ATL: IRMA - Models

[AxaltaRacing24]

Stronger and more N

[stormreader]

We can begin (only just begin) to draw a few generalizations. No specifics... I think the chances of out to sea, without US impact, have dropped quite a bit. The deep trough is starting to look like a very transitional type feature---no lasting power. This could change, but both major models have shifted closer to the continental US, and the very steepness of the trough will actually encourage Irma (through the consequent strong Atlantic ridging to the east) to make an approach to the US coast (probably S Fl). Now what are the percentages that this steep early season trough remains in place for at least long enough to pull Irma north and out to sea.... Doubt it. The steepness and the time of year seem to argue for the trough being sort of gobbled back up by the ridge to the north of Irma. There could very well be enough of a temporary weakness to pull Irma up toward the Carolinas, definitely possible... but north of that, or out to sea, I think much less likely now. Now its also becoming a distinct possibility that the trough dissolves even quicker than anticipated, and Irma is pulled directly toward S Fl...or even more west than expected with renewed ridging, and carried along through the Fl Straits. Might sound unlikely now, but I wouldn't bet against it. Main thing is that out to sea is looking less likely IMO.

[meriland29]

Out of curiosity, and it may seem like a silly question but, when it comes to GFS, is there ever typically a rogue time (00z, 06z, etc) that is usually more correct than others, or vise versa?

[AxaltaRacing24]

Out of curiosity, and it may seem like a silly question but, when it comes to GFS, is there ever typically a rogue time (00z, 06z, etc) that is usually more correct than others, or vise versa?

The 18/00z runs are happy hour and late night party runs The 12z always seems tame though.

[RL3AO]

Out of curiosity, and it may seem like a silly question but, when it comes to GFS, is there ever typically a rogue time (00z, 06z, etc) that is usually more correct than others, or vise versa?

I don't have the stats, but the 18z runs have seemed off compared to other times.

[RL3AO]

Maybe 25 miles north of the 12z run. Same speed.

[Steve H.]

I used to hear that 06z and 18z were the "off" times for the models, but that may be only when they are getting recon data from a storm. It could just be an urban myth though.

[meriland29]

Maybe 25 miles north of the 12z run. Same speed.

That is so weird. Definite windshield wiper effect, this one is N of 12z, and 12z was S of 06z..

[weathaguyry]

Out of curiosity, and it may seem like a silly question but, when it comes to GFS, is there ever typically a rogue time (00z, 06z, etc) that is usually more correct than others, or vise versa?

The 18/00z runs are happy hour and late night party runs The 12z always seems tame though.

If a hurricane into Rhode Island came from the "tame" 12z, then what will it show on the 18z happy hour run!?

[AxaltaRacing24]

Shifted south compared to earlier which puts it on top of the 18z

[RL3AO]

I used to hear that 06z and 18z were the "off" times for the models, but that may be only when they are getting recon data from a storm. It could just be an urban myth though.

That probably goes back to the days when the models relied more on the weather balloons at 0 and 12z. Now, >99% of the data that goes into models comes from satellites, airplanes, and other non-balloon sources.

[RL3AO]

Moving due west at 16N. Still a little bit north of 12z, but otherwise the same.

[BYG Jacob]

Out of curiosity, and it may seem like a silly question but, when it comes to GFS, is there ever typically a rogue time (00z, 06z, etc) that is usually more correct than others, or vise versa?

The 18/00z runs are happy hour and late night party runs The 12z always seems tame though.

If a hurricane into Rhode Island came from the "tame" 12z, then what will it show on the 18z happy hour run!?

Category 5 into Canada coming right up!

[meriland29]

Looking at the 12z vs 18z for the same timeframe, looks almost identical. Just a hair (I do mean a hair) N of 12z, and a tad slower.

[Blown Away]

18z GFS... @78 hrs gets down to @16.1N, the NHC's lowest point is 16.4N...

[Steve H.]

I used to hear that 06z and 18z were the "off" times for the models, but that may be only when they are getting recon data from a storm. It could just be an urban myth though.

That probably goes back to the days when the models relied more on the weather balloons at 0 and 12z. Now, >99% of the data that goes into models comes from satellites, airplanes, and other non-balloon sources.

So true. Thanks for pointing that out!-

[ConvergenceZone]

We will see if we get another Upper East Coast landfall on this run

[meriland29]

hr84-90, W to NW turn

[AxaltaRacing24]

[Blown Away]

18z GFS... 96 hours... @17N/55.1W... NHC 96 hour position is 17N/56.5W