ATL: ISAAC - Post-Tropical - Discussion

[otowntiger]

It continues to confirm what NHC mentioned in their 09Z discussion:

WHILE THE 850-MB FLIGHT LEVEL CENTER WAS WELL SOUTH OF THE PREVIOUSLY ESTIMATED SURFACE CENTER LOCATION... DROPSONDE DATA SUGGEST THAT THE SURFACE CENTER REMAINS FARTHER NORTH.

I would add that with a ENE wind at 23 kts at the sfc...and a 998 pressure...we probably have a sfc center down near the 700mb center...near 15.8 / 70 and a pressure closer to 996.

It's about to go...

by saying "It's about to go" do you mean it's finally ready to start intensification? That would not be good this close to populations. Hopefully it stays a mess and doesn't get its act together.

[Snowman67]

It's going to have to take a sharp right turn to hit Haiti. Center is well south of the 06Z model tracks.

Wxman57 - do you think it will track closer to Jamaica than Haiti? If so, do you feel that this would change its eventual U.S. projected landfall location? Thanks.

[robbielyn]

i see alot of eastern gulf dry air and ull western gulf could affect strength

[Blown Away]

Well, I have been staring at the satellite loops for past few hours and I'm not seeing Isaac moving that much, the broad circulation has been hugging that 70W line for a while. Moving at 15mph is noticeable when watching the loops IMO.
http://www.ssd.noaa.gov/PS/TROP/floater ... -long.html

[BensonTCwatcher]

Outflow pattern on the west side as noted by Sanibel, indicates upper air conditons improved. Looks like once the dry air on the east side is overcome by the developeoing heavy convection it will likely intensify further. Prob 4-6 hours at least to get that done. Can clearly see yesterday's MLC that was centered near 15N "pulled in" the LLC to the NE. Still "tilted" a bit but def. looks linked.

http://www.ssd.noaa.gov/PS/TROP/floaters/09L/flash-vis-long.html

[KWT]

Well motion according to recon is 305, so if that motion continues its a close call as to whether it hits Haiti.

Worth noting a decent shift in winds is alos found nearer the NHC location.

[Blown Away]

Well motion according to recon is 305, so if that motion continues its a close call as to whether it hits Haiti.

Worth noting a decent shift in winds is alos found nearer the NHC location.

I think we finally have a more concentrated circulation that is tightening up near the NHC's spot.

[Hurricane Andrew]

Recon has found FL winds of over 70mph.

[brunota2003]

Looking at everything...looks like the center is near 15.7N, and I expect this afternoon's recon flight is going to look so different that you'll be wondering if they are flying into the same storm! Convection is starting to wane at the moment, but I expect it to refire, especially this afternoon. Right now, I think it is giving up energy to reorganize, and then once that is complete (or close to it), look out! Starting to see signs RI may be on the not so distant horizon, unless it somehow gets pulled over land in the next 12 to 24 hours.

RI at this point would put it as (at least) a 75 knot hurricane by 8 am tomorrow morning (RI is considered as a jump in wind speed of at least 30 knots in a 24 hour period). It looked like the indicator I usually use was starting to appear around 6 am, which would put the "snap together" around 12 pm to 2 pm EDT...the only thing is, I'm not confident it'll make 30 knots by tomorrow morning...because of the lack of organization it would have to fight through prior to being able to take off, along with any possible land interaction...best bet would be to hedge at 20 knots currently, until we see what this afternoon brings.

My forecast:

Between now and 8 am tomorrow:
Peak wind speed of 65 knots
Peak wind speed of at least 75 knots possible, barring land interaction and depending on how quick it manages to pull the rest of the way together.

Personal Forecast Disclaimer:
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.

[Hurricane Andrew]

Recon has found 65kt FL winds.

[BensonTCwatcher]

Recon has found 65kt FL winds.

what does that factor down to? Sorry, forgot the reduction...

[Hurricane Andrew]

Recon has found 65kt FL winds.

what does that factor down to? Sorry, forgot the reduction...

They found SFMR of over 60mph.

[Caribwxgirl]

I think I can understand the NHC's reasoning for maintaining the track as is. The truth is they have an an obligation to the people of the USA to keep them on their guard. These systems can be quite erratic as such if they were to change the track and people stop preparing and then it swings back toward the original track at short notice then the NHC would be really in for it. So I guess it's best to play it safe until they are absolutely sure.

Just my opinion

[Air Force Met]

It continues to confirm what NHC mentioned in their 09Z discussion:

WHILE THE 850-MB FLIGHT LEVEL CENTER WAS WELL SOUTH OF THE PREVIOUSLY ESTIMATED SURFACE CENTER LOCATION... DROPSONDE DATA SUGGEST THAT THE SURFACE CENTER REMAINS FARTHER NORTH.

I would add that with a ENE wind at 23 kts at the sfc...and a 998 pressure...we probably have a sfc center down near the 700mb center...near 15.8 / 70 and a pressure closer to 996.

It's about to go...

by saying "It's about to go" do you mean it's finally ready to start intensification? That would not be good this close to populations. Hopefully it stays a mess and doesn't get its act together.

Yes...I mean it should start to strengthen.

[Sanibel]

The outflow on the west side could be the result of a burst finally kicking the engine in to gear. There's slightly improved curvature going towards the center now too. It might be finally strenthening, or it might be a pulse. The problem is still lingering synoptic shear of an Atlantic dry airmass to the NE quadrant.

[ozonepete]

Hi guys this is my first post since finally being able to join, i had to wait nearly 24 hours since signing up to post ! Oh well !!...
...Time will tell, and I will be watching this like a hawk, I hope everyone in the path of Isaac stays safe and starts there Hurricane Preperations now just in case.

Cheers - Travis. ( Aussie Cyclone Chaser )

Welcome Travis. Enjoy the action with us. There's a lot of sharp people on here.

[Hurricane Andrew]

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.

My new forecast.
0 Hours, 45kts
12 Hours, 55 kts
24 Hours, 55 kts
48 Hours, 50 kts
72 Hours, 60 kts.
Thoughts?

[Blown Away]

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.

My new forecast.
0 Hours, 45kts
12 Hours, 55 kts
24 Hours, 55 kts
48 Hours, 50 kts
72 Hours, 60 kts.
Thoughts?

IMO, winds could be much higher if less land interaction, but I know you are taking that into consideration w/ your forecast. Like to know your thoughts on track, make sure you check out 12z run, big shift east. IMO Isaac will be a Florida peninsula storm!

[Hurricane Andrew]

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.

My new forecast.
0 Hours, 45kts
12 Hours, 55 kts
24 Hours, 55 kts
48 Hours, 50 kts
72 Hours, 60 kts.
Thoughts?

IMO, winds could be much higher if less land interaction, but I know you are taking that into consideration w/ your forecast. Like to know your thoughts on track, make sure you check out 12z run, big shift east. IMO Isaac will be a Florida peninsula storm!

I have seen the shift east. For now, I will go with a track into extreme southwest Haiti, then through NW Cuba, and into the gulf, close to the coast.

[hurricanes1234]

Looking good.