ATL: DEBBY - Post-Tropical

[Air Force Met]

I'm going to have to disagree with you there. Just looking at satellite imagery can show you that there is a building anticyclone located in the southwest Gulf of Mexico. Shear tendency maps show that wind shear has been lowering over the Gulf of Mexico for the past 24 hours, and it should continue to do so as the anticyclone expands. Any upper-level low near the system is likely far enough away to /not/ shear it and will likely help evacuate air instead.

First. If there is a AC in the SW GOM, that will impart shear. To a little AC I say big whoop. Second. Make it a MONSTER AC and it doesnt change what is happening at the surface: a disorganized, broad low spitting out votices. Which goes back to my main point: this is not a TD.

And all of this doesn't change what is happening right over the center of the gyre: a battle of west and east winds. That's a fact and isn't open for debate.

[Air Force Met]

The fact its shooting that out is indications its not quite organized or the environment is ot conclusive enough yet... more waiting is required.

As we spoke about earlier (I'll use my analogy), these gulf systems are like cranking an old lawnmower. You have to pull the handle a few diurnal cycles to get a good LLC. Then of course it will get sheared and reform to the NE. Lol

[StormClouds63]

NATIONAL WEATHER SERVICE LAKE CHARLES LA
413 PM CDT FRI JUN 22 2012

THE REAL CHALLENGE AT THIS POINT DURING THE FORECAST IS WHAT TO DO
ABOUT THE LOW PRESSURE SYSTEM NEAR THE YUCATAN PENINSULA. NHC IS
STILL GOING WITH A 70 PERCENT CHANCE SO IT IS LIKELY TO FORM PER
THEIR FORECAST. THEREFORE APPROACHED THE FORECAST ASSUMING IT WILL
FORM AND COLLABORATED WITH SURROUNDING OFFICES CONCERNING WINDS AND
WAVES. MOST OF THE GUIDANCE MODELS ALL AGREE ON NORTHWARD MOVEMENT
TOWARDS THE BIG BEND REGION OF FLORIDA THROUGH SUNDAY AROUND 00Z.
THEN THE GFS TAKES THE SYSTEM EASTWARD ACROSS FLORIDA AND INTO THE
ATLANTIC. ALL OF THE OTHER GLOBAL MODELS DRIFT THE SYSTEM BACK TO
THE WEST AND GIVEN THAT... WENT WITH A COMPROMISE OF THAT SOLUTION.
ONE VERY INTERESTING VERSION IS THE CANADIAN MODEL WHICH DEVELOPS AN
INTENSE TROPICAL CYCLONE AND AS OF THE LATEST MODEL RUN IT HAS THE
STORM MAKING LANDFALL IN THE TEXAS COAST ALBEIT IS WAY TO EARLY TO
MAKE JUDGMENTS BASED ON JUST ONE MODEL GIVEN THAT NHC HAS YET TO
NAME THE SYSTEM. WINDS AND WAVE HEIGHTS WILL PICK UP ESPECIALLY OVER
THE COASTAL WATERS BEGINNING MONDAY AS THIS STORM BEGINS TO MOVE
TOWARDS THE WEST. RIGHT NOW HAVE SMALL CRAFT EXERCISE CAUTION
THROUGH TOMORROW AT 00Z BUT THAT WILL HAVE TO BE EXAMINED FOR A
POTENTIAL SMALL CRAFT ADVISORY AS WINDS AND WAVES BEGIN TO INCREASE.
WILL CONTINUE TO MONITOR AND COLLABORATE WITH SURROUNDING WFOS AND
NHC REGARDING THIS SYSTEM AND FURTHER DEVELOPMENT.NEED TO STRESS
THAT THIS SYSTEM HAS NOT YET BEEN NAMED NOR HAVE ANY ADVISORIES BEEN
ISSUED THEREFORE MUCH OF THE GULF COAST SHOULD MONITOR PRODUCTS AND
INFORMATION COMING FROM NHC REGARDING ANY AND ALL FUTURE DEVELOPMENT
WITH THIS SYSTEM.

[Sanibel]

Appears to be a spiral center near 23N-86.5W (Close to GFS spot)

Like I said on page 14.


Edit: Appears to be shooting out too quickly to be surface center vortex.

[Portastorm]

Please highlight the relevant area of the forecast discussion and include some comments from you on why it is relevant ... or, better yet, just include the relevant snippet.

We will have an increasing amount of traffic on here as this system possibly ramps up this weekend and threatens someone on the Gulf Coast. That means more posts and less time to read them, so that is why we (the moderators) are asking for folks to put their clips from other sources into context. Thank you!

[tailgater]

They have it pinpointed about where most of us think it will consolidate.

[Evil Jeremy]

18z GFS has been rolling, and it's showing 96L heading towards the big bend again:

[Evil Jeremy]

AT THIS TIME...NHC IS LEADING ON THE 00Z ECMWF AND 00Z CANADIAN MODELS ON MOVING THE LOW WESTWARD TOWARDS TEXAS EARLY NEXT WEEK.

So the Center is favoring ECMWF/CMC at this time over GFS/GFDL/HWRF... Lets see if that changes with the upcoming model suite. Nice to hear what they are thinking right now, even if it's secondhand from the Miami NWS office.

[Aric Dunn]

The fact its shooting that out is indications its not quite organized or the environment is ot conclusive enough yet... more waiting is required.

As we spoke about earlier (I'll use my analogy), these gulf systems are like cranking an old lawnmower. You have to pull the handle a few diurnal cycles to get a good LLC. Then of course it will get sheared and reform to the NE. Lol

exactly. its actually amazing the complexity of variables that need to be considered. its always a process and because the nature of a "tropical" system... you have to have a certain level of persistent heating ( through latent heat release ) to produce a tropical system ... you add in variables of shear and well atmospheric physics you can only start to understand the process of how they organize. pressure, temperature, density, depth, ( the rest is included in many physical constraints.)

[PTrackerLA]

Yep 18z GFS holding it's ground. Such extreme model differences and an undefined low level center. Try again tomorrow folks!

[Weatherfreak000]

I'm confused about 96L. Sure it will be Debby I think...but it looks much less organized today than I imagined.

[tolakram]

I'm confused about 96L. Sure it will be Debby I think...but it looks much less organized today than I imagined.

All the reliable global models delayed development until tomorrow or Sunday. I think it's proceeding as expected, but certainly slow.

[ROCK]

18Z still wants to go across FL...either it's going to major bust or be a big winner after this...

[cycloneye]

Is a very large entity.



Uploaded with imageshack.us

[Dean4Storms]

Once again the GFS never has the low get to 90W, which I have a hard time seeing with what is transpiring!

[Weatherfreak000]

That's why I don't understand comments like the models will do this or that....this one is tough to forecast.

[southerngale]

It may be slow to develop, as expected, but it looks like it's getting much larger overall.

[tolakram]

If you look at the latest loop you can start to see inflow setting up on the west side.



Live loop: http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... umframes=5

[tolakram]

I'm thinking if the GFS is going to flip it will be on the full run, not the 6z or 18z. Remind me again what the full run has that the intermediate does not?

[bella_may]

all the models are still initializing this too far west IMO