ATL: IRMA - Models

[TheStormExpert]

My money is shift west today just like yesterday. This is normal swings we see past 7 days. In the end the GFS will give the most ground due to its inherent trough bias We saw this with Harvey when GFS was showing North Florida for several runs which proved to be wrong.

The GFS never showed North Florida as a landfall destination for Harvey. You must be thinking of Cindy?

[TheStormExpert]

GFS/Euro consistent on blocking Irma from turning NE into Atlantic... I think that's what you take away from these model runs, seems that HP wants to be strong and block Irma, wouldn't surprise me if a southerly route into EGOM or a NE impact... I will always side with magic trap door opening at some point for last minute escape...

It makes we wonder if we could end up getting a Donna track out of this.

Donna went ALMOST into the extreme SE Gulf which at the moment seems unlikely. But you never know!

[AutoPenalti]

Nice to wake up to east shift, perhaps SE FL may be in the okay soon?

[TheStormExpert]

Several of the 00z EPS Ensembles now recurve Irma OTS after heading close or through the Bahamas. The operational run is on the far left side of the ensembles now. So expect east shifts which should also be good news for the mid-Atlantic and NE U.S. I think chances of a Florida strike a decreasing.

Be careful with statements like this, it's not always the case. This goes for everyone, predictive statements have no place here. Please be careful of projecting false expertise. Starting sentences with I WONDER or PERHAPS does a lot to make sure folks know it's an opinion. Many times this is just a wording mistake, nothing to get angry about, but let's just be extra careful please.

Sorry. I was just going by the overnight trends which seem to be coming in-line on a Carolina threat at the moment whereas the 18z GEFS Ensembles had Florida as the target landfall destination for whatever reason.

[blp]

Hmmmm!
Steering indicates a weakening of high pressure near 50-55 or not?

[img]http://tropic.ssec.wisc.edu/real-time/atlantic/winds/wg8dlm4.GIF[/]

You can't use these charts to predict future steering. These charts show current or prior steering. The high is moving and it will be different when the storm reaches that area.

[stormreader]

Not sure how much this matters in the big scheme of things, but my official NWS forecast for next Thursday and Friday has very unseasonable cooler weather. Highs low 80s and Lows low 60s and sunny. Located north central gulf coast.

Good post. The only fly in the ointment is that with those unseasonably cooler temps along the north central gulf coast, normally you might expect a hurricane to be swept out to sea, perhaps just off the northeast US and out into the open Atlantic. Instead the Euro has the storm being affected very late and turning only up into the S Carolina area. It's early, and I'd still be a little suspicious about the depth of that trough (cooler air coming down) in early Sept. It may very well pan out that way, or it may be overdone, and ridging north of Irma continues later into the forecast period than expected, allowing Irma to push farther west near S Fl and then the GOM. Not saying its gonna happen, but can't rule it out on a long range forecast.

[Steve]

Joe B has an early Saturday summary out. He has the CFSV2 which I only know where to find the weekly, monthly and seasonal forecasts. 3 of the 4 00z members hit Florida, one is farther east. One of the 3 is slow moving. Florida's definitely in the game, but recent runs seem a bit farther up. Not a model, but his track is north and east of the Bahamas which would be really good news for them if his track verifies. They'll have some scary moments next week though regardless.

[txwatcher91]

Nice to wake up to east shift, perhaps SE FL may be in the okay soon?

I wouldn’t count on that. Even if it stays offshore, the large wind field being modeled would likely bring TS force winds to coastal areas and increased waves too. This is forecast to be a fairly large storm as it reaches a tight pressure gradient due to the high pressure to the north.

[TheStormExpert]

Nice to wake up to east shift, perhaps SE FL may be in the okay soon?

I wouldn’t count on that. Even if it stays offshore, the large wind field being modeled would likely bring TS force winds to coastal areas and increased waves too. This is forecast to be a fairly large storm as it reaches a tight pressure gradient due to the high pressure to the north.

I'm guessing Irma will be a MUCH LARGER storm than Matthew once in or near the Bahamas region? Matthew came within 60 miles or so of West Palm Beach and still only produced strong-TS force winds at best.

[Bocadude85]

Nice to wake up to east shift, perhaps SE FL may be in the okay soon?

What east shifts? EURO shifted west and the GFS is similar to it's 0z run. Yes the ensembles shifted north but they seem to be bouncing around between Florida and the Carolinas.

[txwatcher91]

Nice to wake up to east shift, perhaps SE FL may be in the okay soon?

I wouldn’t count on that. Even if it stays offshore, the large wind field being modeled would likely bring TS force winds to coastal areas and increased waves too. This is forecast to be a fairly large storm as it reaches a tight pressure gradient due to the high pressure to the north.

I'm guessing Irma will be a MUCH LARGER storm than Matthew once in or near the Bahamas region? Matthew came within 60 miles or so of West Palm Beach and still only produced strong-TS force winds at best.

I’m not sure how much larger the actual size of Irma will be, maybe similar to Matthew. It seems though that if it’s a cat 5 and with strong HP all around Irma that the wind field will really expand, especially the N and NE sides of it that are closer to the strong HP. How close it gets to Florida is something to watch though since the Euro indicates some sustained TS winds along the coast of Florida due to the close approach.

[Spacecoast]

I wouldn’t count on that. Even if it stays offshore, the large wind field being modeled would likely bring TS force winds to coastal areas and increased waves too. This is forecast to be a fairly large storm as it reaches a tight pressure gradient due to the high pressure to the north.

I'm guessing Irma will be a MUCH LARGER storm than Matthew once in or near the Bahamas region? Matthew came within 60 miles or so of West Palm Beach and still only produced strong-TS force winds at best.

I’m not sure how much larger the actual size of Irma will be, maybe similar to Matthew. It seems though that if it’s a cat 5 and with strong HP all around Irma that the wind field will really expand, especially the N and NE sides of it that are closer to the strong HP. How close it gets to Florida is something to watch though since the Euro indicates some sustained TS winds along the coast of Florida due to the close approach.

It looks like more than TS winds to me, unless I am reading the chart wrong... It looks like >64 knot winds (even on the "good" side) around Cape Canaveral. Isn't that almost Hurricane force?

[DESTRUCTION5]

Last 3 Euro runs have trended dangerously close to Fl East Coast..I dont see much changing in the 12z like most are expecting because the Euro isnt nearly as bipolar at the GFS is. Im expecting something very similar to 0z give or take a few miles.

[Dean4Storms]

About the only thing you can reasonably remove from the likely track of Irma right now is a brush through the Antilles and toward the Keys. Everyone else from Florida up to New England is still reasonable under threat. Timing, Trough depth and movement and positioning of the Ridge over the Atlantic are all still quite likely to flip flop in the models beyond 4-5 days. Irma being still that far out any deviation can have large implications beyond 5 days.

Take Away? Folks need to stop with hanging on every run of the models beyond 4-5 days for now in thinking one way or the other so and so along the east coast is in the clear or the target! Breathe people!

[txwatcher91]

Looks like the hard wsw dive is beginning now. Eye is also starting to clear some too. Looks annular to me.

[xironman]

Joe B has an early Saturday summary out. He has the CFSV2 which I only know where to find the weekly, monthly and seasonal forecasts. 3 of the 4 00z members hit Florida, one is farther east. One of the 3 is slow moving. Florida's definitely in the game, but recent runs seem a bit farther up. Not a model, but his track is north and east of the Bahamas which would be really good news for them if his track verifies. They'll have some scary moments next week though regardless.

I doubt the authors of CFSV2 would intend for its usage in this fashion.

[txwatcher91]

FWIW, the 12z NAM agrees very well with the Euro position at hour 84 and is a bit south of the 06z GFS.

[cajungal]

Wonder if there was any way it could do a Betsy like loop.

[Mouton]

I’m not sure how much larger the actual size of Irma will be, maybe similar to Matthew. It seems though that if it’s a cat 5 and with strong HP all around Irma that the wind field will really expand, especially the N and NE sides of it that are closer to the strong HP. How close it gets to Florida is something to watch though since the Euro indicates some sustained TS winds along the coast of Florida due to the close approach.

The 65Kph wind field according to one model run I saw yesterday will extend almost 100+ miles to the west if this storm is a close to 900mb one as some models suggest. At that, it would be more destructive along the north east florida area than was Floyd even with a potential landfall above the Ga SC line.

[blp]

Just a reminder 91l (Pre-Harvey) Long Range models. Look at what the models did in the long range. A lot of things happened after that run. We cannot take these runs seriously yet past 7 days.

Pre Harvey GFS 00Z Aug 13: 


Pre-Harvey ECMWF 00Z Aug 13: