ATL HANNA: Extratropical - Discussion

[Blown Away]

I think we are 2 advisories away from seeing Hanna's forecast track start making a W or WNW turn from that SW movement. I just will be very surprised if Hanna tracks SW over Cuba. IMO, Hanna will begin the WNW-NW movement long before she makes it to Cuba.

Certainly this is a case where extrapolating the cone beyond the 5 days shown assuming it will just be an extension is not prudent yet is done erroneously. Given model runs beyond the 5 day cone, one would expect to see the bend back to the W and then WNW and I agree we are within a few advisories of seeing this bend.

But it would appear that the shear forecast is a good sign, if it verifies and even if Hanna makes it to South Florida, it may just be a CAT 1 hurricane or tropical storm, no picnic but better than a major hurricane.

From NWS Melbourne: PREVIOUS EXTENDED DISCUSSION...
TUE-FRI...FCST REMAINS VERY UNCERTAIN AND HIGHLY DEPENDENT UPON THE TRACK AND STRENGTH OF HANNA. ONE TREND NOTED ON THE MORE RELIABLE GLOBAL MODEL GUIDANCE IS THAT THE UPPER LEVEL PATTERN BECOMES QUITE
HOSTILE FROM LATE MONDAY ONWARD OVER THE WESTERN SARGASSO SEA AREA ...WHERE HANNA IS FCST TO BE..AS A 40-50KT NNW-N JET IS FCST TO DEVELOP ON THE EAST SIDE OF THE ERN CONUS DLM RIDGE. THIS IS
REFLECTED IN SIGNIFICANT SLOWING IN FWD SPEED ALONG WITH A TURN TWD THE SW...AND A REVERSAL OF THE INTENSIFICATION TREND...BY MON-TUE. WE WILL CONTINUE TO WATCH THE PROGRESS OF HANNA CLOSELY HERE ALONG
THE EAST COAST OF FL.

Derek & Accuweather both are predicting a cane after 5 days. The NWS Melbourne talks about the strong upper level winds in the "Western Sargasso Sea Area", to me that does not include the SE Bahamas. So if Hanna gets into the SE Bahamas she may be far enough from these winds to allow strengthening. Some of the models seem to bring a strong system near SFL.

[cpdaman]

I agree that the LLC is just to the right of that eddy where the convection is firing. To me you can see the inflow moving toward the convection. The gray barely visible clouds in this horrible IR2 shot.

no way no how IMO the LLC was clearly visible at 64 west a few hours ago moving West fast, it died

what ever is under that blob would be an MLC

and since it's SE of the ULL it will be in a rather poor enviornment unless it moves north or drifts at 2 mph or less

Well we're both wrong I think.



Loop:
http://hadar.cira.colostate.edu/ramsdis ... at1_0.html

IR2 without any crappy enhancement. You can see the LLC remains 65W 21N or there about. This would not be showing an MLC. The LLC moved a bit south in the loop.

In that loop the LLC seems as if it is being drawn back into the convection or the convection is catching up to the LLC[/quote]

pressure down to 29.64 literally sitting right next to bouy

http://www.ndbc.noaa.gov/station_page.php?station=41043

yes tolakram i noticed that around 1030 pm right BEFORE my internet lost connection when a strong thunderstorm came thru boca raton, i knew that was the LLC, (you could see the inflow but just vagely with the crap ir2, but i thought the SW dive motion would continue, ON ir2 you can see the llc turned back a bit SE and has since began drifitng erratically at 21.3/ 65.0 right past the western edge of convection.

stayin alive

very interesting to me that the LLC was racing all day, bounced Sw, then SE then stalled for an hour and now drifting .........who the heck knows what it will do next

[Bocadude85]

LLC seems to be going back under the convection now

[Dean4Storms]

yep, the LLC stopped and has drifted S to SSE from what I see.

[cpdaman]

LLC seems to be going back under the convection now

yes for now so long as the LLC doesn't decide to race west again

http://metofis.rsmas.miami.edu/~dortt/s ... 1_loop.gif check out that wv loop , ULL is still having it's sweet way with hanna (blasting her on the ull's SE side with SW shear) hanna can't get above the ULL's latitude yet....another long day saturday

the path south of an ULL is never a good idea ( shear in yo face)

[gatorcane]

That latest GFS 00Z run shows Hanna approaching the SE Coast of Florida and then recurving just before landfall -- big difference in this run because the SW dip is even less pronounced.

and some more good news is that the GFS upper-level wind forecast shows strong shear for Hanna.

[cpdaman]

anyone wanna have an idea of where hanna is during the eclipse

can watch the winds at the bouy that is almost on top of her

sw sustained at 27 w gusts to 33 knots

pressure down to 29.62

http://www.ndbc.noaa.gov/station_page.php?station=41043

[Bocadude85]

That latest GFS 00Z run shows Hanna approaching the SE Coast of Florida and then recurving NW just before landfall -- big difference in this run because the SW dip is even less pronounced.

and some more good news is that the GFS upper-level wind forecast shows strong shear for Hanna.

well the shear part is good news but a tiny deviation to the left would bring her ashore... lol and again we are looking at a landfall point 6 days out we all know this wont verify

[gatorcane]

Well the 00Z GFS is interesting. It ultimately curves Hanna away from Florida and up to the Carolinas. It shows a deep short-wave trough moving through the CONUS around 130-150 hours in this run.....which is telling me that the longer Hanna hangs around in the Atlantic she may get picked up by a trough sooner than later...

we need to see trends though.....to be convinced.

[Bocadude85]

[quote="gatorcane"]Well the 00Z GFS is interesting. It ultimately curves Hanna away from Florida and up to the Carolinas. It shows a deep short-wave trough moving through the CONUS around 130-150 hours in this run.....which is telling me that the longer Hanna hangs around in the Atlantic she may get picked up by a trough sooner than later...

we need to see trends though.....to be convinced.[

we just need to look at trends in general.. the models show her diving sw and adventually moving back to the wnw.. also the NHC stated that models have had a right bias with Hanna

[curtadams]

LLC is not under the convection area but I agree it's been pulled back. It put up some convection of its own just before eclipse started. When eclipse ends we'll find out whether it regenerated convection (like yesterday) or had it sheared off (like today).

[cpdaman]

LLC is not under the convection area but I agree it's been pulled back. It put up some convection of its own just before eclipse started. When eclipse ends we'll find out whether it regenerated convection (like yesterday) or had it sheared off (like today).

well at least the bouy it's sitting over can tell you some stuff as the eclipse continues for another 90 min or so

[eastcoastFL]

what eclipse?

[cpdaman]

what eclipse?

every nite there is a "satelite eclipse" from about 1215 to 215 am, not some kind of lunar/solar eclipse

[eastcoastFL]

i never knew that

[eastcoastFL]

new GFS run brings hanna into florida than makes 2nd landfall in SC

[RL3AO]

i never knew that

It only happens during the 4 weeks (or so) before and after the spring and fall equinox. The satellite moves into the shadow of the earth for a few hours and since its solar powered, it stops working.

[eastcoastFL]

pretty neat

[BigA]

Somehow the center seems to have been sucked to the east toward the convetion, at least per the Colorado State infrared.

[cpdaman]

Somehow the center seems to have been sucked to the east toward the convetion, at least per the Colorado State infrared.

negative..still slightly NW of this bouy at 21/65 west

http://www.ndbc.noaa.gov/station_page.php?station=41043

note the wind direction

could you post a link though