ATL HANNA: Extratropical - Discussion

[Ground_Zero_92]

I know I should know better then booking a cruise for the peak of hurricane season, but it was the only time we could both get the time off. We leave Port Everglades on Thursday, Sept 11. Goes to Key West then Cozumal Mexico. Returns on Sept 15. How likely is it that weather may impact this? Should Hanna have passed us by then? I am concerned because of the stall the models show and the general threat from central Florida to the south.

Here in SFL, I am on the edge of my seat. There is alot of uncertainty on where this will end up, and if it does come our way, it could be huge.

No need to be on the edge of your seat -- Florida is about 7-8 days out from a hit and alot can change especially 5+ days out.

[KWT]

Who knows Delta, the shear maybe pretty severe for a while if it does get into Gustav's outflow but that may not last all that long once Gustav is inland.

Indeed the NHC states that the set-up may be very favorable between 72-96hrs for strengthening.

[punkyg]

Question where is the center located?

I can't tell.

[HURRICANELONNY]

If JB says it will hit Florida. I know I'm in the clear.

[wxman57]

Question where is the center located?

I can't tell.

Definitely not west of the convection, and probably not under the convection. I.E., it doesn't appear to have one. But I think it'll redevelop under the convection over the next 24 hours.

[cpdaman]

appears to be something

near 21.5 62.3/.4 would this be pretty much wnw from when it was last seen prior to visible=

partially exposed with a lil convection trying to build on east side of LLC

http://www.ssd.noaa.gov/goes/flt/t2/loop-vis.html

yes it's the LLC! you can't tell me that vigoruous spin we saw last evening dissapeared last nite in moderate south shear

[KWT]

That would be a big shift back to the SE and given the set-up we have...would relaly bring the Caribbean into play given the WSW/SW motion the models are progging.

[cycloneye]

The 12:00 UTC Best track:

AL, 08, 2008082912, , BEST, 0, 210N, 624W, 45, 1000, TS,

[Thunder44]

looks poor IMO

where is the low , thunder i don't see it

http://www.ssd.noaa.gov/goes/flt/t2/loop-ir2.html

is that it by 21.3 61.6 or so

http://www.ssd.noaa.gov/goes/flt/t2/loop-avn.html

convection was most impressive last nite se of center (even all the way down south and east of the leeward island (17-19) but that SSE most area of convection is weakening

and the main blob just se of center (around 20/59.5) is still steady

upper level divergence is now excellent but not over the center (to the SSE)

http://cimss.ssec.wisc.edu/tropic/real- ... g8dvg.html

Earlier this morning, I saw a swirl on the 8:15 UTC IR2 image, not far from where the NHC positioned it at 5am EDT. It looks like it moved NW and diminished. It wasn't a true center. I agree with Wxman57. From looking at visible imagery now this storm doesn't appear to have a closed LLC now.

[ericinmia]

That would be a big shift back to the SE and given the set-up we have...would relaly bring the Caribbean into play given the WSW/SW motion the models are progging.

Not necissarily...

If the ridge is forecast to be in position A and the storm is farther north it will push it to position C. But if the storm is farther south than its projected north position the ridge will still only be able to push it to Position C. The difference should be very minor, based upon the center of the ridge axis... the force should be about equal.

[cpdaman]

http://www.ssd.noaa.gov/goes/east/carb/loop-wv.html

going to be a interesting 12 hours for our HANNA IMO

here's why

the ULL appears to have stopped moving West, in fact in the last two frames you can see it sink south

hannah appears to be continuing WNW so getting a bit closer again (although should finally get north since the ull is moving south now)

however the biggest problem i see for hanna out of this .....is that should the ull drop a bit more south she will begin to entrain a bit more of gustav's outflow which will strengthen her SE side and increase the South and South west shear over hanna later this morning and this afternoon, so i am watching for gustav' inflow to become more entrained to the ULL that is now sinking south (not west anymore) which would be a likely precursor to increasing shear over hanna in about 6 hours.

[cpdaman]

appears to be something

near 21.5 62.3/.4 would this be pretty much wnw from when it was last seen prior to visible=

partially exposed with a lil convection trying to build on east side of LLC

http://www.ssd.noaa.gov/goes/flt/t2/loop-vis.html

yes it's the LLC! you can't tell me that vigoruous spin we saw last evening dissapeared last nite in moderate south shear

thunder don't you see it on the visible again near 21 (or a hair north) 62.4

looks like a fairly vigorous spin still

the SSE outflow from t-storm to the south appears to make it difficult to seperate the low cloud spin, from the high cloud cirrus

[jlauderdal]

That would be a big shift back to the SE and given the set-up we have...would relaly bring the Caribbean into play given the WSW/SW motion the models are progging.

Not necissarily...

If the ridge is forecast to be in position A and the storm is farther north it will push it to position C. But if the storm is farther south than its projected north position the ridge will still only be able to push it to Position C. The difference should be very minor, based upon the center of the ridge axis... the force should be about equal.

eric, where does position B fit in this equation?

[KWT]

Got to admit I can't see any LLC there either, I don't think this has a LLC anymore either, though with such explosive convection further SE it could reform there.

[cpdaman]

i think it will become clear in the next hour or so , when the high cirrus from the t-storms to the south allow the vigorous low cloud spin to be identified in successive frame easier.

at 21.0 62.3 on the 1015 frame you can see what looks like a tight litte swirl

[cpdaman]

how's that

http://manati.orbit.nesdis.noaa.gov/dat ... MBas19.png

two hours ago

[AJC3]

There's definitely a LLC. Difficult to see, but it's there. I'll post a vis time lapse of it in a sec.

Coming into view near 21.5 62.5 (quick eyeball fix) beneath some CI just west of a convective blowup.

tried to make it as small as possible, but it's still over 1MB long...

http://home.cfl.rr.com/tcrist/images/LLC.gif

[gatorcane]

Question where is the center located?

I can't tell.

Definitely not west of the convection, and probably not under the convection. I.E., it doesn't appear to have one. But I think it'll redevelop under the convection over the next 24 hours.

Wxman I disagree, once some more visibles come in I think we'll see the center on the western edge of the concentrated blob at about 22N, 62W..still getting sheared by westerly shear. I see a movement of WNW to NW.

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

oh...wait looks likes AJC3 just said something similar above

[cpdaman]

Question where is the center located?

I can't tell.

Definitely not west of the convection, and probably not under the convection. I.E., it doesn't appear to have one. But I think it'll redevelop under the convection over the next 24 hours.

Wxman I disagree, once some more visibles come in I think we'll see the center on the western edge of the concentrated blob at about 22N, 62W..still getting sheared by westerly shear. I see a movement of WNW to NW.

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

oh...wait looks likes AJC3 just said something similar above

gator it's clear , its closer to 21.1/or 21.2 N at 62.3 W on the last frame it comes into focus plus add the quikscat and it's a no brainer..........it's also moving wnw and not gaining much latitude in the last 12 hours at all

[tgenius]

So if I understand this correctly, the more WNW Hanna goes vs NW would make her gain less lattitude, which could then make it a bigger threat for SE FL?