ATL: IRMA - Models

[La Sirena]

UKMET pretty much locked in on a SE FL hit, up through the spine or a couple of miles east of it.

This run knocks out Metro Dade and Broward.

Don't forget the Keys, too.

[ronjon]

Ronjon-

How serious do we take the UKM model and that track if verified would change impacts on the west coast is that correct?

Well UKMET has shown some stellar preformance in the past - it did well with Matthew last year and think it did well with Harvey. if there is one bias of UKMET, its been that it sometimes shows a little stronger ridging than other models. Often times it aligns well with the ECM so its highly regarded in that sense. I'd advise not putting all the eggs in one model basket - look for trends. So far with today's guidance that trend is slightly west. Impacts obviously go up with a more down the spine of the state path with Tampa - still on the west side of the storm but certainty higher winds and more rain if that track verified.

[Frank P]

The NHC has their storm-surge maps up for Irma in the graphics section.

Direct link to the model's inundation map:

http://www.nhc.noaa.gov/refresh/graphic ... n#contents

I looked at that map and unless I am reading it wrong I don't see any surges 3 feet and greater north of South Miami... which means the highest expected from the areas north of South Miami up the coast through Sunday 5 pm could be up to, but not exceeding 6 feet.. I'm assuming 6 feet is a lot of surge for the greater Miami area.. I was thinking it might be possible up to the 9 foot range .. not that familiar with the potential surge affects on the SE coast of FL at this level, South Miami and areas south, levels were classified at up to 9 feet and greater as the max..... 6 feet with significant wave action would still do tremendous damage however for all the low lying structures, and I'm assuming there are a plethora of them... SW FL coastal areas show up to 9 feet and greater and that includes parts of Everglades city Chokoloskee, the area below is the Everglades...

[Steve]

HWRF is coming in slightly SW of its 06z run.

6 Hours
06Z - 21.15N 69.9W @ 907mb
12Z - 20.95N 70.2W @ 916mb

Not all that much, but the 06Z run was an eastern outlier.

15 Hours
06Z - 22.1N 71.85W @ 914mb
12Z - 21.8N 72.25W @ 919mb

[txwatcher91]

It seems like models are converging on Miami and surrounding areas as ground zero for the eye of Irma. Even worse, the EWRC will be done well before then and this could be near peak intensity. This is looking VERY bad for South Florida. I imagine the angle of approach from the south would also drive a good bit of surge into the area.

[Steve]

I don't care about the "sudden" consistency of the gfs, I'll put my eggs in ukm basket

I'm not sure it's right though. It's the only model (or one of the only major models) to still insist that it goes over Cuba, and not just a brush-by either. Once in a while it is right when it is an outlier (reference Ivan 2004, Matthew 2016). I'm not sure this time. If I only had one model basket, it would be the ECMWF which has even outperformed the NHC so far with Irma.

UKMET is also showing a Cuba landfall.

Yeah. that's what I was saying. Euro did not.

[SEASON_CANCELED]

Well Gentlemen..place your bets

UK MET/NAM up SW...Euro up the middle.. all others to the South east


regarding GFS and Intensity. Well...we see phantom storms with ridiculously low pressures modelcasted all the time. This is one it got correct for once. GFS has been accurate in predicting this as a monster for awhile now..its track is not as good as euro.

[HURRICANELONNY]

I am hoping that that short wave seen on loop pulls Irma east of Florida and defies the models.

http://www.ssd.noaa.gov/goes/east/eaus/flash-wv.html

[tolakram]

 https://twitter.com/pppapin/status/905821713467936768




Philippe Papin @pppapin
Maps via Brian Tang's @UAlbanyDAES show #GFS has had a consistent poleward bias with #Irma. The #ECMWF in contrast has been spot on.
11:55 AM - Sep 7, 2017 · New York, USA

[otowntiger]

Do you think the NHC cone at 5 will shift West because of these runs or stay the same?

I''m pretty sure at this point the NHC track essentially locked. You'll see very little shifts, except for slight 'nudges' one way or the other, much like they did at 11:00. Regarding the models at this point they could very well shift or more accurately 'nudge' one way or the other. I expect more nudging back east again. just my amateur opinion fwiw =2 cents.

[HURRICANELONNY]

I'm rooting for the GFS. Go GFS stay east. I always called the GFS Get Florida Soon. Maybe I should want the model showing it hitting me. I know I'm going to get tropical/hurricane force winds. I just don't want the eye by me.

[Steve]

HWRF 33 Hours:

06Z - 23.3N 75.5W
12Z - 23.0N 75.9W

Southwest still.

[tolakram]

 https://twitter.com/RyanMaue/status/905829009216430080



Ryan Maue ✔ @RyanMaue
Most recent GFS model traces well @NHC_Atlantic forecast track. Huge Hurricane #Irma effects dependent upon only 25-50 miles deviation
12:23 PM - Sep 7, 2017

[hcane27]

In checking the last available forecasts it appears as though Irma is currently south of major models GFS , ECMWF , and right on target for UKMET.

[NDG]

https://twitter.com/pppapin/status/905821713467936768

Philippe Papin @pppapin
Maps via Brian Tang's @UAlbanyDAES show #GFS has had a consistent poleward bias with #Irma. The #ECMWF in contrast has been spot on.
11:55 AM - Sep 7, 2017 · New York, USA

https://i.imgur.com/IvUFCc4.png

I was about to mention on how right biased the GFS has been even on its short term range.

[Steve]

HMON nicked Biscayne Bay & Miami at 06Z and was close but probably a hair too far east.

57 Hours

06Z - 24.3N 79.7W
12Z - 24.0N 79.5W

Slightly SE of prior run so a bit slower.
https://www.tropicaltidbits.com/analysi ... 0712&fh=57

[gatorcane]

12Z NAVGEM way west:

[USTropics]

The NHC has their storm-surge maps up for Irma in the graphics section.

Direct link to the model's inundation map:

http://www.nhc.noaa.gov/refresh/graphic ... n#contents

I looked at that map and unless I am reading it wrong I don't see any surges 3 feet and greater north of South Miami... which means the highest expected from the areas north of South Miami up the coast through Sunday 5 pm could be up to, but not exceeding 6 feet.. I'm assuming 6 feet is a lot of surge for the greater Miami area.. I was thinking it might be possible up to the 9 foot range .. not that familiar with the potential surge affects on the SE coast of FL at this level, South Miami and areas south, levels were classified at up to 9 feet and greater as the max..... 6 feet with significant wave action would still do tremendous damage however for all the low lying structures, and I'm assuming there are a plethora of them... SW FL coastal areas show up to 9 feet and greater and that includes parts of Everglades city Chokoloskee, the area below is the Everglades...

I would also advise looking at previous systems that have heavily hit this area - my top three would be 1926 Miami hurricane, Andrew, and Cleo (Irma will most likely be stronger).

At 105mph, Cleo's storm surge reached 4–6 feet (1.2 m–1.8 m) between Miami and Pompano Beach.

For the 1926 Miami Hurricane, along Biscayne Bay, the hurricane produced a substantial storm surge; visual estimates suggested a peak height of 14–15 ft (4.3–4.6 m) in Coconut Grove, and a value of 13.2 feet (4.0 m) occurred at Dinner Key, though the value was somewhat lower at 11.7 feet (3.6 m) along Biscayne Boulevard in Downtown Miami. In fact, the storm surge measured in the 1926 hurricane was the highest ever officially documented on the east coast of South Florida until observers recorded a height of 16.89 ft (5.1 m) at the Burger King International Headquarters near Cutler in Dade County during Hurricane Andrew in 1992. Also in the 1926 Miami Hurricane, The hurricane's high storm surge swept into Miami and Miami Beach, flooding city streets with knee-deep water. Yachts and large vessels were carried by the intense wind and waves onto shore.

Also Lake Okeechobee has a history of storm surge threats as well, including from the 1926 Miami Hurricane:

"A storm surge from Lake Okeechobee entirely inundated Clewiston, reportedly leaving numerous bodies along the road connecting the city with Miami. Further inland, the surge burst through frail, earthen, 6-foot (1.8 m) tall muck dikes, submerging Moore Haven under 13–15 ft (4.0–4.6 m) of water. Residents scrambled, often unsuccessfully, to safety on rooftops but were swept away by the winds and storm surge. A nearby drainage dam was destroyed, causing additional flooding of the countryside. Most of the city's buildings were swept off of their original foundations.Reports by the Red Cross and local authorities indicated that 150 human corpses were found in Moore Haven alone; their estimates were incomplete as many bodies were never found, reportedly having been swept deep into the Everglades. Estimates of the dead near Lake Okeechobee ranged as high as 300. Two years later, another Category 4 hurricane killed at least 2,500 people along Lake Okeechobee, but mostly affected the eastern shore, leaving Moore Haven largely unscathed."

It's true that the deep offshore continental shelf reduces storm surge near SE Florida compared to other parts of our state, but it still can be quite serious.

[Hurricane Andrew]

Wouldn't the astronomical OHC/SST values in the Straights counteract any land interacting with Cuba?

[SEASON_CANCELED]

12Z NAVGEM way west:

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