ATL: ISAAC - Models

[northjaxpro]

978 mb is really not that significant intensity wise.. that is a cat 1..I know GFS is not a reliable intensity scale, but it amounts to something

978 mb can translate to support a Cat 2 cyclone, which is potent storm. Also, of course any tropical cyclone in the GOM can easily intensify to major status, especially given the current sea surface temps there and if the cyclone has very conducive enviromental conditions.

[Dean4Storms]

Mobile, NWS explanation of the discrepancies.......

LONG TERM...(FRIDAY NIGHT ON)FRIDAY NIGHT BEGINS WITH ISAAC APPROACHING
CUBA...AROUND THE BASE OF AN UPPER RIDGE OVER THE WESTERN
ATLANTIC...OFF THE CAROLINA COAST. A WEAKLY ORGANIZED UPPER SYSTEM
OVER THE CAROLINAS...AN UPPER RIDGE STRETCHING EAST OVER MEX TO THE
WESTERN GULF OF MEX. ITS A WEAK UPPER TROUGH OVER THE EASTERN GULF OF
MEX THAT IS MAKING FOR AN INTERESTING FORECAST IN THE EXTENDED. THE
GFS/NAM/CANADIAN MAINTAIN THIS UPPER TROUGH OVER THE EASTERN GULF
INTO THE WEEKEND...ALLOWING ISSAC TO MOVE NORTH OVER THE FL
PENINSULA. THE ECMWF BUILDS THE WESTERN ATLANTIC RIDGE WEST...OVER
THE GULF OF MEX...STALLING ISAAC OVER CUBA THROUGH THE WEEKEND.

[meriland23]

978 mb is really not that significant intensity wise.. that is a cat 1..I know GFS is not a reliable intensity scale, but it amounts to something

978 mb can translate to support a Cat 2 cyclone, which is potent storm. Also, of course any tropical cyclone in the GOM can easily intensify to major status, especially given the current sea surface temps there and if the cyclone has very conducive enviromental conditions.

I am curious if it ends up in the gulf, if the north and eastern side of the cyclone are on land (like gfs shows this time around) wouldnt that only maintain or weaken the system?

[Mouton]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org. For Official Information please refer to the NHC and NWS products.

The latest GFS run is consistent with most of the ensamble's solutions from an earlier run. IMO, for whatever reason it put more weight on those on the left side verses those on the right side this time.

I am going to stick with my path guess of yesterday morning:

"I don't see any future steering paterns that would force a Charley like turn either which is why I am content with a slow curvature perhaps over the GOM side of Florida, just how far up the coast or into the Panhandle I have no idea. Outside guess would be over Key West and re-land near Panama City or appolachiacola."

One thing I am happy to see, it appears we may actually have a no rain day here today in NE Florida. However, should this storm get here next week, the ground is already saturated so even with out major force winds, there is going to be a lot of havoc.

One thing that should trouble the entire Florida peninsula is the NHC's personnel do an excellent job with these storms and their consistency of showing a SFL hit along with their virtually doubling down in their 5am discussion today is worrisome for those on the east side of the peninsula dispite my above ramblings.

[northjaxpro]

978 mb is really not that significant intensity wise.. that is a cat 1..I know GFS is not a reliable intensity scale, but it amounts to something

978 mb can translate to support a Cat 2 cyclone, which is potent storm. Also, of course any tropical cyclone in the GOM can easily intensify to major status, especially given the current sea surface temps there and if the cyclone has very conducive enviromental conditions.

I am curious if it ends up in the gulf, if the north and eastern side of the cyclone are on land (like gfs shows this time around) wouldnt that only maintain or weaken the system?

If this was the case, the center of the tropical cyclone would still be over open water. It would still be able to potentially intensify. Also, the north and east quadrants of a cyclone are always the worst sides of the cyclone. In this situation, should Isaac get into the Gulf and approach the peninsula from that side, then major problems with storm surge would be occuring along the Gulf coast of the peninusla, with the biggest concern being up in the Cedar Key area which is extremely vulnerable to storm surge. Also. on land, heavy rain, inland flooding potential and squalls with the potential small scale tornadoes would also pose a significant threat as well. Also, a powerful easterly wind fetch from off the Atlantic would cause havoc on the East Coast of the peninsula. It would be an absolute mess across the entire peninsula.
_______________________

The posts in this forum are NOT official forecast. They are just the opinion of this poster. For official information, please refer to the NHC and NWS products

[Nimbus]

Only thing that caught my eye in the water vapor imagery this morning is that there is an anticyclonic circulation over the gulf of Mexico that looks like it might bridge with the dome Isaac is starting to build. There is a weakness swinging through Mississippi north of that, but doesn't look like it will necessarily dig. Timing of a second short wave after that might dictate landfall.

GFS has Isaac moving quite slowly as it passes west of Tampa. A stronger ridge might even create a stall with a track slightly more left, a weaker ridge would steer the track right closer too or over the west coast of Florida.

I'm still thinking a landfall somewhere along the Florida panhandle. Telling the Media to wait till Friday for an accurate track is kind of problematic. Tough decisions on where to run the 5 day cone, and there is real danger for Haiti and Cuba in the shorter term.

[tolakram]

Global roundup, 96 hours

[tolakram]

6Z run GFS, 96 hours

[CalmBeforeStorm]

Through 96 hours the Euro's weak and left with Issac, the GFS is stronger and in the middle, the CMC is the strongest and to the right.
I think it is obvious Issac's strength through 96 hour determine's where in the cone it ends up. I see a tropical storm coming into the Caribbean in late August, low shear forecast in it's path, heat content high and forecast to rise and it's speed not as fast as previous storms this year and forecast to slow. I think Issac will be stronger and on the right side of the guidance.

[blp]

90hr 06z Hwrf further west than 00z. I smell a west shift today with the models.
http://raleighwx.americanwx.com/models/ ... est090.gif

[Blown Away]

Through 96 hours the Euro's weak and left with Issac, the GFS is stronger and in the middle, the CMC is the strongest and to the right.
I think it is obvious Issac's strength through 96 hour determine's where in the cone it ends up. I see a tropical storm coming into the Caribbean in late August, low shear forecast in it's path, heat content high and forecast to rise and it's speed not as fast as previous storms this year and forecast to slow. I think Issac will be stronger and on the right side of the guidance.

Good summary, that is what the models are saying and it's difficult to see Isaac not getting stronger:
Weak = Left left side of cone
Strong = Right side of cone

[Jevo]

With the way that the models have been windshield wiping across the peninsula over the last 3 days I don't expect you will see any major shifts in track forecast until the NHC has the G-IV data in the models tomorrow night. Right now all of the models except for the Euro are well within the 5 day cone

[CalmBeforeStorm]

http://raleighwx.americanwx.com/models/ ... MSL054.gif

The GFDL is stronger earlier in the 6Z run and takes Issac into the east side of the DR. Stronger storm, right side of guidance.

[Stormlover2012]

its all going to be about timing with the trough and etc

[Javlin]

Looking e coast of FL with the GFDL @96hrs





http://raleighwx.americanwx.com/models/ ... MSL096.gif

[CalmBeforeStorm]

http://raleighwx.americanwx.com/models/ ... MSL102.gif

6Z GFDL definitely stronger and to the right of the previous runs. Looks like a S. Fla hit on this run.

[CalmBeforeStorm]

http://raleighwx.americanwx.com/models/ ... lLoop.html

6z GFDL sends Issac right up the Eastern Florida coast as a strong storm.

[Javlin]

Well a pattern is starting to lay itself out on the GFS runs it seems 06z/18z go left 00z/12z right.It use to be in the past you paid attention to the 00z/12z for I think they got new data have to see if any of the mods can substantiate that for me?

[sphelps8681]

Does anyone remember when the euro was by itself with a preiction that came true and the others shifted towards it.

[Portastorm]

Does anyone remember when the euro was by itself with a preiction that came true and the others shifted towards it.

I know what you're getting at here ... wondering if the Euro is going to score a model coup. Is it possible? Sure. Should anyone in the central or western Gulf take their eyes off Isaac ... absolutely not! But the prevailing conventional model wisdom still suggests Florida as the most likely US mainland hit. King Euro stands by himself at the moment.

And in terms of globals, the Euro continues to outperform the GFS although the latter seems to be much improved this summer.