Tropical Storm Isaac, Part 2: Isaac Moving Into The Gulf Of Mexico-Hurricane Warnings For Morgan City, LA/MS/AL & FL Panhandle To Destin, FL

[DopplerWx]

Where does isaac go post landfall? does the trough pick it up?

[wxsmwhrms]

Where does isaac go post landfall? does the trough pick it up?

No, that seems to be an idea that was in the 12Z run that the GFS has given up on, at least for now. After landfall it just drifts due N through AL/TN and eventually into W KY. The 18Z run actually had it keep going WNW more like the ECMWF did.

[wxsmwhrms]

Hard to tell with not greatest of graphics, but looks like the UK is a bit left of the GFS through 72 hours, probably just S of EYW at that point. 500 mb heights are definitely higher N of the storm in the 48-72 hour period on the UK than the GFS.

[jhamps10]

No, that seems to be an idea that was in the 12Z run that the GFS has given up on, at least for now. After landfall it just drifts due N through AL/TN and eventually into W KY. The 18Z run actually had it keep going WNW more like the ECMWF did.

Which would be the best track, brings the lower Ohio and Mississippi valley some MUCH needed tropical rains to ease our drought..

[OSUmetstud]

while the final tracks aren't all that different...the EC makes landfall 50 to 60 hours later than gfs. Big difference with respect to the strength of the ridge.

[wxsmwhrms]

Which would be the best track, brings the lower Ohio and Mississippi valley some MUCH needed tropical rains to ease our drought..

No argument there. Anything that could get some rain up into the Ohio and Mid-MS valleys and get some water into the MS River would be a positive to me.

That is an expansive area of -80C cloud tops SW of the center.

[Normandy]

Call me crazy, but this storm in no way, shape, or form looks like its going to pass over Hispanola. It also seem slike the southern vortex is winning the battle for now. When is the next recon?

[LakeEffectKing]

Haven't posted much tonight.....computer problems/virus....} see we still have acontroversy over the location of the coc.

[Superstorm93]

Call me crazy, but this storm in no way, shape, or form looks like its going to pass over Hispanola. It also seem slike the southern vortex is winning the battle for now. When is the next recon?

USAF plane just took off from St. Croix

Should begin fixes at 1:30 am

[uofmiami]

Haven't posted much tonight.....computer problems/virus....} see we still have acontroversy over the location of the coc.

Yes, Issac is a hot mess still. Might have to wait til he gets into the GOM before he gets his act together it appears.

[wxsmwhrms]

Hard to tell with not greatest of graphics, but looks like the UK is a bit left of the GFS through 72 hours, probably just S of EYW at that point. 500 mb heights are definitely higher N of the storm in the 48-72 hour period on the UK than the GFS.

UK is left of the GFS earlier in the period,but then goes quite a bit right of the GFS and its previous run in the end. Takes it into PAM-AQQ in about 120 hours then N into NW GA.

[Superstorm93]

I know it's going to fall apart and cause me to take a 48 hiatus from the system, but it has gotten more symmetrical over the past hour and a half.

Oh well.

[wxsmwhrms]

hmmmm...looks like the GFS clearly sees a weaker ridge...Lets see if the euro follows it

After seeing the UK, I have to think it does shift east. I am not sure that it was the G-IV data or something else given that the UK's main change comes after 72 hours, but it seems like the 00Z runs have nudged back a bit to the east, and the UK shifting as far east as it has makes me think the EC has to be well too far west.

[HurricaneJosh]

Hey! I've been with clients for the last 8 hr-- I'm totally out of the loop! What's the latest with regard to the center, the heading, and the models?

[Superstorm93]

Hey! I've been with clients for the last 8 hr-- I'm totally out of the loop! What's the latest with regard to the center, the heading, and the models?

Center: Totally questionable. NHC has it at 16.7N, but look at IR. I'm not feeling that right now. Recon is en-route.

Heading: Depends on the real center location. NHC has it WNW @ 18mph. Convective mass is heading west (FWIW)

[wxsmwhrms]

UK is left of the GFS earlier in the period,but then goes quite a bit right of the GFS and its previous run in the end. Takes it into PAM-AQQ in about 120 hours then N into NW GA.

The UK and the Canadian both end up in the same place around PAM-AQQ, although the Canadian gets there about 24 hours sooner and comes in more from the ESE while the UK comes in more from the due south with a longer period over the Gulf (48-60 hours over water from emergence off Cuba to landfall near PAM). Not sure what to think about the UK being over with the Canadian, LOL.

[Camille>Katrina]

Actually yeah, I shouldn't have mentioned Katrina, to tone down the hype machine.That's my bad there. I suppose that the storm surge is proportional to some integrated quantity that involves the wind speed distribution in the cyclone. But obviously, the potential is there, and I felt like it ought to be brought up at some point now that the N GOM solution is becoming more likely.

Well as it was explained to me it was called fetch!!Fetch was the extent of the the 75+ winds over a period of time/distance to build up water and collase it to shore in great masses The 75mph winds of Katrina were reported all the way to Mobile thus the flooding worse than Fredrick,Hurding in cows one might say

Got alot of guys who know there stuff and all I want to is read #1 and and maybe ask that question.

[HurricaneJosh]

Center: Totally questionable. NHC has it at 16.7N, but look at IR. I'm not feeling that right now. Recon is en-route.

Heading: Depends on the real center location. Convective mass is heading west (FWIW)

Thanks, Super.

[SN_Lover]

I know it's going to fall apart and cause me to take a 48 hiatus from the system, but it has gotten more symmetrical over the past hour and a half.

Oh well.

It does actually looks ALOT more organized now. Nice convection firing up and everything. Looks like dry air to the storms NW has abated too from the water vapor imagery.

[wxsmwhrms]

Before I hit the sack I wanted to point something out I have been looking at this evening. I was surprised to see the UK come as far right as it did given that the 500 mb heights look higher this run at the 96-120 hour period than the previous. However, I want to point out something that's going on even higher up. The global models (at least the GFS/EC so I assume they all are) are breaking off an upper level low over the central or western Gulf out around 4-5 days out of the upper trough currently over the area. The GFS looks to have it offshore south of New Orleans at 96 hours. Check it out here if you want:

http://mag.ncep.noaa.gov/NCOMAGWEB/appcontroller?prevPage=Model&MainPage=indexℑ=&page=Param&cycle=08%2F24%2F2012+00UTC&rname=UPPER+AIR+PARMS&pname=250_wnd_ht&pdesc=&model=GFS&area=NAMER&cat=MODEL+GUIDANCE&fcast=096&areaDesc=North+America+-+US+Canada+and+northern+Mexico&prevArea=NAMER&currKey=model&returnToModel=&imageSize=M

The 18Z run was a bit farther west with this feature, so my guess is that this is playing a key role in how quickly the system gets turned more northerly and where the ultimate landfall point is. We don't look very often at this level, but clearly if the system gets as strong as implied by the models, upper level steering will play a role that 500 mb won't show us. I am suspecting that the UKMET is farther east with this feature on its 00Z run, resulting in the landfall farther east toward PAM/AQQ. The 12Z EC, conversely, broke this upper low off well SW of the other models, which probably plays a big role in why it goes so far west with Isaac. My experience is the models are notoriously poor with forecasting these types of features, and if this is going to play a key role in Isaac's ultimate track, it will probably result in model waffling for a while yet.

[Superstorm93]

Convection is already beginning to wane throughout the mass. Probably going to wait for a center fix, then I'm out.

Pending on how this progresses tonight, I may need a break from this one.

[wxsmwhrms]

Looks like the 00Z GEFS cluster still support the op run with a track to near MOB/PNS then up into western AL. In fact, at 120 hours the op GFS and GEFS mean are right on top of each other. But interestingly the spread between the extremes increased this run, with one member all the way SW going into like VCT, and a couple getting picked up by a trough after landfall and going ENE to off the Carolinas eventually.

[dan88]

At the very least, it looks like the center is a good deal South of the 16.9N the advisory puts it at. Recon is flying due South along 69.6W, and it's down to 16.4N with East winds and still decent surface winds on the SFMR, and extrap pressure still falling (down to 1001.2mb)

[Minnesota Meso]

First of all thank you to all the pro mets, your discussion is a real cool read, I was trying to catch up on your post, but we had a nadar warned storm in MN a few hours ago that kind of got my attention. I'm learning a lot by reading it. The question I have is this, have any of your watched the video that was posted on the banter thread? and if so your thoughts?

[Dsnowx53]

Before I hit the sack I wanted to point something out I have been looking at this evening. I was surprised to see the UK come as far right as it did given that the 500 mb heights look higher this run at the 96-120 hour period than the previous. However, I want to point out something that's going on even higher up. The global models (at least the GFS/EC so I assume they all are) are breaking off an upper level low over the central or western Gulf out around 4-5 days out of the upper trough currently over the area. The GFS looks to have it offshore south of New Orleans at 96 hours. Check it out here if you want:

http://mag.ncep.noaa.gov/NCOMAGWEB/appcontroller?prevPage=Model&MainPage=indexℑ=&page=Param&cycle=08%2F24%2F2012+00UTC&rname=UPPER+AIR+PARMS&pname=250_wnd_ht&pdesc=&model=GFS&area=NAMER&cat=MODEL+GUIDANCE&fcast=096&areaDesc=North+America+-+US+Canada+and+northern+Mexico&prevArea=NAMER&currKey=model&returnToModel=&imageSize=M

The 18Z run was a bit farther west with this feature, so my guess is that this is playing a key role in how quickly the system gets turned more northerly and where the ultimate landfall point is. We don't look very often at this level, but clearly if the system gets as strong as implied by the models, upper level steering will play a role that 500 mb won't show us. I am suspecting that the UKMET is farther east with this feature on its 00Z run, resulting in the landfall farther east toward PAM/AQQ. The 12Z EC, conversely, broke this upper low off well SW of the other models, which probably plays a big role in why it goes so far west with Isaac. My experience is the models are notoriously poor with forecasting these types of features, and if this is going to play a key role in Isaac's ultimate track, it will probably result in model waffling for a while yet.

Heh, this could actually be a Euro bias of hanging back mid and upper level energy to the SW...doesn't mean it's wrong, of course, but that is a bias it has.

[Superstorm93]

ECMWF initializes the low just tad N of 15N and shoots it NNW into Hispaniola. That would be the only way it hits the island.

Looks remarkably similar to the 00z GFS through 72 hours.

Hurricane in the Florida Straights.

[deltadog03]

HR72....its Moving WNW-NW and just south of Key West....strengthening still....

[Dunkman]

Question for anyone who knows more than me (which is most of you)...on the first 24h frame of the Euro what is that 1005mb low pressure west of Isaac? Did one of the centers break off and race ahead of the storm? (I could post the frame but I'm sure everyone still awake has seen it)

[Superstorm93]

Question for anyone who knows more than me (which is most of you)...on the first 24h frame of the Euro what is that 1005mb low pressure west of Isaac? Did one of the centers break off and race ahead of the storm? (I could post the frame but I'm sure everyone still awake has seen it)

That would be your Lee cyclone that spins off from the mountains of Hispaniola.

This has been shown for the past five days now. Seems decently likely to happens.

[Superstorm93]

Recon isn't finding a center anywhere near where the NHC has it.

EURO bombing Isaac out after moving through the Florida keys. Still heading WNW