ATL HANNA: Extratropical - Discussion

[Bocadude85]

Hanna growing by the hour:

She looks to be the size of the state of Florida

[KWT]

Certainly is a big convective burst, I'm guessing the shear is helping to blow the convection up on the eastern side of the system?

[Blown Away]

at this point I think the 00Z UKMET has a good handle on current and forecasted movement.

I agree, it moves Hanna generally WNW then gradually bends it back WSW in response to the ridge. The flow makes sense and does not have all those herky jerky 90 degree turns, etc. Sends Gustav WSW in the Gulf???

[DESTRUCTION5]

at this point I think the 00Z UKMET has a good handle on current and forecasted movement.

I agree, it moves Hanna generally WNW then gradually bends it back WSW in response to the ridge. The flow makes sense and does not have all those herky jerky 90 degree turns, etc. Sends Gustav WSW in the Gulf???

Im thinking were not gonna see this monster dip but more of a subtle Katrina one when the High lays on her...then a due west motion...

[bob rulz]

I don't even want to imagine the possibility of Gustav hitting the Gulf Coast, followed by Hanna either moving over South Florida and moving into the Gulf or missing Florida to the south (that would be one hell of a ridge) and moving into the Gulf as well. I don't usually give into hyberbole but these twin storms are looking pretty scary at the moment.

[jlauderdal]

Hanna growing by the hour:

She looks to be the size of the state of Florida

i would like to stick that sat picture right up the you know what of the people that wrote off the season a few weeks ago..this is a highly unusual situation having two impressive looking systems and intensifying so close together both threatening the united states within days of each other.

[DESTRUCTION5]

http://www.ssd.noaa.gov/goes/flt/t2/vis-l.jpg

Looks like she ingested her LLC again...She's dressed this morning..

[KWT]

Yeah the GFDL is way too extreme I feel, would love to see any system that has done that in the summer!

However a SW motion isn't at all impossible and who knows, quite a few of the models are very keen on taking this as far south as the Keys eventually.

Who knows but a 1-2 hit for the central gulf would be madness!

[cpdaman]

http://www.nhc.noaa.gov/text/refresh/MI ... 1453.shtml

A 1031 UTC QUIKSCAT OVERPASS WAS VERY HELPFUL IN LOCATING THE CENTER
OF HANNA EARLY THIS MORNING. VISIBLE IMAGERY SHOWED THAT THE CENTER
BRIEFLY BECAME EXPOSED...HOWEVER...NEW CONVECTION FORMED SINCE THAT
TIME AND THE CENTER IS POSITIONED JUST BENEATH THE COLDER CLOUD
TOPS. DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB CONTINUE TO
SUPPORT 45 KT...SO THE INITIAL INTENSITY REMAINS UNCHANGED. IN THE
NEAR TERM...THE DYNAMICAL MODELS SUGGEST THAT THE UPPER-LOW TO THE
WEST-NORTHWEST OF HANNA WILL MOVE WESTWARD AND WEAKEN...WHICH
SHOULD RELAX THE SOUTHWESTERLY SHEAR THAT IS CURRENTLY IMPINGING
UPON THE CYCLONE. THE INTENSITY FORECAST FOLLOWS THIS SOLUTION
AND CALLS FOR GRADUAL STRENGTHENING DURING THE NEXT 2 DAYS...
BRINING HANNA TO HURRICANE STATUS. THEREAFTER THERE IS A LARGE
AMOUNT OF UNCERTAINTY IN THE INTENSITY FORECAST. THE GLOBAL MODELS
PREDICT STRONG NORTHWEST TO NORTH UPPER-LEVEL WINDS OVER
HANNA...WHICH ONE WOULD THINK SHOULD HALT ADDITIONAL STRENGTHENING
OR EVEN WEAKEN THE STORM. HOWEVER...NEARLY ALL OF THE INTENSITY
GUIDANCE SHOW STRENGTHENING OR LITTLE INTENSITY CHANGE DURING THAT
TIME. ASSUMING THAT THE SHEAR WILL PRODUCE A NEGATIVE AFFECT ON
HANNA...THE NEW INTENSITY FORECAST FOLLOWS PERSISTENCE OF PREVIOUS
ADVISORY AND IS A LITTLE BELOW MOST OF THE GUIDANCE.

HANNA MOVED WEST-NORTHWESTWARD DURING THE PAST 12 HOURS AND THE
INITIAL MOTION ESTIMATE IS 285/10. THE TRACK GUIDANCE IS
IN GOOD AGREEMENT THROUGH 48 HOURS ON A WEST-NORTHWEST TO NORTHWEST
MOTION. THEREAFTER...THE MODELS GENERALLY SHOW A WEST-
SOUTHWESTWARD OR SOUTHWARD TURN..SOUTH OF A BUILDING RIDGE OVER
THE EASTERN UNITED STATES. HOWEVER...THE SHARPNESS OF THE TURN
AND SPEED OF MOTION VARIES GREATLY. THE NEW NHC TRACK HAS BEEN
ADJUSTED SOUTHWARD DURING THE FIRST COUPLE OF DAYS...MAINLY DUE TO
THE MORE WESTWARD INITIAL MOTION. THIS IS IN CLOSE AGREEMENT WITH
THE MODEL CONSENSUS. AFTER 72 HOURS...THE NEW TRACK IS A LITTLE
FASTER THAN THE PREVIOUS ADVISORY...BUT IS NOTICEABLY SLOWER THAN
THE UKMET AND GFDL MODELS. THE HWRF...WHICH SHOWS A CYCLONIC LOOP
NORTH OF THE BAHAMAS AND A NORTHEASTWARD MOTION AT DAY 5...IS
CONSIDER AN OUTLIER AT THIS TIME.

[HURAKAN]

Look at that!

[gatorcane]

I think in the discussion they meant SOUTHEASTERN Bahamas not SOUTHWESTERN:

INTERESTS IN THE SOUTHWESTERN BAHAMAS AND TURKS AND CAICOS SHOULD
MONITOR THE PROGRESS OF HANNA. IMPACTS IN THESE AREAS COULD OCCUR
MUCH SOONER THAN INDICATED BY THE EXACT TRACK...ESPECIALLY IF THE
MORE NORTHWESTWARD MOTION DOES NOT MATERIALIZED LATER TODAY OR ON
SATURDAY.

[Blown Away]

Funny how I think it was the EURO showing a giant hurricane near SFL a while back. Hanna looks like she will be a giant system.

[KWT]

Crazy forecast from the NHC!!!, look how far it digs SW. The forecasts of weakening from the shear looks pretty reasonable right now but we shall see.

The question is does it turn back west or does it bury itself into Cuba?

[Derek Ortt]

Crazy forecast from the NHC!!!, look how far it digs SW. The forecasts of weakening from the shear looks pretty reasonable right now but we shall see.

The question is does it turn back west or does it bury itself into Cuba?

Even Haiti may be in play according to GFDL

That would be the ultimate doomsday scenario. The last thing Haiti needs is another hurricane

[KWT]

Could that relaly happen though Derek, head near due south for such an extended time?

the ultimate question has to be will it make it into the gulf?

[Bocadude85]

That would be one crazy track if she dove into cuba and haiti.. I wonder what happens if the more northwest track the NHC talks about doesnt happen? Seems they say she could get into the bahamas much sooner then forcast if she doesnt go more NW.. how would that change the track?

[gatorcane]

Certainly could but I'm not buying a High that is that strong. That would be one heck of a High building in not to mention the Euro has shown the bend back to the west and then WNW through Southern FL or just south of Southern FL for nearly 2 days straight now. The GFS had Hanna going through St. Lucie county last night (now shifted back south). Of course the GFDL is way south....

Not sure what to believe at this point.

[cpdaman]

Certainly could but I'm not buying a High that is that strong. That would be one heck of a High building in not to mention the Euro has shown the bend back to the west and then WNW through Southern FL or just south of Southern FL for nearly 2 days straight now. The GFS had Hanna going through St. Lucie county last night (now shifted back south). Of course the GFDL is way south....

Not sure what to believe at this point.

it had better not Gator, we could be dealing with a very strong storm ( a major) depending on the flow /shear from the high

[tolakram]

http://markalot.org/gearth.html

[bahamaswx]

I think in the discussion they meant SOUTHEASTERN Bahamas not SOUTHWESTERN:

INTERESTS IN THE SOUTHWESTERN BAHAMAS AND TURKS AND CAICOS SHOULD
MONITOR THE PROGRESS OF HANNA. IMPACTS IN THESE AREAS COULD OCCUR
MUCH SOONER THAN INDICATED BY THE EXACT TRACK...ESPECIALLY IF THE
MORE NORTHWESTWARD MOTION DOES NOT MATERIALIZED LATER TODAY OR ON
SATURDAY.

We all got the point here.