ATL HANNA: Extratropical - Discussion

[karenfromheaven]

What is Stacy Stewart referring to in his 5AM discussion, when he notes the some "automatic intensity plotting software" may cause the storm to appear to be weakening at landfall?

[cpdaman]

http://www.ssd.noaa.gov/goes/east/nwatl/loop-avn.html

gustav is shearing the heck out of her (like he turned a fire hose on her) the divergent flow of shear that yesterday was splitting mostly east (as well as west) of her is now on top of her.

also note how fast the north shear is moving around the west side of the cutoff low east of new england.......wow...........

[ronjon]

LLC is drifting slowly west according to latest VIS SAT - it's exposed with convection sheared to the south and east. The LLC appears vigorous so I don't think it'll wind down anytime soon. Key to future forecast track is how far west Hanna drifts today before she starts the NW track. I know its the NAM, but its 06Z run showed a much weaker storm and the track shifted considerably south and west and brought the center much further south into Ft Laud in 72 hrs - maybe its on to something or maybe not - it is the NAM. Low level steering flow is a west movement.

[deltadog03]

She does look bad, but models did have this weakening today....

[HouTXmetro]

This storm poses no threat to the GOM right?

[cpdaman]

LLC is drifting slowly west according to latest VIS SAT - it's exposed with convection sheared to the south and east. The LLC appears vigorous so I don't think it'll wind down anytime soon. Key to future forecast track is how far west Hanna drifts today before she starts the NW track. I know its the NAM, but its 06Z run showed a much weaker storm and the track shifted considerably south and west and brought the center much further south into Ft Laud in 72 hrs - maybe its on to something or maybe not - it is the NAM. Low level steering flow is a west movement.

you know that vigorous LLC has been her hall mark

AJC3 (you have been a pro-met most interested and involved in this thread)

how do you see the evolution of the synoptic set up evolving and how does this effect your latest thoughts on track and intensity

[HURAKAN]

This storm poses no threat to the GOM right?

So far you're safe!

[storms in NC]

The TV news here are thinking a more move to the east is going to happen. And In to Wilm. And going by History I beleive that more than a Ga landfall. I see they have it were I said last night around Charlestion. So from Charleston to Cape Fear River

I havn't looked at her good this morning. So let me look and see what is going on.

[apocalypt-flyer]

This storm poses no threat to the GOM right?

Let's just say it won't get anywhere near Texas.

[KWT]

Indeed thats true Deltadog and the models dfo still suggest this wil lbe a strong system down the line.

However I think with such a slow drift its not a big deal whether the turn happens now or 12hrs down the line, the difference will probably be only around 30 miles further west. Of course for North Florida that may well make a big difference however if it does go NW.

[deltadog03]

The TV news here are thinking a more move to the east is going to happen. And In to Wilm. And going by History I beleive that more than a Ga landfall. I see they have it were I said last night around Charlestion. So from Charleston to Cape Fear River

I havn't looked at her good this morning. So let me look and see what is going on.

You can't really be sure of that...Neither can they. Thing is...IF** this starts to take longer to get out of bahamas, then the move should be more westerly...That ridge (forecasted) looks to be a monster.

[Frank2]

I was once told by an NHC forecaster that southward moving systems usually favor dissipation (in this hemisphere), and, it seems that is happening to Hanna...

And, the trough in the mid-Atlantic remains deeper than forecast, so, this might mean a recruve for Ike - if true, both would be good news...

[cpdaman]

I was once told by an NHC forecaster that southward moving systems usually favor dissipation (in this hemisphere), and, it seems that is happening to Hanna...

And, the trough in the mid-Atlantic at this time remains deeper than forecast, so, this might mean a recruve for Ike - if true, both would be good news...

i been wondering about that deep trough in the atlantic frank....."exit right ike"

back to hanna yes yes

FRANK 2 also look at a visible loop she is not moving south, she's moving west now

just the shear is pushing convection south

21.2 73.2 per visible

i think we have to look at east centrat cuba as a possible hit

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

[Blown Away]

Hanna definitely has a well defined LLC and it is already SW of the 2pm today NHC point.

[NEXRAD]

The upper level shear near and north of Hanna has ramped up further over-night, and is not likely to lessen today. In fact, the latest RUC/2 (along with the NAM) keep the shear strong, if not a little stronger, throughout the day before finally lessening up with it by early Wednesday. With such a pattern, the only area Hanna could retreat to for maintaining better central convection would be immediately near the Northeast Cuba coast.

Worth noting, the GFS builds even more impressive shear across the SW Atlantic through Thursday AM, though this seems to be in part feedback with the GFS handling of Hanna's circulation (reflecting it at H25). With a weaker Hanna this morning, the GFS might be overdone with the shear, for one, and for how it ultimately handles the storm.

- Jay

[KWT]

Good post Jay, the models all seem to suggest that the shear shouldn't ease off any time soon though there is still some disagreement about the shear levels and exactly when it does ease off.

[storms in NC]

She does look bad, but models did have this weakening today....

I want to Thank you for being here on Hanna. You will see not many will be here cause it is a SC_NC threat. You will not see 500+ pages on Hanna either. If Fla is out of Pic they seem to fall away and on to other ones. The east coast don't get the support Like Fl TX and the upper Gulf coast. It is ashame cause we give them the support.

On to Hanna I know it is going to be a tricky forecast to say the lease. So even the wobbles are going to be a big play in Hanna.

Thank you for all your help in the coming days

[Weatherboy1]

Most of the early morning models (GFS, GFDL, NOGAPS, etc.) appear to have shifted closer to the FL east coast, partially as a result of the S/SW movement in Hanna. She is clearly being sheared sharply at this point, with the LLC exposed at the NW corner of the main ball of convection. IF Hanna can survive or at least not weaken too much in the next 24-hour period of severe shear, it is possible the FL east coast gets more out of this storm than I expected when I went to bad last night.

[deltadog03]

NP and hey, hanna might effect me and my dma, so I have a lot of interest in this one.

[MBismyPlayground]

She does look bad, but models did have this weakening today....

I want to Thank you for being here on Hanna. You will see not many will be here cause it is a SC_NC threat. You will not see 500+ pages on Hanna either. If Fla is out of Pic they seem to fall away and on to other ones. The east coast don't get the support Like Fl TX and the upper Gulf coast. It is ashame cause we give them the support.

On to Hanna I know it is going to be a tricky forecast to say the lease. So even the wobbles are going to be a big play in Hanna.

Thank you for all your help in the coming days

At this point, with the shift west, do you think there is a reason now to worry??
With the new "trend" to the west and the shear and all....nothing will surprise me at all.Although you are right.... very few people even make the "self forecast" <shrug>