ATL: IRMA - Models

[SouthFLTropics]

HWRF 117 hour TREND

[sma10]

My trig is a little rusty, but it looks like HWRF and GFS are separated at the 120hr mark by ... maybe 200 miles?

[Frank P]

Looking bad for the Bahamas

[Steve]

You have momentum issues with the HWRF to contend with as well. 117 Hours it's been a Cat 4 for probably 4 days at that point. You'd think an ERC would take place though it halfway looks annular in the depiction.

@ 117 hours, it's at 20.2N 68.2@ and 926mb. Scary and just north of the DR.

[Alyono]

HWRF bring hurricane conditions to Antigua, but a LANDFALL on Anguilla as a category 5 hurricane. Looks like cat 3 winds on St. Martin

[stormreader]

Be careful with the NAVGEM verification speaking it is not the sharpest model in the shed....The EURO runs are bad for someone in FL and the EC....way to far out to pinpoint are even make an educated guess attm. What we do know is this is not coming into the GOM which is a good thing.

IDK Rock. Lets put it this way, I think the percentages for Irma being in the GOM are higher than for the Outer Banks and points further north. Consider, even affects the central Fl coast, there is still a reasonable chance that she will enter the NE GOM. Other scenarios too. Still a long way to go. I can't yet say that it is written in stone that the trough will have the depth and staying power to keep Irma out of the GOM. Yes, a Carolina landfall would do that, but other locations further south or not out of the woods, and that would bring at least a part of the GOM in play. Heck, I still have S Fl and the Fl straits in play, but I know I must be in a very small minority to consider a trek that far south. That would basically suppose that Irma misses the trough altogether. I'm not ruling that out, at this point. I am ruling out the out to sea path. IMO

[SouthFLTropics]

looks like it turned back west almost .. getting very close to DR

Aric, at what distance would a storm of Irma's magnitude have to get from the mountains of PR and Hispaniola for them to have an influence on its track? I'm not sure of the physics involved or frictional surface forces but I would think that if it got close enough that could be a factor to pull it South. We've seen it before with Ivan jogging around Jamaica.

[Aric Dunn]

All in all a big shift south for the HWRF

[Steve]

144H NAVGEM is going to have to hook immediately to catch the trough pulling out. If not, FL/GA/SC?
https://www.tropicaltidbits.com/analysi ... 218&fh=144

[Aric Dunn]

looks like it turned back west almost .. getting very close to DR

Aric, at what distance would a storm of Irma's magnitude have to get from the mountains of PR and Hispaniola for them to have an influence on its track? I'm not sure of the physics involved or frictional surface forces but I would think that if it got close enough that could be a factor to pull it South. We've seen it before with Ivan jogging around Jamaica.

honestly its not well understood. and but the eyewall would probably have to get pretty close.. it all depends on anlge of approach too.

[Nimbus]

You have momentum issues with the HWRF to contend with as well. 117 Hours it's been a Cat 4 for probably 4 days at that point. You'd think an ERC would take place though it halfway looks annular in the depiction.

@ 117 hours, it's at 20.2N 68.2@ and 926mb. Scary and just north of the DR.

If they were not preparing for mud slides in the mountains of Hispaniola they should be now.

[SFLcane]

Significant shift S on the HWRF bringing the islands and PR in play.

[Bocadude85]

HWRF bring hurricane conditions to Antigua, but a LANDFALL on Anguilla as a category 5 hurricane. Looks like cat 3 winds on St. Martin

The northern BVI also take a direct hit.

[Bocadude85]

If the 18Z HWRF where to go out beyond 126 hours it looks like the Turks & Caicos would take a direct hit.

[ronjon]

This is speculation on my part but is the HWRF actually showing how a very strong storm can pump up the ridge?

[txwatcher91]

I don't buy the significant south shift on the HWRF at all. It struggled with Harvey and continually took it into Mexico or extreme southern Texas, turned it west and dissipated it in the mountains. It wasn't even remotely close and has seemed to be on the south side of guidance this season. Now if the Euro and GFS start coming in south like the HWRF, then I'll start to believe it.

[SFLcane]

[Blinhart]

And look at Jose right behind Irma as what a Cat 3?

[sma10]

Perhaps the HWRF run is the realization of those southern ensemble members of GFS?

[Nimbus]

This is speculation on my part but is the HWRF actually showing how a very strong storm can pump up the ridge?

Could be a "what if" run with parameters that give a more southern solution.
If all the models are south in 12 hours than we will know the actual environment variables are trending that way.

The forecast turn back to the WNW is still when Irma is ~ 48 hours from the islands.