ATL HANNA: Extratropical - Discussion

[cpdaman]

thought little swirl was going NW , but last frame shows west "wobble" so still wnw right at the ull, hanna go right for it...........please go quietly

[KWT]

cpdaman, well this is going to remain under shear for a long time, I sure hope this doesn't end up like Td10 in 2005....

[tgenius]

I think its going to be a long labor day weekend...

[HURRICANELONNY]

As per the NHC discussion. The strength depends on the track of the ULL.If the ULL heads SW then further strengthening. If not then back to a depression or no immediate Hurricane.

[gatorcane]

given the more WNW movement today instead of NW and the trend of the GFS and Euro to bend more SW in the 5+ day range, I expect to see a slight left shift in the overall cone with a bit more of a noticeable bend to the WSW.

[Vortex]

Exerpt From NWS Melbourme afternoon package:


NEXT WEEK...IT APPEARS THAT THE ECM RUNS OF THE PAST FEW NIGHTS YET
AGAIN HAD THE RIGHT GENERAL IDEA W/R/T THE SYNOPTIC PATTERN OVER THE
ERN CONUS-WRN ATLC AS THE MORE RELIABLE GLOBAL MODEL GUIDANCE HAS
TRENDED TWD ITS SOLNS...BOTH SFC AND ALOFT. HOWEVER...THERE STILL
REMAINS SOME PRETTY SIGNIFICANT DIFFERENCES W/R/T THE EVOLUTION OF
THE STRONG ERN CONUS DLM RIDGE AND A DEEP LYR CUTOFF LOW INITIALLY
OVER OVER THE CNDN MRTMS WHICH DROPS SOUTH OR SSE OVER THE WRN ATLC.
DEPENDING ON WHICH MODEL YOU TRUST MORE...THIS LARGE RIDGE WILL
EITHER 1) PUSH EASTWARD INTO THE WRN ATLC...SHOVING THE LOW ESE-WD
MORE TWD THE CTRL ATLC (GFS); OR 2) REMAIN OVER THE ERN CONUS AS THE
DEEP LYR LOW DROPS SOUTH TO SSW OVER THE WRN ATLC (ECM).

EVEN WITH THESE EVOLVING DIFFS...WHAT DOES APPEAR LKLY FOR MUCH OF
NEXT WEEK IS THAT A FAIRLY EXPANSIVE SFC HIGH PRES RIDGE WILL HOLD
SWAY OVER THE ERN CONUS...WHICH WILL KEEP ECFL IN A PD OF MDT TO
PSBLY BRISK LOW LEVEL EASTERLIES...WHICH HAS BEEN IN ABSENTIA FOR
ALMOST THE ENTIRE SUMMER. FCST WILL CONTINUE REGIME OF LATE NIGHT
AND EARLY MORNING SHRA WITH LOW END SCT POPS CONTINUING THROUGH THE
AFTN. SHOULD EASTERLIES BE AS BRISK AS FCST...SHRA WILL BE MORE
PREVALENT THAN TS.

THE BIG UNCERTAINTY IN THE FCST...ESPECIALLY FOR DAYS 6-7...IS HOW
THE AFOREMENTIONED DEEP LAYER FEATURES AFFECT THE EVENTUAL TRACK OF
TS HANNA. INITIAL FCST TRACK TAKES IT NW...THEN TURNS IT WNW TO WEST
IN THE GENERAL DIRECTION OF THE N. BAHAMAS BY EARLY NEXT WEEK AS IT
STRENGTHENS INTO A HURRICANE. WE WILL BE WATCHING THIS CLOSELY.
REFER TO NATIONAL HURRICANE CENTER PRODUCTS REGARDING TROPICAL
DEPRESSION EIGHT.

[alienstorm]

Looking at Water Vapor loop the ULL seems to be stationary or a slight move to the east. Given this Hanna LLC would traverse the ULL and if it can survived (which would be highly unlikely) then it would head off to the west or even WSW in time.

Right now I would say there is a better than even chance that Hanna will be downgraded to a Depression later today, this reminds me of Andrew in the sense that Andrew ran into a ULL east of the islands and basically became a naked swirl, once it traverse the ULL and once it ran into the blocking high at 30N it turn west and the rest is history. I am not saying the same thing is going to happen with Hanna but she does have a rather vigiorous LLC....

[Vortex]

With much respect I remember Andrew like it was yesterday..To see hanna going through a sheared state and nearly the identical place as Andrew with a very similar forecasted type ridge to build over the east coast/western atlantic is downright CHILLING.

[gatorcane]

I'm leaning towards it surviving the ULL -- there is just way too much vorticity and convection (albeit sheared) for it to go poof I'm afraid.

Latest:

[KWT]

Its hard to say gatorcane, this ULL seems to still be drifting a touch further east and the both are getting closer to each other, even if the ULL dives SW now looks like this is going to have to survive some pretty strong shear for a while yet.

It will survive in some form even if the system does open up, as you say there is a lot of energy with this system and to think its going to die and go away is pretty foolish.

[Brent]

With much respect I remember Andrew like it was yesterday..To see hanna going through a sheared state and nearly the identical place as Andrew with a very similar forecasted type ridge to build over the east coast/western atlantic is downright CHILLING.

I've been thinking about Andrew today to for that reason.

[txwatcher91]

Just a thought, what would happen if the LLC moved UNDER the ULL? Would they merge or what?

[gatorcane]

Just a thought, what would happen if the LLC moved UNDER the ULL? Would they merge or what?

I don't think that is what will happen but good question and I don't know.

But if you look carefully I am starting to see that pesky ULL ever-so-slowly starting to drift WSW --- just like the models were saying it would...

http://metofis.rsmas.miami.edu/~dortt/s ... 1_loop.gif

Another thing I want to mention is look at the super impressive outflow pattern we are seeing with Hanna, especially on the SE and E quads....very impressive.

[DESTRUCTION5]

Just a thought, what would happen if the LLC moved UNDER the ULL? Would they merge or what?

Humm LLC with a ULL...Maybe it would pruce a MLL...LOL

[KWT]

Yep I see that as well gatorcane, ULL is now starting to pull WSW, the exposed LLC of Hanna now heading WNW, still shear should be with it for a while yet.

[cpdaman]

was the initial NW motion based on this being a bit stronger and in the 500-850 nw flow

seems it is weaker and in the low level flow heading right for the spin of death

by the way does anyone remember if andrew's LLC went literally thru the ULL's center - i have a hard time believing it did and survived-

[gatorcane]

was the initial NW motion based on this being a bit stronger and in the 500-850 nw flow

seems it is weaker and in the low level flow heading right for the spin of death

by the way does anyone remember if andrew's LLC went literally thru the ULL's center - i have a hard time believing it did and survived-

it doesn't matter, see my post above, the ULL is starting to gradually pull WSW like the models forecasted.

[Bocadude85]

You know there was a hurricane back in 1947 that moved northwest only to go wsw and enter the coast of Florida around south palm beach or northern broward counties as a category 4 hurricane

[cpdaman]

was the initial NW motion based on this being a bit stronger and in the 500-850 nw flow

seems it is weaker and in the low level flow heading right for the spin of death

by the way does anyone remember if andrew's LLC went literally thru the ULL's center - i have a hard time believing it did and survived-

it doesn't matter, see my post above, the ULL is starting to gradually pull WSW like the models forecasted.

gator with all respect i can't see this ull moving WSW now

http://metofis.rsmas.miami.edu/~dortt/s ... 1_loop.gif better detail there

all i see is that the convection on the east side of the ULL appears to be moving closer to the ull's center, i thought i saw the ULL moving wsw earlier this morning, i'm not so sure it's moving yet...but hey i could be wrong

[gatorcane]

look at this WV loop at the bottom of it....you can see the ULL has started to drift WSW now (unfortunately)

http://metofis.rsmas.miami.edu/~dortt/s ... 1_loop.gif