ATL: IRMA - Models

[tgenius]

After seeing Katrina skirt SW at the last minute unexpected (yes I understand that it's a different setup) if it's 100 miles off coast at 7 days that's concerning a bit.

[SFLcane]

Was indeed another westward shift by the GFS.

[ronjon]

Looks like Moorehead City NC landfall on GFS.

[northjaxpro]

As we have discussed earlier today, the very disturbing SW shift continues in the 18Z GFS run. This is not good at all!

Northjax,
I value your opinion especially being located in St Augustine. At what point this week should we look at evacuation plans, preparations, etc?

Thank you to all of you for valuable information.

Hey Tigerz3030. It has been awhile since we chatted. Right to the point here. It is all going to hinge on the timing and sppeed of the trough and ridge placement which is going to dictate the steering of Irma this up coming week. Tigerz, I am strongly urging you to do whatever necessary preparations to prepare for this potential impact from Irma NOW!!! The models are now showing that Irma COULD potentially impact the entire East Coast of Florida later this week into next weekend. Time is very precious now!! You do not want to be in a situation in which you will not be able to finish all necessary things you need to do to prepare against this storm.

So, pay very close attention to the NHC , John Gaughn, who I respect the most locally here on Jax TV-4, and of course all of us here on Storm 2K for the latest developments. I have a feeling we are in for one heck of a week!

[Hypercane_Kyle]

So the GFS and Euro are bringing Irma within 100 miles of S.Fla in 7 days...I have been saying for days that I'd rather see a landfall here in the long range because it most likely won't happen...the models refuse to bring Irma into Florida, instead they just keep shifting southwest and getting closer and closer..not a good trend.

Yea, the trend alone should be enough to keep Florida on its toes. Models look pretty confident in the NW turn at some point, but I'm worried that the hurricane makes it to Florida when that turn happens...

[ROCK]

https://www.tropicaltidbits.com/analysis/models/?model=gfs&region=atl&pkg=z500trend&runtime=2017090318&fh=168&xpos=0&ypos=300

Look at the timing. Faster, Irma gets a shot out. Any slower, it's going to be blocked for 3 days or so because it's not getting through the high.

Linear Forecast Trend 48 Hours - Critical to view for the synoptics!
https://www.tropicaltidbits.com/analysi ... 0&ypos=300

Basically a race to the coast. Timing is unfortunately is so important in these cases. Might not have an idea until 3 days out to react. Not wanting to be in Soflo later this week with the current Euro ensembles..jmo

[Aric Dunn]

im not buying this run or the euro.. as they both have this very strange low pressure that develops over the mississippi valley in the mid and upper level that stops the ridge from building back in and drive it north. otherwise without that trough since it lifted out there is nothing to move it.. unless ridging builds in behind the trough but it doe snot becasue of that very strange low..


they both were doing that two days ago with a very odd mid to upper low that they both developed over virginia driving it north into new england..

looks like another transient feature.

also notice hte nw turn after landfall. its interacting with that weird low..

[stormreader]

Landfall Imminent in Southern NC at 192.

That's the Cape Fear NC area that I mentioned in my "Irma window" forecast for my own personal landfall prediction. When I made that call a couple of days ago I put Cape Fear at my furthest north landfall point. I still think that, but think odds are greater for a landfall further south.

[Sciencerocks]

Landfall on the 18z gfs is North Carolina at 887mb. There's never been one anywhere close to that to hit North Carolina and I doubt the TCHP would even support such.

I don't buy the stall in at 174-180 time period either...This thing is most likely going to have about the same set-up as Frances.

[Kingarabian]

18zGFS 879mb...

[CrazyC83]

Landfall on the 18z gfs is North Carolina at 887mb. There's never been one anywhere close to that to hit North Carolina and I doubt the TCHP would even support such.

I don't buy the stall in at 174-180 time period either...This thing is most likely going to have about the same set-up as Frances.

Lowest known pressure in that region is 930mb (Helene 1958).

[Hypercane_Kyle]

Yea, the GFS intensity forecast is clearly bonkers... does that all the time in the WPAC.

[plasticup]

Landfall on the 18z gfs is North Carolina at 887mb. There's never been one anywhere close to that to hit North Carolina and I doubt the TCHP would even support such.

It actually gets down to 879 mb in that run. That's insane. More than 50 mb deeper than the next most intense NC hurricane ever. Very unlikely.

[Kingarabian]

18z GFS 192 -> 222

[sma10]

Lets not kid ourselves - the models are just not good enough at D7 to predict a turn so precise at 79W, that it defies credulity that they both have it perfect right now. A turn? Sure i can buy that - but the question is where does it actually occur? Further east or further west? Or do the models have it perfect right now?

What do you think?

[tolakram]

GFS continues to over-strengthen storms. Not sure if this is effecting the track or not.

[rockyman]

Question for the group. Since "the turn" isn't forecast for 6 days, is there anything we should be watching in the models for the next couple of days, to determine if the turn might happen later than currently forecast? I'm asking this as a Northern Gulf Coaster. Thanks for any responses.

[CrazyC83]

I do wonder if the pressures are overestimated as well. There has NEVER been a sub-900 pressure in the open Atlantic - all of them were in the western Caribbean, the Gulf of Mexico or the Florida Straits. Plus wouldn't that storm just go through ERC's?

The lowest pressures I know of in the open Atlantic are 915mb from Isabel (estimated) and 918mb from Hugo (measured).

[p1nheadlarry]

GFS just created frankenstein.

[Steve]

I don't know Aric, I disagree a little. I think the second push of the trough which is the one lifting out 6-7 days is followed by the high behind it. If you run the linear forecast trend at TT, you see the green outlines which represent 99% confidence. You will also see the high building in over the top from the west at 204 hours. That should be enough of a push for this to continue due north, slow and then figure out whether it comes up north, northwest or finds its way out to sea.
https://www.tropicaltidbits.com/analysi ... 318&fh=216