ATL HANNA: Extratropical - Discussion

[cpdaman]

11pm discussion discussed how gustav's outflow was keeping the ULL low from weakening and moving SW to much and that the relatively new northerly shear over gustav should decrease this inflow and allow ULL to weaken and move sw like previously forecast. WE SHALL SEE by 230 am when the satellite eclipse is over how things look.

interesting tidbits in the 11pm discussion if you have not read the whole thing

http://www.nhc.noaa.gov/text/refresh/MI ... 0259.shtml

[eastcoastFL]

very interesting discussion. I think hanna could become a very large storm and keep us all on our toes for the next week.

[Vortex]

00z hwrf takes hanna down to 887mb and 160 mph..stalls then heads ne...most all the guidance now is developing a very strong and large hurricane.

[Scorpion]

Yes that HWRF is just beyond ridiculous, but the CMC is also showing this. Pretty crazy.

[Matt-hurricanewatcher]

00z hwrf takes hanna down to 887mb and 160 mph..stalls then heads ne...most all the guidance now is developing a very strong and large hurricane.

There is only a few area's with in the Atlantic that can do that 1# western Caribbean where Gustav is entering 2# Southeast of Florida around 20-25 north 78-84 west 3# Loop current of the gulf of Mexico. Now it could come into the edge of 2#, but that would need a perfect set up...Much more likely Gustav gets that strong over the much more powerful TCHP of the western Caribbean.

[Vortex]

00z ukmet heads towards the fl straits and and 00z gfdl heads due south in the long range. Since the euro was the first model to suggest the sw turn and has been consistent I'm anxiously awauting the 00z run.

[Vortex]

00z hwrf takes hanna down to 887mb and 160 mph..stalls then heads ne...most all the guidance now is developing a very strong and large hurricane.

There is only a few area's with in the Atlantic that can do that 1# western Caribbean where Gustav is entering 2# Southeast of Florida around 20-25 north 78-84 west 3# Loop current of the gulf of Mexico. Now it could come into the edge of 2#, but that would need a perfect set up...Much more likely Gustav gets that strong over the much more powerful TCHP of the western Caribbean.

agree but the point im taking from the overnight runs is that hanna looks more and more like she will have a a good shot at becoming a major hurricane.

[Scorpion]

I'm wondering if this may become a WPAC Ivan and Joan scenario, with two extremely powerful hurricanes churning at the same time.

[Vortex]

00Z Euro and yet another run and another hit for southern florida..This is becoming more than a trend at this point. Very consistent the last several runs with very small deviations between days 3-6.


http://www.ecmwf.int/products/forecasts ... 00!!!step/

[Matt-hurricanewatcher]

If Gustav becomes a cat4 or cat5 hurricane its outflow jet(Anticyclone) will spread shear over this. I've seen it happen many of times, any systems within 1,000 miles to the east or northeast normally feel the down stream shear. So this might have to wait for Gustav to weaken. Something to think about.

[wxmann_91]

I think the bigger problem Hanna will have is that the midlatitude low to the north will drag down a large continental high. This occurs at the same time the models ramp up shear, and of course let's not forget upwelling problems. So as for right now I think it might strengthen decently up to around 96 hr and then weaken back down quite rapidly. After that... too early to tell.

[KWT]

Hanna still blowing up lots of convection on the eastern side and where the convection is still being sheared its holding onto the LLC much better then it was 18hrs ago showing shear has eased off, very interesting convective blow up should allow some slow strengthening if it holds.

[Thunder44]

I think I see the LLC on IR2 coming out west of the convection near 21N 62W. Anyone else see it:

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

[jlauderdal]

00Z Euro and yet another run and another hit for southern florida..This is becoming more than a trend at this point. Very consistent the last several runs with very small deviations between days 3-6.


http://www.ecmwf.int/products/forecasts ... 00!!!step/

oh vortex, you just want to get the south florida hype machine rolling

[Squarethecircle]

00z hwrf takes hanna down to 887mb and 160 mph..stalls then heads ne...most all the guidance now is developing a very strong and large hurricane.

Though you must remember that the HWRF has a very, very nasty habit of seriously overestimating pressure-intensities. Many runs have such oddities as sub-940 2s, and sub-920 3s.

[KWT]

The wind pressure from the HWRF isn't really wise to use, its the winds to watch.

Anyway vis imagery coming through now, will be interesting to see if the center is getting exposed or not.

[captain east]

Does South East Florida have a good chance of being hit?

[jlauderdal]

The wind pressure from the HWRF isn't really wise to use, its the winds to watch.

Anyway vis imagery coming through now, will be interesting to see if the center is getting exposed or not.

isnt there some correlation between central pressure and winds?

[HURAKAN]

[tgenius]

The bit that concerns me is NHc is starting to acknowledge that the models are taking the SW turn but are hesitant to show it in the 5 day cone; If the model runs through the weekend keep with that, I don't think they will have much of a choice in the matter