Extratropical Depression Lee: Inland N Gulf States

[unome]

a glimmer of hope - one forecaster that's still thinking west ?

http://www.stormw.com/

[sambucol]

Any chance the models will shift more to the west in tonight's model runs?

[unome]

TD13 has made the CIMSS Satellite blog

http://cimss.ssec.wisc.edu/goes/blog/

[singlemom]

Would I assume that the bright spots down south on the Water Vapor imagery would be the possible center reforming or is that the original center?

[unome]

Would I assume that the bright spots down south on the Water Vapor imagery would be the possible center reforming or is that the original center?

neither - it's discussed in the 10 PM:


000
WTNT43 KNHC 020240
TCDAT3

TROPICAL DEPRESSION THIRTEEN DISCUSSION NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL AL132011
1000 PM CDT THU SEP 01 2011

ALTHOUGH THE OVERALL SATELLITE PRESENTATION OF THE DEPRESSION HAS
CHANGED LITTLE THIS EVENING...NEW BANDS OF DEEP CONVECTION HAVE
DEVELOPED TO THE SOUTHEAST OF THE CENTER. SATELLITE
CLASSIFICATIONS AND RECENT BUOY OBSERVATIONS SUPPORT KEEPING THE
INITIAL INTENSITY AT 30 KT. A NOAA HURRICANE HUNTER AIRCRAFT IS
SCHEDULED TO INVESTIGATE THE CYCLONE OVERNIGHT. A SHEAR ANALYSIS
FROM UW-CIMSS SHOWS ABOUT 20 KT OF WESTERLY SHEAR OVER THE
CYCLONE. THIS SHEAR IS FORECAST TO RELAX DURING THE NEXT 12-24
HOURS AS AN UPPER-LEVEL ANTICYCLONE BUILDS OVER THE GULF. THIS IS
EXPECTED TO RESULT IN A FAVORABLE ENVIRONMENT FOR INTENSIFICATION.
HOWEVER...GIVEN THE LARGE SIZE OF THE CIRCULATION...STRENGTHENING
IS EXPECTED TO BE GRADUAL. THE NEW NHC INTENSITY FORECAST IS
NEARLY IDENTICAL TO THE PREVIOUS ADVISORY AND IS A BLEND OF THE
SHIPS/LGEM GUIDANCE.

THE DEPRESSION HAS NOT MOVED MUCH THIS EVENING...AND THE HIGHLY
UNCERTAIN INITIAL MOTION IS 315/2 KT. SINCE THE DEPRESSION IS
STILL IN THE FORMATIVE STAGE...THE CENTER COULD REFORM WITHIN THE
LARGE CIRCULATION DURING THE NEXT 12-24 HOURS. THIS POSSIBILITY
IS SUPPORTED BY THE GFS...WHICH SHOWS THE CENTER REFORMING FARTHER
NORTH WITHIN 24 HOURS. STEERING CURRENTS ARE EXPECTED TO REMAIN
WEAK DURING THE NEXT SEVERAL DAYS AS THE DEPRESSION REMAINS TO THE
SOUTH OF A WEAKENING MID/UPPER LEVEL RIDGE. AS THE RIDGE SLIDES
EASTWARD...IT SHOULD ALLOW THE CYCLONE TO MOVE SLOWLY NORTHWARD...
THEN NORTHEASTWARD. ALTHOUGH THE DYNAMICAL MODELS SHOWS LITTLE
OVERALL MOTION DURING THE NEXT 2-3 DAYS...THERE IS A LARGE SPREAD
IN THE GUIDANCE AND LOWER THAN NORMAL CONFIDENCE IN THE TRACK
FORECAST. THE UPDATED NHC TRACK IS A LITTLE SLOWER AND EAST OF
THE PREVIOUS FORECAST.

THE SLOW MOTION OF THE CYCLONE DURING THE NEXT 5 DAYS IS LIKELY
TO PRODUCE A PROLONGED PERIOD OF TROPICAL STORM CONDITIONS AND
HEAVY RAINFALL OVER PORTIONS OF THE NORTHERN GULF COAST.


FORECAST POSITIONS AND MAX WINDS

INIT 02/0300Z 26.6N 91.5W 30 KT 35 MPH
12H 02/1200Z 27.5N 92.2W 35 KT 40 MPH
24H 03/0000Z 28.0N 92.4W 40 KT 45 MPH
36H 03/1200Z 28.6N 92.4W 45 KT 50 MPH
48H 04/0000Z 29.2N 92.3W 50 KT 60 MPH
72H 05/0000Z 29.7N 92.1W 50 KT 60 MPH...NEAR THE COAST
96H 06/0000Z 30.5N 91.5W 35 KT 40 MPH...INLAND
120H 07/0000Z 31.5N 90.0W 25 KT 30 MPH...INLAND

$$
FORECASTER BROWN

[maroondreams]

So my plan tomorrow morning is to wash my car. Once this happens it will pour like you won't believe.

You can thank me later.

[Belmer]

The link below I found on YouTube regarding Tropical Depression #13. When I watched this video, gave me the Goosebumps (mainly because of the intense music) and quickly reminded me of Allison. Like Frank said on the news cast tonight, this is going to be an Allison storm for much of Louisiana. This storm is broad, (which Allison was) and is already causing rain for much of LA and only the beginning as we have 4-5 days of this. Almost have a sick feeling in my stomach as what LA is really going to get into.
As much as we need rain here in Houston and all across Texas, putting something like TD13, that significant over this area would cause for devastating floods. The ground is like cement right now. Putting that much water on it that quickly wouldn't even have time to soak in, it would quickly run off into the streets and flood many places. I'm just hoping for some good rain bands, and training ones at that.

http://www.youtube.com/watch?v=xDAZqMHS ... ure=colike

[Andrew]

I am thinking the "center" is more around 25N 91W

GFS is very similar to 18z but a little farther west.

http://mag.ncep.noaa.gov/NCOMAGWEB/appc ... mageSize=M

[Andrew]

CMC shows similar to gfs and NAM:

[wxman666]

Good morning y'all! I don't think I've been on since our winter storm, but I am certainly back for this little bugger in the gulf. I have been reading all of your posts, keeping informed. Thanks everyone who has helped out. It's crunch time now. Bring on the caffeine!

[wxman666]

Interesting tidbit from HGX as of shortly after midnight:

MODEL SOUNDINGS DO MOISTEN UP EARLY SATURDAY MORNING AS
THIS TROPICAL SYSTEM MAY WOBBLE CLOSER TO THE UPPER TEXAS COASTLINE
...INCREASING NNE WINDS AND MOISTURE. STAY TUNED!

[randybpt]

Lake Charles thinking this morning Setex get less than an inch from this system. Like the immortal bugs bunny says dat's all folks

[srainhoutx]

TROPICAL DEPRESSION THIRTEEN DISCUSSION NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL132011
400 AM CDT FRI SEP 02 2011

SATELLITE IMAGERY...SURFACE OBSERVATIONS...AND AN EARLIER ASCAT
OVERPASS INDICATE THAT TROPICAL DEPRESSION THIRTEEN HAS A ELONGATED
CENTER OF CIRCULATION...WITH THE ELONGATION CURRENTLY FROM
EAST-NORTHEAST TO WEST-SOUTHWEST. THE ASSOCIATED CONVECTION IS
CURRENTLY POORLY ORGANIZED...ALTHOUGH A STRONG BURST HAS RECENTLY
FORMED NEAR THE EAST-NORTHEASTERN END OF THE CENTER. THE INITIAL
INTENSITY REMAINS 30 KT BASED ON THE ASCAT OVERPASS AND REPORTS
FROM OIL RIGS IN THE NORTHERN GULF. WHILE THERE IS GOOD OUTFLOW
OVER THE EASTERN SEMICIRCLE...AN UPPER-LEVEL TROUGH IS PRESENT OVER
THE WESTERN SIDE OF THE CIRCULATION.

THE DEPRESSION HAS NOT MOVED MUCH DURING THE PAST SEVERAL HOURS...
WITH THE INITIAL MOTION A HIGHLY UNCERTAIN 315/2. THE CYCLONE IS
CURRENTLY IN AN AREA OF LIGHT STEERING CURRENTS SOUTH OF A
MID-LEVEL RIDGE OVER THE MISSISSIPPI VALLEY. THE DYNAMICAL MODELS
FORECAST THIS RIDGE TO MOVE EASTWARD AND WEAKEN AS A DEEP-LAYER
TROUGH MOVES SOUTHEASTWARD INTO THE OHIO VALLEY. THIS EVOLUTION
SHOULD ALLOW THE DEPRESSION TO MOVE SLOWLY NORTHWESTWARD TO
NORTHWARD FOR THE NEXT 24-36 HR...FOLLOWED BY A GRADUAL TURN TOWARD
THE NORTHEAST. MOST OF THE DYNAMICAL MODELS NOW SHOW THIS
SCENARIO...ALTHOUGH THERE REMAINS ENOUGH DISAGREEMENT BETWEEN THEM
TO KEEP THIS A LOW CONFIDENCE FORECAST. THE NEW FORECAST TRACK IS
ADJUSTED SOUTH AND EAST OF THE PREVIOUS FORECAST BASED MAINLY ON
THE INITIAL POSITION...AND LIES CLOSE TO THE VARIOUS CONSENSUS
MODELS FOR THE FIRST THREE DAYS OF THE FORECAST. IT SHOULD BE
NOTED THAT REFORMATIONS OF THE CENTER COULD CAUSE ERRATIC MOTION
AND ADJUSTMENTS TO THE FORECAST TRACK DURING THE NEXT COUPLE OF
DAYS.

THE CURRENT INTERACTION WITH THE UPPER-LEVEL TROUGH IS FORECAST BY
THE DYNAMICAL MODELS TO CONTINUE FOR AT LEAST THE NEXT COUPLE OF
DAYS...RESULTING IN VERTICAL WIND SHEAR CONDITIONS THAT...AT
BEST...WILL BE MARGINALLY FAVORABLE FOR INTENSIFICATION. THIS
INTERACTION...COMBINED WITH THE CURRENT ORGANIZATION OF THE
SYSTEM...SUGGESTS THAT STRENGTHENING SHOULD BE SLOW. THE NEW
INTENSITY FORECAST IS UNCHANGED FROM THE PREVIOUS ADVISORY AND LIES
BETWEEN THE STRONGER SHIPS AND WEAKER LGEM MODELS.

THE LARGE SIZE AND SLOW MOTION OF THE CYCLONE DURING THE NEXT 5 DAYS
IS LIKELY TO PRODUCE A PROLONGED PERIOD OF TROPICAL STORM
CONDITIONS AND HEAVY RAINFALL OVER PORTIONS OF THE NORTHERN GULF
COAST.


FORECAST POSITIONS AND MAX WINDS

INIT 02/0900Z 26.5N 91.7W 30 KT 35 MPH
12H 02/1800Z 27.0N 92.1W 35 KT 40 MPH
24H 03/0600Z 27.6N 92.3W 40 KT 45 MPH
36H 03/1800Z 28.2N 92.2W 45 KT 50 MPH
48H 04/0600Z 28.8N 92.0W 50 KT 60 MPH
72H 05/0600Z 29.5N 91.5W 50 KT 60 MPH...INLAND
96H 06/0600Z 30.5N 90.0W 40 KT 45 MPH...INLAND
120H 07/0600Z 31.5N 88.5W 25 KT 30 MPH...POST-TROP/EXTRATROP

$$
FORECASTER BEVEN

[srainhoutx]

Good morning. While the track of TD 13 has shifted further E into Louisiana, I'd caution folks to not let your guard down just yet. There is a lot of uncertainty regarding the evolution of how things are actually going to develop and some changes as noted by the NHC cannot be ruled out. As the 4:00AM discussion package noted, further shift is the track may well occur and the confidence level remains low...

THIS EVOLUTION
SHOULD ALLOW THE DEPRESSION TO MOVE SLOWLY NORTHWESTWARD TO
NORTHWARD FOR THE NEXT 24-36 HR...FOLLOWED BY A GRADUAL TURN TOWARD
THE NORTHEAST. MOST OF THE DYNAMICAL MODELS NOW SHOW THIS
SCENARIO...ALTHOUGH THERE REMAINS ENOUGH DISAGREEMENT BETWEEN THEM
TO KEEP THIS A LOW CONFIDENCE FORECAST. THE NEW FORECAST TRACK IS
ADJUSTED SOUTH AND EAST OF THE PREVIOUS FORECAST BASED MAINLY ON
THE INITIAL POSITION...AND LIES CLOSE TO THE VARIOUS CONSENSUS
MODELS FOR THE FIRST THREE DAYS OF THE FORECAST. IT SHOULD BE
NOTED THAT REFORMATIONS OF THE CENTER COULD CAUSE ERRATIC MOTION
AND ADJUSTMENTS TO THE FORECAST TRACK DURING THE NEXT COUPLE OF
DAYS.


The 00Z GFS and now the 06Z GFS are beginning to show subtle hints that the evolution of the 850mb vortisity may in fact be shifting back W in time. The 06Z GFS is now suggesting that what remains of td 13 after making landfall in Louisiana is pushed SW back into the Gulf and weak, multi vortex areas of low pressure become elongated off the Upper and Middle Texas Coast through hour 189. This 'hint' started to show in the 00Z GFS and has continued and even become more pronounce with the 06Z GFS. We will begin to see data ingest into the models today from Upper Air data and with further RECON analysis. As has been noted over the past several days, caution is advised as the models or guidance struggle with the synoptic pattern. While rain chances look meager in model world at this time for SE TX, this is a fluid situation and our neighbors to the E in Louisiana will have a full blown mess on their hands regarding extreme heavy rainfall and high rainfall rates of long duration. I urge folks to remain informed and keep up with any changes that may lie ahead over the Holiday week. With a weak, multi vortex system, changes can occur rather quickly and it would not be prudent to dismiss the idea that any threat is over. Coastal flooding, rip currents and extreme fire danger are in the offing for SE TX and should not be taken lightly. Any shift further W in future updates for the NHC could 'catch' some off guard and increase rain chances across the area. Again, prudence suggests that a slowly moving, slow developing storm anywhere in the Western Gulf should warrant attention. As they say, Stay Tuned. It ain't over until it's over, inland and no longer a threat to anyone any further.

[srainhoutx]

The 00Z Euro ensemble mean also are 'hinting' what the 06Z GFS was depicting, for what it's worth...

[srainhoutx]

BULLETIN
TROPICAL DEPRESSION THIRTEEN INTERMEDIATE ADVISORY NUMBER 3A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL132011
700 AM CDT FRI SEP 02 2011

...CENTER OF THE DEPRESSION NEARLY STATIONARY SOUTH OF THE
LOUISIANA COAST...


SUMMARY OF 700 AM CDT...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...27.0N 91.6W
ABOUT 210 MI...340 KM SW OF THE MOUTH OF THE MISSISSIPPI RIVER
ABOUT 250 MI...405 KM SE OF PORT ARTHUR TEXAS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...N OR 360 DEGREES AT 1 MPH...2 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

[jasons2k]

I'm done with TD 13. Time to get the grill, beer, pool, and sunscreen ready for the weekend.....after I go puke.

[srainhoutx]

First visible shot of the morning. We may have a TS if RECON data is correct and the NHC decides to upgrade. We will see...

[kellybell4770]

seems to me that because the models seem to be all over the place (first thing this morning they were ALL pointed toward central LA and just now they are split in half again) we should not completely write off the possibility of rain - everyone knows how unpredictable these things can be! (trying to remain the ever optimist)

[srainhoutx]

RECON has yet to locate a center of circulation. So far data suggests a very large, elongated broad low pressure field (roughly 1006mb) displaced W of the deep convection. The broad surface low extends roughly from about 275 SE of Houston to 280 miles SSW of New Orleans.