ATL GUSTAV: Tropical Depression - Discussion

[HouTXmetro]

Since we are wobble casting looks like a big Jump West in the last VIS frame of the day.

Link please? Wouldn't surprise me one bit though.

viewtopic.php?f=59&t=102614&p=1802624#p1802624

[Steve Cosby]

Remember, though, that Katrina was weakening at the time of landfall - this one will be deepening - based on everything I've read, that means that two storms of the same category has the weakening storm doing less damage. Sobering.

I disagree. Katrina was huge and powerful and was weakening but the surge was already built up, more like a cat 5 surge.

Yes, no doubt - the point that I kept hearing about Katrina was how much worse it could have been had it not weakened prior to landfall.

[Sanibel]

No doubt Gus is strengthening on approach. Obviously a delayed reaction from the loop current.

[Normandy]

Latest pass didnt find lower pressures. Excellent news.

[Enzo Aquarius]

.AT 700 PM CDT...THE CENTER OF HURRICANE GUSTAV WAS LOCATED NEAR
LATITUDE 26.9 NORTH...LONGITUDE 87.7 WEST OR ABOUT 175 MILES
SOUTH SOUTHEAST OF THE MOUTH OF THE MISSISSIPPI RIVER. THIS
POSITION IS ABOUT 260 MILES SOUTH SOUTHEAST OF NEW ORLEANS.

GUSTAV IS MOVING TOWARD THE NORTHWEST NEAR 17 MPH. THIS GENERAL
MOTION IS EXPECTED TO CONTINUE WITH A DECREASE IN FORWARD SPEED
DURING THE NEXT COUPLE OF DAYS. ON THE FORECAST TRACK...GUSTAV
SHOULD MAKE LANDFALL ON THE NORTHERN GULF COAST ON MONDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 115 MPH WITH HIGHER GUSTS. GUSTAV
IS A CATEGORY THREE HURRICANE ON THE SAFFIR-SIMPSON SCALE. SOME
INTENSIFICATION IS FORECAST TONIGHT...AND GUSTAV IS FORECAST TO BE
A MAJOR HURRICANE UNTIL LANDFALL.

Slowed down just a bit since a few hours ago.

[KWT]

Strong band that went through N.O is strengthening and now extends from LA and through MS, probably a feeder band now I'd guess.

Also main rainshield is just a little bit to the SE of Mobile, should move inland over MS and LA in the next 2hrs, should see a rapid increase in TS force wind speeds soon.

[Dean4Storms]

Doesn't look like there be many feeder bands coming in behind this storm once it gets inland, looks very dry to his south.

[BlackNGoldRules]

Remember, though, that Katrina was weakening at the time of landfall - this one will be deepening - based on everything I've read, that means that two storms of the same category has the weakening storm doing less damage. Sobering.

I disagree. Katrina was huge and powerful and was weakening but the surge was already built up, more like a cat 5 surge.

Yes, no doubt - the point that I kept hearing about Katrina was how much worse it could have been had it not weakened prior to landfall.

And the forecasts had it as a direct hit on NO I believe, and it wobbled to the east right before landfall so NO was actually on the weak side of the eye as well.

[Steve Cosby]

Shear doesn't work that way... it's a difference between winds at different levels. 20 kts of shear is still 20 kts of shear, whether the difference is between an 80 kt wind aloft and a 60 kt wind below, or the difference between a 30 kt wind aloft, and a 10 kt wind below, and so on.

A hurricane moves with the steering flow, which is some weighted average of winds over a depth of the atmosphere, and is different for every system. A hurricane that is stationary and getting sheared from the south, if it started to move north, would experience less shear, not because it was moving "with" the shear, but because the low-level environmental winds have begun to line up more with the upper-level winds, both starting to move the hurricane north, and decreasing the shear at the same time.

I hope that makes sense, and any other met on here who wants to chime in with corrections or additions, please do so..

OK - so it IS more like what we see with supercells (which, as you can tell from my location is a lot higher focus as it is for you I'm sure).

Thanks for the clarification!

[KWT]

Latest pass didnt find lower pressures. Excellent news.

I'm not really surprised to be honest as the eyewall has become a little open on the eastern side yet again, think its back to holding steady again thanks to the big convective bursting.

[RL3AO]

You guys put a little too much into these extrapolated pressures. They can be 4 or 5 mb off.

[KWT]

Doesn't look like there be many feeder bands coming in behind this storm once it gets inland, looks very dry to his south.

Yep thats one blessing, the air is pretty dry behind this system, mind you without air conditioning may leave alot of people, even not near the core without power therefore having sticky conditions.

[Enzo Aquarius]

Tornado warning has just been issued for the Baton Rouge area:

752 PM CDT SUN AUG 31 2008

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A

* TORNADO WARNING FOR...
NORTHWESTERN ASCENSION PARISH IN SOUTHEAST LOUISIANA...
SOUTHERN EAST BATON ROUGE PARISH IN SOUTHEAST LOUISIANA...
THIS INCLUDES THE CITIES OF...OAK HILLS PLACE...BATON ROUGE...
EAST CENTRAL IBERVILLE PARISH IN SOUTHEAST LOUISIANA...
CENTRAL LIVINGSTON PARISH IN SOUTHEAST LOUISIANA...
THIS INCLUDES THE CITY OF DENHAM SPRINGS...
SOUTHEASTERN WEST BATON ROUGE PARISH IN SOUTHEAST LOUISIANA...

* UNTIL 830 PM CDT

* AT 748 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR
LIVINGSTON...OR 12 MILES WEST OF HAMMOND...MOVING WEST AT 35 MPH.

* THE TORNADO WILL BE NEAR...
WALKER BY 805 PM CDT...
6 MILES SOUTH OF DENHAM SPRINGS BY 815 PM CDT...
PRAIRIEVILLE BY 825 PM CDT...
OAK HILLS PLACE...WESTMINSTER...GARDERE AND 8 MILES SOUTHEAST OF
BATON ROUGE BY 830 PM CDT...

[GoneBabyGone]

Tornado warning in EBR

[Wthrman13]

Shear doesn't work that way... it's a difference between winds at different levels. 20 kts of shear is still 20 kts of shear, whether the difference is between an 80 kt wind aloft and a 60 kt wind below, or the difference between a 30 kt wind aloft, and a 10 kt wind below, and so on.

A hurricane moves with the steering flow, which is some weighted average of winds over a depth of the atmosphere, and is different for every system. A hurricane that is stationary and getting sheared from the south, if it started to move north, would experience less shear, not because it was moving "with" the shear, but because the low-level environmental winds have begun to line up more with the upper-level winds, both starting to move the hurricane north, and decreasing the shear at the same time.

I hope that makes sense, and any other met on here who wants to chime in with corrections or additions, please do so..

OK - so it IS more like what we see with supercells (which, as you can tell from my location is a lot higher focus as it is for you I'm sure).

Thanks for the clarification!

Yes, since my focus is mainly on supercells, I have that mindset when I think of shear, and have found it useful applying it to TC's as well.

[BigB0882]

Baton Rouge under tornado warning now, as well.

[Sabanic]

Strong band that went through N.O is strengthening and now extends from LA and through MS, probably a feeder band now I'd guess.

Also main rainshield is just a little bit to the SE of Mobile, should move inland over MS and LA in the next 2hrs, should see a rapid increase in TS force wind speeds soon.

After it comes through here

[CYCLONE MIKE]

Another tornado warning just issued for Baton Rouge, Livingston, and Ascension parishes!!! Sorry did not see the other posts.

[Category 5]

I'm afraid I have to call out the SPC here on the gross lack of a tornado watch.

[RainWind]

A tornado warning has just been issued to go right over my house. Oh my, this is not good. RW