ATL: IRMA - Models

[RL3AO]

[SouthFLTropics]

One thing is for sure, there are definitive differences between the GFS and the Euro beyond day 5-6. Looks like we've got an old school Euro vs. GFS battle. Let's find out how good this new GFS is.

[Michele B]

It should recurve?

That actually looks like a stall in the Bahamas

Isn't that what Matthew did to them?

Then scraped all the way up the Eastern Seaboard?

[Bocadude85]

It should recurve?

Not if that ridge starts building in as the trough pulls out. It could just stall and then continue west as a ridge builds in. The NAO is forecast to be positive which should favor ridging on the east coast. Seems like a very complex pattern setting up and we may not know how much of a threat Irma will be to the USA for probably another week or so.

[KWT]

Motion from 234 to 240hrs is near NW. Could well be a coastal racker, broadly similar to hurricane Irene woul be my early guess if the 12z ECM carried on.

Anyway, down to 933mbs by 240hrs ad smashing the Bahamas, heading NW.

[sma10]

Really hope the stall doesn't actually materialize 5 degrees further west. A major landfalling hurricane stalling and affecting a metropolitan area? What are the odds of that happening ... again?

[Hurricane Andrew]

Motion from 234 to 240hrs is near NW. Could well be a coastal racker, broadly similar to hurricane Irene woul be my early guess if the 12z ECM carried on.

Anyway, down to 933mbs by 240hrs ad smashing the Bahamas, heading NW.

NO

Please, no.

[BensonTCwatcher]

The key here is that ULL and how strong it is from h48 to h120 - That's sort of like "stage 1" which will set up the position, strength and orientation of the ridge. If it retrogrades quickly a la ECMWF then we have trouble. If the ULL follows more of the GFS solution- and ULL retrogrades slowly, then we are in luck with the NE-SW tilt to the ridge and possible weakness. Whichever way that turns out, "Stage 2" is the trough and how deep it digs and/or interacts with whatever is showing up in the gulf. If it connects the trough may be deep enough to pick this up, or the gulf low gets cut off (or never really pans out) and the trough remains more zonal at h240+ we're back in trouble again.

Going to be storm to watch this Irma.

[Blinhart]

Verbatim, there is no turn from hour 234 to 240.

Looks like it is trying to interact with the GOM system.

Um... that's catastrophic.

What a cliffhanger.... It either heads to the GOM and interacts with Jose, lifts out, or devastates Florida.

That wouldn't be Jose, Jose would already be gone, that would be the next one.

[DESTRUCTION5]

Really hope the stall doesn't actually materialize 5 degrees further west. A major landfalling hurricane stalling and affecting a metropolitan area? What are the odds of that happening ... again?

Ask 2004-5

[fox13weather]

240 hour forecasts are what they are. 240 hour forecasts. I have lost count of the number of "WE WILL HAVE TO WATCH THIS ONE" "IF I WAS ON THE EAST COAST I'D BE MAKING PLANS" I've seen posted here only to have nothing materialize. Yes, sooner or later one of these 240 hour forecasts will be somewhat useful, but the track record speaks for itself. Just think, maybe the GFS will be correct and the storm will get picked up the by the big east coast trough? Could happen. It's a marathon. Not a sprint.

[ConvergenceZone]

Hopefully someone will post the model run going further out.

[SFLcane]

I see..

[ConvergenceZone]

Shouldn't the model run extend until Sep 13th? Or is that only the GFS? Because I saw that yesterday

[wxmann_91]

240 hour forecasts are what they are. 240 hour forecasts. I have lost count of the number of "WE WILL HAVE TO WATCH THIS ONE" "IF I WAS ON THE EAST COAST I'D BE MAKING PLANS" I've seen posted here only to have nothing materialize. Yes, sooner or later one of these 240 hour forecasts will be somewhat useful, but the track record speaks for itself. Just think, maybe the GFS will be correct and the storm will get picked up the by the big east coast trough? Could happen. It's a marathon. Not a sprint.

This. ULL's are usually a little more tenacious than progs initially suggest and Euro has a south bias. All the options are still on table. Including a quick OTS.

[txwatcher91]

The key here is that ULL and how strong it is from h48 to h120 - That's sort of like "stage 1" which will set up the position, strength and orientation of the ridge. If it retrogrades quickly a la ECMWF then we have trouble. If the ULL follows more of the GFS solution- and ULL retrogrades slowly, then we are in luck with the NE-SW tilt to the ridge and possible weakness. Whichever way that turns out, "Stage 2" is the trough and how deep it digs and/or interacts with whatever is showing up in the gulf. If it connects the trough may be deep enough to pick this up, or the gulf low gets cut off (or never really pans out) and the trough remains more zonal at h240+ we're back in trouble again.

Going to be storm to watch this Irma.

So far this season the Euro has proven to be superior to the GFS with both TC development and ULL track. GFS does pretty well with intensity once a storm forms but a Euro/UK combo on track inside 5 days with a heading for the islands is very concerning.

[hohnywx]

Hopefully someone will post the model run going further out.

The Euro doesn't go further out...

[KWT]

I see..

Outstanding image there, gives a neat idea of just how impressive this hurricane becomes on the 12z ECM.

We do at least have very good agreement at last that this will be a major hurricane at some point, and probably a very large ACE maker (if it takes the southern route, probably looking at 40-60, the northern and somewhere between 30-50)

[OuterBanker]

Wow, really haven't seen a tropical system this well formed this far east in quite some time.
Potential to be a real monster in which no one wants to see.
Almost always a fish this strong this far east and north, but the projected path and building high do have me concerned.
Amazing that we have thirty-seven pages of models for a storm that is at 31 w.
Lots of Xanax scripts filled in the next two weeks.
With any luck though it will simply up the ACE and harm no one.

[Mouton]

The true face of the ridge has not revealed itself yet. More than 10 days out it is a crap shoot. The latest Euro seems a bit farther north then the earlier one at day 5 but again, we don't know what the ridge will be doing at that time. If it builds back into the projected 1020 high coming from the west, Irma could definitely get trapped asea, just turning not unlike Harvey near Houston. HARF models pumps this up to a cat 5 902mb by day 10. IOW, this would be the equal of a Floyd in diameter. Perhaps it gets knocked down a tad it if bumps into Hispanola but I think it will go north of it. To me it does not have a GOM tag on it unless it were to run up the west side of Florida. Hopefully a close call EC rider but given its power, even if it is 100 miles from the coast, it will have big impacts on the weaker side.