ATL: EX-Tropical Depression FIVE - Discussion

[MiamiHurricanes10]

Radar loops from New Orleans earlier today would suggest that ex-05L organized into a tropical cyclone before landfall.

[HURAKAN]

Looks good but winds don't support a tropical cyclone

[MiamiHurricanes10]

:uarrow:

Looks good but winds don't support a tropical cyclone

Structure-wise it matured into a tropical cyclone, however surface observations from around New Orleans never reported winds in excess of 25kt, so you're right...Structure of a TD, winds of a thunderstorm.

[Stormcenter]

That is 100% correct.

It looked like a duck but didn't quack (winds) like one.

:uarrow:

Looks good but winds don't support a tropical cyclone

[Steve]

It's exactly what the remnants of Bonnie did, though Bonnie's winds were a little stronger. This one was buckets of rain (starting to pick up downtown in the city again, but not hard).

This was particularly weird:

>>Ex TD5 is looking better than when it was named.

I think it was the HWRF that indicated lower pressure and slight intensification post landfall (I haven't looked at any pressure readings). NAM actually had a decent looking system from 3-4 days out at the coast, but then it backed off. Then some of the globals wanted to stall a hair at landfall (then one of them, GFS I think) wanted to return the energy back to the Gulf. LMAO. Crazy. It got very close. Zoom of radar shows maybe the twist off of Shell Beach/Ysclosky area possibly headed for New Orleans East and the eastern side of Lake Pontchartrain. But it still looks like a circulation embedded into a broader circulation to me.

[Steve]

http://www.hpc.ncep.noaa.gov/qpf/p120i12.gif

FWIW, QPF 5 day valid 12z has a lot of rain all along the Gulf Coast over toward Panama City Beach. Looking at the 12z NAM and 6Z GFS (12Z only out to 54 hours), it doesn't look like this energy is going to go anywhere anytime soon. 6z GFS looks to strengthen low pressure off the NW FL Coast and move it west again. Not sure if it's progression of the last pattern or if it's just trying to find something to do with the remnant energy, but I doubt any of us on the Gulf Coast will be complaining about the heat for the next several days if this verifies. 12Z obviously a bigger deal than the 6Z, so we'll have to wait and see what happens.

[poof121]

This thing isn't in any hurry to go anywhere... Winds at Shell Beach have been fluctuating between N and NW for the past 8 hours.

http://www.ndbc.noaa.gov/station_page.php?station=SHBL1

[Steve]

Strange though. GFS 12Z is now out much further in time. It's hard to figure out what it's doing, but eventually it regenerates energy off of Mobile Bay and runs it west along the LA Coast over toward Vermillion/Cameron Parishes, then intensifies a bit before turning it due north south of Lake Charles as a reasonably potent system. I guess it's just something to watch for a while to see the pattern evolution.
http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

[Dean4Storms]

We got another circulation now forming south of P'Cola Bch that is showing up on Radar.

http://radar.weather.gov/ridge/radar.ph ... 1&loop=yes

[ColinDelia]

Radar loops from New Orleans earlier today would suggest that ex-05L organized into a tropical cyclone before landfall.

Sure looked good on radar.

TD5 sure was an interesting storm from start to finish.

[Stormcenter]

I'm not sure what is going here but is bears watching as
long as it's close to the water. IMO

http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html

[Steve]

No kidding Dean. Multi-vortex system. Looks like on visible that an eddy or possibly the LLC is still stationary and kind of a naked swirl off of St. Bernard Parish if you zoom in on visible. Rain looks to be tapering off, but if it sits out there, could be another bursting round tonight (I'd put it at about 40/60).

http://www.ssd.noaa.gov/goes/flt/t1/flash-vis.html

[Steve]

Oh and 12Z UKMET joining the chorus of some energy focusing around the Panhandle. These are a couple of maps (though I'm not sure if they'll translate via a link cut and paste - you may have to go to the University of Wyoming or other favorite weather site carrying the UKMET Model). FWIW, the reason I sought that model out was because of it's extrordinary forecast with Hurricane Ivan. Seeing something coming back around again worked once in a completely different scenario, but it was worth a look.

http://weather.uwyo.edu/cgi-bin/model?M ... ne&F2=p06i

http://weather.uwyo.edu/cgi-bin/model?M ... ne&F2=p06i

[cycloneye]

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT THU AUG 12 2010

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

THE BROAD AREA OF LOW PRESSURE ASSOCIATED WITH THE REMNANTS OF
TROPICAL DEPRESSION FIVE HAS MOVED LITTLE DURING THE PAST SEVERAL
HOURS AND REMAINS CENTERED NEAR THE SOUTHEASTERN LOUISIANA COAST.
THIS LOW WILL CONTINUE TO PRODUCE LOCALLY HEAVY RAINS AND
OCCASIONALLY GUSTY WINDS IN SQUALLS AS IT DRIFTS INLAND DURING THE
NEXT DAY OR SO. THERE IS A LOW CHANCE...NEAR 0 PERCENT...OF THIS
SYSTEM REDEVELOPING INTO A TROPICAL CYCLONE DURING THE NEXT 48
HOURS. LOCALIZED FLOODING IS POSSIBLE OVER SOUTHERN LOUISIANA AND
COASTAL MISSISSIPPI...PLEASE REFER TO STATEMENTS FROM LOCAL
NATIONAL WEATHER SERVICE FORECAST OFFICES FOR ADDITIONAL
INFORMATION.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER CANGIALOSI/AVILA

[jasons2k]

:uarrow:

Looks good but winds don't support a tropical cyclone

Is that wind speed or direction? Tropical Cyclones don't have a minimum wind speed criteria. If it is 39mph or greater, it is a TS. Anything less is a TD....and still a TC if is has a closed circulation and sustained deep convection.

[ronjon]

Wow, you can clearly see the LLC spinning in this SAT loop. Doesn't appear to be moving and the heavy convection to the east is being drawn into it.

http://www.rap.ucar.edu/weather/satellite/displaySat.php?region=GOM&itype=vis&size=large&endDate=20100812&endTime=-1&duration=3

[poof121]

Wow, you can clearly see the LLC spinning in this SAT loop. Doesn't appear to be moving and the heavy convection to the east is being drawn into it.

http://www.rap.ucar.edu/weather/satellite/displaySat.php?region=GOM&itype=vis&size=large&endDate=20100812&endTime=-1&duration=3

You can see it on the radar too, seems to be moving NE.

http://radar.weather.gov/radar.php?rid=LIX&product=N0R&overlay=11101111&loop=yes

[Ivanhater]

Need to keep an eye on this with models showing it getting back in the gulf

[Ivanhater]

12z Euro is in line with the GFS sending this back in the Gulf

[poof121]

Wow, you can clearly see the LLC spinning in this SAT loop. Doesn't appear to be moving and the heavy convection to the east is being drawn into it.

http://www.rap.ucar.edu/weather/satellite/displaySat.php?region=GOM&itype=vis&size=large&endDate=20100812&endTime=-1&duration=3

The convection moving towards the LLC is due to easterly shear.