ATL HANNA: Models Discussion

[artist]

Latest NHC track is EAST and no "H" showing H=Hurricane.

in their extended it shows 75 kts, thus a hurricane -

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 225 NM
ON DAY 4 AND 300 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 04/0000Z 24.5N 74.5W
MAX WIND 55 KT...GUSTS 65 KT.

OUTLOOK VALID 05/0000Z 26.5N 76.5W
MAX WIND 60 KT...GUSTS 75 KT.

Those are gusts. The sustained wind forecast is for 60 knots at hour 120...which would be a tropical storm.

Nothing wrong with my reading!

[jinftl]

Also mentions the 300 nautical mile error average for the Day 5 position.

300 miles from the 'black line' means no one should let their guard down yet.

Latest NHC track is EAST and no "H" showing H=Hurricane.

in their extended it shows 75 kts, thus a hurricane -

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 225 NM
ON DAY 4 AND 300 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 04/0000Z 24.5N 74.5W
MAX WIND 55 KT...GUSTS 65 KT.

OUTLOOK VALID 05/0000Z 26.5N 76.5W
MAX WIND 60 KT...GUSTS 75 KT.

[artist]

yeah, unfortunately, I am afraid we in S Fl will be watching this all week.

[Evil Jeremy]

GFS coming in. WNW through first 24 hours

http://www.nco.ncep.noaa.gov/pmb/nwprod ... /fpc.shtml

[meteorologyman]

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.[/quote]

This from observation. Hanna looks weak, though models say she may be big, however nhc says the models are over doing it.

There are rumors that Gustav could shear Hanna 3 days from now after hanna intensifies a little, but I feel optimistic about that. Gustav approches LA in 2 to 3 days before landfall it is forecast to weaken do to the shear from the high. If that's the case Gustav could lose it's size as well, and beause of it's smaller size and less far reaching winds it may not effect Hanna. especially since both are going NW and both may stall at same time, though Hanna is moving more W where Gustav is moving NW, so Gustav is moving farhter away as we speak, so in this case i kind of trust the intensity forecast on the models. (just my opinion) As far where this thing goes, I'm as confused as the models

any thoughts are appreciated.

[umguy]

From reading the discussion it seems like 2 or 3 things have to happen for it to take this track. So I guess it all comes down to timing. So I believe it's still more of the wait and see game.

[Evil Jeremy]

Stalls for a few days, but it appears that Hanna starts to drift westward in 84 hours. I come to this conclusion by looking at the top right frame in the four panel charts:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... /fpc.shtml

[meteorologyman]

Hanna whatever you do.....don't you dare stall and try to prove something to Gustav or I will have put on my scary costume and scare you away.

Sorry for being silly had to get it out of my chest.

[Steve H.]

through 96 hours, the GFS is a bit west of its 18z run, and a hair further south.

[Bocadude85]

looks like another carolina run to me.. though the nw motion seems to starts a little later then the last time.

[Evil Jeremy]

drifting to the NW at 108 hours.

[jaxfladude]

Why do I have this feeling that my area may get a direct impact from Hanna and not a:
"Whew good for my area, bad for Savannah north to the SC/NC state border?"
With what the shape of my area's coastline?
Come on models get your acts together and correctly forecast a out to sea TS/hurricane Hanna...

[Bocadude85]

well if you believe the GFS Hanna will sit in the bahamas for 4 days before heading for the carolinas

I dont really believe anything the models are doing after 3 days now and Im not sure I even trust the 3 day forecast.. this is a complicated situation and im wondering if the models are picking up on Hannas weird interaction with the ULL.. maybe Im wrong I just find it weird for a storm to stall for 4 days and not move.. but what do I know

[Evil Jeremy]

I am not buying the stall, and it does not look like the NHC is buying it either, although it does slow Hanna down. Indeed, I only think the first 3 days of the models are reliable at this point.

[Bocadude85]

I am not buying the stall, and it does not look like the NHC is buying it either, although it does slow Hanna down. Indeed, I only think the first 3 days of the models are reliable at this point.

well we shall see because according to the models Hanna will come to a dead stop at about 71w which she should reach tomorrow... so we will see if she slows and stalls or keeps going off to the west

[Jinkers]

tomorrow all the models will be different again--know one knows where it's going

[Patrick99]

I don't buy any of these tracks......so let me get this straight. Forecasting all this northerly shear, yet this storm is going to turn right into the teeth of it? Why? What happened to the big high?

[umguy]

Well at least we all agree. I thought I was going crazy and the only one who was thinking this.

[ericinmia]

I love this, I can't even read the timing on where the storm will be since it just sits there meandering (sp?) around in circles...



Here is a loop...
http://moe.met.fsu.edu/mm5/h500.d1-merge.html

The idea there is the thing I'm hoping against (as much as I would like to test out my new weather station). It appears that Hannah bobs south in her meandering and gets pulled slightly north in toward the end of the run, only for the trof to begin to lift and and be replaced by a "somewhat weak" high pressure ridge, which appears to give a slightly more west direction to Hannah's motion. It really will come down to timing, and the strength/depth of these features.
-Eric

[AJC3]

I don't buy any of these tracks......so let me get this straight. Forecasting all this northerly shear, yet this storm is going to turn right into the teeth of it? Why? What happened to the big high?

I'll refer you to a post I made several pages back.
viewtopic.php?f=59&t=102684&st=0&sk=t&sd=a&start=480

The inconsistency I am talking about is in the model consensus. This time yesterday, the spaghetti models had the turn to the SW towards the Cuban coast (at least in that direction) which would translate to missing the east coast of Florida and probably going through the Florida Straights or The Keys. 24 hours or so later, models seem to indicate a turn before the East Coast of Florida and a threat more to The Carolinas.

Being an amatuer, I read this to be a change in the philosophy of the upper air pattern showing an expected weakness that did not exist 24 hours ago.

The shear from the N-NW was progged to be severe (35-40 mph) and that seems to be unchanged.
But, would a storm head TO the NW with shear coming FROM the NW??

If the mean steering level layer flow (e.g. centered around H50) was steering it that way...then yes, there's no reason that it could not push it NW into the teeth of a H25 jet. The shear would rip it apart, but that happens sometimes, especially when one TC is trailing another. In fact...that's precisely what I saw in the guidance this morning.

I never had a problem with the models being inconsistent...I had a huge problem with them making meteorological sense (i.e. intensification in the teeth of a strong upper jet.)

If the predominant steering flow, centered at the mid levels (500MB) steers a system toward the WNW or NW, and the upper level flow (250 MB) flow is from the NW and N, that can happen. I've seen this on several occasions, though mainly in the deep tropics when a WNW system is following another, whilst getting hammered by the outflow. There's a great example of this from the late 90's or early 00's...I'll try and dig it up.