of a surface low. Pressures are steady in the area and relatively high (1015mb offshore, 1016-1017mb along FL west coast). No turning on surface obs. Max winds 10-15 kts. I estimate 18 hours offshore at most. MLC could build to surface before then and become a TD.

That spot looks familiar X

[Aric Dunn]

latest plots surface plots. and my estimate of location .. and there is evidence of broad surface circulation...

extrapolating pressure .. is 1012 to 1013 where the center of broad turning a mid level circ....( not saying they are co-located)
south wind at the ship to the south se winds at land sites with a east wind just south of tampa and a NE wind at the buoy west of the circ.. so there is some broad surface turning that may be more noticeable closer the the convection since the system is small.. and we have no reports in that area so its hard to be for sure. But with as well developed of a mid level circ that we have, it is likely that some surface reflection does exists and depending on how fast it can take shape will be key. also pressure are lower in the vicinity of the deeper convection and mid circ.

[LaBreeze]

I don't see whatever this turns out to be heading any fiurther west then Mobile, AL. IMO

If anything does develop, it is probably heading towards the big easy....the map looks more threatening than it should....most of these models don't show a strong system (or even a developing one in some cases). SHIPS intensity models shows a peak strength of 40mph in 24 hours, and then weakening.

I tend to agree with this idea - no further west than Mobile, or even Pensacola.

[Javlin]

The middle radar(ramidis) Tolkram looks like were I think the center is tring to form at 26N and 83.5W tuuf to tell though just looks more wrapping there.
Hasn't moved much in 4 hrs??

[Aric Dunn]

925 MB vort map ( which is in the 1000ft range)... there is clear low level turning ...

[srainhoutx]

The middle radar(ramidis) Tolkram looks like were I think the center is tring to form at 26N and 83.5W tuuf to tell though just looks more wrapping there.
Hasn't moved much in 4 hrs??

Agree. Has come to crawl. 26.5/83.5 roughly IMHO.

[CYCLONE MIKE]

Steering suggest NW movement:

Isn't that current though. An AFD out of NWS Key West was posted earlier stating that strong high pressure was forecast to build in and expand westward overnight through sunday in the southeast. Maybe that is why 91L is not moving anywhere to quickly right now. Might start getting pushed more westerly later tonight/early this morning.