ATL: IRMA - Models

[NFLnut]

NAM had the jump on Katrina 3 days out... 1st to suggest landfall west of Florida panhandle. If my memory serves me right.

Blind squirrels occasionally find nuts.

[PTPatrick]

WEll I think if there were any hold outs it should be pretty apparent Miami Metro has some major problems on its hands. I think we are close enough to landfall huge swings are not likely. Sure it may still be a hair offshore. but the models are coalescing around a landfall between Fort lauderdale and Marathon Key. A few wobbles here and there will certainly make a huge difference for wind effects. I think the best folks can hope is a track that keeps the eastern eyewall offshore at this point. Even the west shifts into the everglades may not spare the more populated areas high surge and wind. So now we have GFS basically crossing cities with the eye(but not the eyewall since I gather it will be a big eye), Euro right through the cities, CMC thru Key largo with the eyewall likely scraping the cities, and the UK Met over Marathon through the everglades. That's not the kind of convergence you want to keep the urban corridor on the cleaner side.

Keys going forward are what happens with strength, and size, and angle of approach as this is a worst case surge scenario for miami. Most of these factors will be very hard to tell until 24-36 hrs before landfall. It appears it will be on the upswing strengthwise as it lands, but as everybody knows strength is hardest to predict. If I lived anywhere down there I would be prepared for cat 5 devastation and hope for cat 2 inconvenience.

[miamijaaz]

HWRF landfall in Miami-Dade County at 72 hrs. Significant west shift. I think that's the first landfall the HRWF has shown in Miami-Dade for at least a couple of days.

Edit: Run looks strikingly similar to NHC forecast.

[ronjon]

12z GFS ensemble mean - now west - well inland.

https://www.tropicaltidbits.com/analysis/models/?model=gfs-ens&region=us&pkg=mslpa&runtime=2017090712&fh=24&xpos=0&ypos=0

[sponger]

HWRF very close to landfall in SE FL at 66 hours and southwest of the last run that kept it offshore at 06Z.

https://www.tropicaltidbits.com/analysi ... 0712&fh=66

HMON about to 2nd landfall just across the FL/GA Border at 90 hours
https://www.tropicaltidbits.com/analysi ... 0&ypos=284

883 mb at landfall, an absolute disaster.

[miamijaaz]

HWRF still heading NNW at 78hrs. That's a first.

[Voltron]

Never know may still be hope for east. Hang in guys

[facemane]

yuck..no way. Fortunately its related to the NAM I can only recall on one hand how times that thing panned out in the last 10 years

NAM had the jump on Katrina 3 days out... 1st to suggest landfall west of Florida panhandle. If my memory serves me right.

Interesting. I vaguely remember a single model being an outlier but this was a long time ago. All model I remember had it curving between Pensacola and Tampa after the straights but the cone kept shifting.[/quote]

it was the UKMET that had Katrina landfall near the mouth of the Ms. first.

[stormreader]

HWRF landfall in Miami-Dade County at 72 hrs. Significant west shift. I think that's the first landfall the HRWF has shown in Miami-Dade for at least a couple of days.

Edit: Run looks strikingly similar to NHC forecast.

Don't look for big changes now. And if anything the minor shifts will be west IMO.

[CaptinCrunch]

@ 3 days out I said Harvey would make landfall between Corpus and Matagorda Bay. @ 3 days out Irma will be Miami's worst nightmare with a full eye landfall between Key West and Miami, the question is how far inland will it travel before making its way back off the Eastern coast of Florida before effecting the Carolina's.

[Steve]

Never know may still be hope for east. Hang in guys

I'm waiting for the ECMWF to say "it" but I think the east of Florida runs are almost over. HMON/HWRF/CMC have all come around to a SFL/SEFL landfall. GFS is behind the curve and has been for most of Irma's history with a bias east and north. HWRF has been biased East as have recent HMON runs which are correcting. We're awfully close to having the models essentially confirm the NHC's track of a Category 4 or 5 into S FL early Sunday morning. There's the possibility of a second landfall still or a ride up FL into the SEUS. That all still remains to be seen. I'm not trying to be a harbinger of doom here, but this is shaping up to be a $50-60B storm for the United States, possibly higher, and one of the worst on record for SEFL due to all the construction that has occurred since 1992.

[Steve]

HWRF very close to landfall in SE FL at 66 hours and southwest of the last run that kept it offshore at 06Z.

https://www.tropicaltidbits.com/analysi ... 0712&fh=66

HMON about to 2nd landfall just across the FL/GA Border at 90 hours
https://www.tropicaltidbits.com/analysi ... 0&ypos=284

883 mb at landfall, an absolute disaster.

Fortunately that's not going to happen. Someone said they had to clamp it down on intensity because it has runaway pressures. I'm not really that familiar with it as I think this is only the first or second year since it replaced the GFDL.

[wxman57]

Brian Tang, a member of the tstorms email group, posted a graphic out of the Univ. of Albany comparing model errors with Irma. Euro has beaten the other models by a long shot. As expected, NGP/NOGAPS is bringing up the rear. HMON has been pretty bad. HWRF is middle of the pack. GFS - not so good. Interesting that the 00Z Euro predicts a pressure drop from 938 to 921mb as Irma is turning north toward Florida.

1. ECMWF
2. UKMET
3. NHC
4. Canadian
5. HWRF
6. TVCN
7. GFS
8. HMON
9. CTCX
10. NGX/NOGAPS
11. COTC

[djones65]

Based upon the graphic US Tropics posted regarding verification of model performance with Irma thus far:

The ECMF has been very best overall by far! Interestingly, the UKMET has been 2nd best with both outperforming the official NHC forecasts thus far. And surprisingly the Canadian CMC model is close 3rd thus far, and within 72 hours forecast points the CMC is performing second best. The GFS model has performed extremely poorly and has been the 3rd WORST so far.

Thanks US Tropics for this graphic!

[gatorcane]

[NFLnut]

.. and one of the worst on record for SEFL due to all the construction that has occurred since 1992.

Yes. But building codes were MAJOR upped after Andrew, especially in SE Florida. Unfortunately, I think we will be putting those revised codes to the test.

[CaptinCrunch]

Good grafic but about 50 miles to far east

[gatorcane]

Slight west shift with GFS ensembles mean:

[miamijaaz]

Never know may still be hope for east. Hang in guys

I'm waiting for the ECMWF to say "it" but I think the east of Florida runs are almost over. HMON/HWRF/CMC have all come around to a SFL/SEFL landfall. GFS is behind the curve and has been for most of Irma's history with a bias east and north. HWRF has been biased East as have recent HMON runs which are correcting. We're awfully close to having the models essentially confirm the track of a Category 4 or 5 into S FL early Sunday morning. There's the possibility of a second landfall still or a ride up FL into the SEUS. That all still remains to be seen. I'm not trying to be a harbinger of doom here, but this is shaping up to be a $50-60B storm, possibly higher, and one of the worst on record for SEFL due to all the construction that has occurred since 1992.

If it turns out that an east track offshore is not going to happen, perhaps the "best" option is for the track to keep shifting west and come up the spine: through the middle keys north, through the everglades, past the Broward/Collier county line, through Lake Okeechobee and out to shore. It will be bad for the keys and both coasts, but it would spare the most highly populated areas of Miami/Broward/WPB and Naples/Ft.Myers from the eye wall of landfalling Cat 4-5.

[Vdogg]

Hello Everyone-

I am going to ask the same question that I asked about the UKM model , does the NAVGEM have any validity

Craig

Below is how the models have performed so far with IRMA in relation to positional error (note the NGX is the NAVGEM and has not performed particularly well):


Model bias at 72, 96, and 120 hours:

Where is the GFS on these charts?