ATL: IRMA - Models

[MrJames]

From the 5AM discussion:

The timing of the turn is the most important question and one still filled with
uncertainty. The UKMET, UK Ensemble mean, and the NAVGEM are the
models showing the latest turn, and they forecast Irma to move into
the southeastern Gulf of Mexico and near the west coast of the
Florida Peninsula. The ECMWF and ECMWF Ensemble mean are in the
middle of the model pack and show Irma moving over the southeastern
portion of the Florida Peninsula. The GFS, Canadian, and GFS
Ensemble mean show the earliest turn and show Irma moving east of
the coast of Florida toward the southeastern United States. The
new forecast track will best follow the ECMWF, as well as the
Florida State Superensemble and the HFIP Corrected Consensus, and
it calls for the center to move over portions of the southeastern
Florida Peninsula between 72-96 h and then across the Atlantic into
southern South Carolina by 120 h. Users are again reminded not to
focus on the exact track since the average NHC track errors at days
3, 4, and 5 are about 120, 175, and 225 miles, respectively.

UKMet ensembles

[Alyono]

6Z GFS about 30 miles closer to Florida

[stormreader]

0z Euro is if anything a slight shift to the left at least in the track across northern coastal FL.
Not good that the Euro is getting this consistent, which means a significant shift of the track by the Euro is not looking likely.
SE FL is now within 72 hrs of a possible direct impact by Irma, with a worst case trajectory for almost the whole entire FL eastern coast.

Edit: After I looked back the latest 0z Euro run actually shifted the track of Irma approximately 20 miles to the west from the previous 12z run on the track across S FL, this is 2 runs in a row that it has shifted a little to the west.

Yes. Looks like a big hit. After flirting with further east for a run, I think this is three in a row by the Euro on shore in S Fl. Just about at the confirmation time now for what's about to happen. The consistency is there now (Euro runs in general have been more consistent in the last three days or so). Watch for 12z as that is fully within the 72 hr window. But I think any minor shifts will probably trend just a tad west. You can see the more significant west trends further north in the run.

[stormreader]

From the 5AM discussion:

The timing of the turn is the most important question and one still filled with
uncertainty. The UKMET, UK Ensemble mean, and the NAVGEM are the
models showing the latest turn, and they forecast Irma to move into
the southeastern Gulf of Mexico and near the west coast of the
Florida Peninsula. The ECMWF and ECMWF Ensemble mean are in the
middle of the model pack and show Irma moving over the southeastern
portion of the Florida Peninsula. The GFS, Canadian, and GFS
Ensemble mean show the earliest turn and show Irma moving east of
the coast of Florida toward the southeastern United States. The
new forecast track will best follow the ECMWF, as well as the
Florida State Superensemble and the HFIP Corrected Consensus, and
it calls for the center to move over portions of the southeastern
Florida Peninsula between 72-96 h and then across the Atlantic into
southern South Carolina by 120 h. Users are again reminded not to
focus on the exact track since the average NHC track errors at days
3, 4, and 5 are about 120, 175, and 225 miles, respectively.

UKMet ensembles

Heard stated several times last night on TWC that some on the Fl West Coast might want to let their guard down. But should not do this. The Euro track is most likely, but it could still shift a tad west, think that's much more likely than east. You still can't rule Irma sliding north along the coast somewhere near Naples and south of Ft Myers. Has to be considered.

[Tammster]

From the 5AM discussion:

The timing of the turn is the most important question and one still filled with
uncertainty. The UKMET, UK Ensemble mean, and the NAVGEM are the
models showing the latest turn, and they forecast Irma to move into
the southeastern Gulf of Mexico and near the west coast of the
Florida Peninsula. The ECMWF and ECMWF Ensemble mean are in the
middle of the model pack and show Irma moving over the southeastern
portion of the Florida Peninsula. The GFS, Canadian, and GFS
Ensemble mean show the earliest turn and show Irma moving east of
the coast of Florida toward the southeastern United States. The
new forecast track will best follow the ECMWF, as well as the
Florida State Superensemble and the HFIP Corrected Consensus, and
it calls for the center to move over portions of the southeastern
Florida Peninsula between 72-96 h and then across the Atlantic into
southern South Carolina by 120 h. Users are again reminded not to
focus on the exact track since the average NHC track errors at days
3, 4, and 5 are about 120, 175, and 225 miles, respectively.

UKMet ensembles

Heard stated several times last night on TWC that some on the Fl West Coast might want to let their guard down. But should not do this. The Euro track is most likely, but it could still shift a tad west, think that's much more likely than east. You still can't rule Irma sliding north along the coast somewhere near Naples and south of Ft Myers. Has to be considered.

Isn’t this the model that best predicted Matthew?

[chris_fit]

Good Morning.

This Morning's Ensembles:

EURO


GFS

[Michele B]

It's all about "the turn." Literally I would think it's still a crap shoot until Irma makes that turn. And there's no way - with the current technology we have - to understand exactly how much influence the ridges and troughs have on a storm. Oh, we DO now know they are pushed or pulled by them, but does a Stronger storm feel antrough more than a weaker one? Does a ridge cause strengthening in a weaker storm more than not?

Is the influence exactly the same based on how close the
Ridge is to every storm? There's
So much we're still speculating about because the science hasn't evolved that far yet.

And I'm sure it has to have something to do with how high up the cloud tops
Are as to how much the upper jet stream has influence on a storm. Does that change storm to storm based on each storm's internal structure?

[Voltron]

It's all about "the turn." Literally I would think it's still a crap shoot until Irma makes that turn. And there's no way - with the current technology we have - to understand exactly how much influence the ridges and troughs have on a storm. Oh, we DO now know they are pushed or pulled by them, but does a Stronger storm feel antrough more than a weaker one? Does a ridge cause strengthening in a weaker storm more than not?

Is the influence exactly the same based on how close the
Ridge is to every storm? There's
So much we're still speculating about because the science hasn't evolved that far yet.

And I'm sure it has to have something to do with how high up the cloud tops
Are as to how much the upper jet stream has influence on a storm. Does that change storm to storm based on each storm's internal structure?

Very good commentary and I agree that turn is the key. GFS and yes it has faults but keeps sniffing a rossby ridge that is behind the trough and lifts out sooner which would put the storm further east, only time will tell while the ridge is giving away sooner. Euro is big brother but even big brother gets beat every now and then. Several models have this a bit east as well others to the west. This is all interesting and key is that northern turn. When and where. I am hoping for the GFS in order to help FL . Sometimes when I read this it seems like others really want a FL landing. Models are really still open which is inteesting for this time

[Michele B]

...

Very good commentary and I agree that turn is the key. GFS and yes it has faults but keeps sniffing a rossby ridge that is behind the trough and lifts out sooner which would put the storm further east, only time will tell while the ridge is giving away sooner. Euro is big brother but even big brother gets beat every now and then. Several models have this a bit east as well others to the west. This is all interesting and key is that northern turn. When and where. I am hoping for the GFS in order to help FL . Sometimes when I read this it seems like others really want a FL landing. Models are really still open which is inteesting for this time

Yes, you are correct there is a lot of "wishful thinking" going into some local forecasts. That's when I'm thankful there's computer models at all!

[NDG]

This morning I can't believe some TV stations, I wouldn't say who, here in the Orlando area are still giving false hopes to coastal area residents by the showing the tropical models' track east of coastal central FL and saying that "we" hope they keep shifting east. So the average resident will think that this will be just another Matthew.

[pgoss11]

It's looking more and more like a no win situation for the SE US. While a direct hit on Miami lessens the blow for us in the Carolinas, just a slight miss to the east of Miami would be bad for us here n the Carolinas. Praying for you guys down there in Florida.

[fendie]

I noticed the ECMWF/Euro is verifying quite well out to 96 hours so I will share what the WxBell 0.1 degree/10 km hi-res 6-hourly 0Z Euro run looks like from approximately 13 hours before first Florida landfall thru 144 hours.

At 72 hours (Saturday Sept 9th 8 pm EDT) it's 150 miles Southwest of Miami, FL at 924 mb with maximum 10-meter winds of 90 knots/103 mph and gusts to 160 mph. Euro model error ~100 miles at 72 hours.

At 78 hours (Sunday Sept 10th 2 am EDT) it's miles 75 miles South of Miami, FL at 918 mb with maximum 10-meter winds of 85 knots/99 mph and gusts to 162 mph. That's 60 miles Northwest with a 6-hour average speed of 10 mph.

First Contenintal US landfall on 0Z Euro is at approximately 85 hours (Sunday Sept 10th 9 am EDT) on Islandia, FL/Elliot Key, FL and 25 miles S of Downtown Miami at approximately 925 mb with maximum 10-meter winds of approximately 88 knots/101 mph and gusts to approximtely 160 mph. That's 60 miles a hair west of due North with a 6-hour average speed of 10 mph.

For reference, at 84 hours out on Sunday Sept 10th at 8 am EDT, the 0z GFS has Irma approximately 60 miles a hair south of due East of the 0Z Euro forecast point for the same time. The 0Z GFS has Irma at 898 mb with maximum 10-meter winds of 116 knots/133 mph and gusts to 157 mph. Irma then landfalls an hour or two later on a due north path over the Cat Cays and then the Bimini Islands in the far western Bahamas. The difference bettween the 0z Euro/GFS regarding wind gusts in Miami are GFS has approximately 80-90 mph gusts Sunday morning thru early evening, whereas Euro has 80-90 mph gusts starting around 2 am EDT Sunday morning and 110-150 mph gusts during the day, with 80-90 mph gusts ending after sunset Sunday night. The 6Z GFS has Irma 50 miles Northwest of the 0Z GFS run for Sunday Setember 10th at 8 am EDT and 50 miles Northeast of the 0Z Euro forecast position. The new 6Z GFS forecast center is located 15 miles due West of the Bimini Islands Sunday at 8 am EDT. 6Z GFS mimimum pressuren is 899 mb with maximum 10-meter winds of 111 knots/128 mph and gusts to 150 mph. Irma then continues North and landfalls at approximately Monday Sept 11th 3 pm EDT around St Helena Island, SC or 45 miles Southwest of Charleston, SC or 45 miles Northeast of Savannah, GA. Minimum pressure at approximately 907 mb with maximum 10-meter winds of 103 knots/120 mph and gusts to 140 mph. Irma approaches St Helena Island, SC with a NNW heading at 15 mph and after 6 hours at 8 pm EDT Monday night it's travelled 90 miles inland to over Branchville, SC or 50 miles South of Columbia, SC.

Back to the 0Z Euro, extrapolating movement Irma then moves 80 miles nearly due North at a 6-hour average speed of 13 mph (from 84-90 hours) for a second landfall on downtown Miami at approximately 88 hours or Sunday Sept 10th at 11 am EDT. That's approximately two hours after the first FL landfall in Islandia. I hope any thrill seekers who find themselves in high winds don't glue their attention to their cameras; there are a plethora of webcams and mechanisms that don't require a human to put themselves and emergency managers/first responders at further risk just to get getting another camera eye on the little blue sheds. Nevertheless, it seems imminent there will be some devestating footage regardless of the exact path of the eye but the consensus of the recent Euro and other recent guidance is saddening for many people from Florida to the Carolinas and parts of The Bahamas.

At 90 hours (Sunday Sept 10th 2 pm EDT) it's 10 miles West of Boca Raton, FL at 940 mb and with maximum 10-meter winds of 71 knots/91 mph and gusts to 152 mph. That's 80 miles a hair west of North with a 6-hour average speed of 13 mph.

At 96 hours (Sunday Sept 10th 8 pm EDT) it's reemerging over water over Roseland, FL or 15 miles SSE of Melbourne, FL at 948 mb with maximum 10-meter winds of 71 knots/82 mph and gusts to 138 mph. That's 100 miles NNW with a 6-hour average speed of 16 mph. Euro model error ~130 miles at 96 hours.

At 102 hours (Monday Sept 11th 2 am EDT) -- dark outside; moonrise at 11:39 pm EDT with 70% illumination until moon set at 1:15 pm EDT), it's 20 miles NNW of Cape Canaveral, FL at 953 mb with maximum 10-meter winds of 70 knots/80 mph and gusts to 125 mph. That's 70 miles North with a 6-hour average speed of 12 mph (the musician Conor Oborst has a song about Cape Canaveral and an album with a few references to hurricanes).

At 108 hours (Monday Sept 11th 8 am EDT) It's 40 miles West of Jacksonville, FL heading on a wobbly path (probably a bad word to use, more of a beer, err veer) towards the WNW at 953 mb with maximum 10-meter winds of 76 knots/87 mph with gusts to 121 mph. That's 100 miles NNW with a 6-hour average speed of 18 mph.

At 114 hours (Monday Sept 11th 2 pm EDT) it's 15 miles North of Woodbine, GA or 40 miles North of Jacksonville, FL at 949 mb with maximum 10-meter winds of 59 knots/68 mph and gusts to 126 mph. That's 70 miles North with a 6-hour average speed of 11 mph.

At 120 hours (Monday Sept 11th 8 pm EDT) it's over Statesboro,
GA or 50 miles WNW of Savannah, GA at 975 mb with maximum 10-meter winds of 52 knots/45 mph and gusts to 87 mph. That's 90 miles North with a 6-hour average speed of 15 mph. Euro model error ~200 miles at 96 hours.

Then a day out to 144 hours (Tuesday Sept 12th 8 pm EDT) it's 100 miles Northwest of Knoxville, TN on the border with Kentucky at 1001 mb. That's 375 miles Northwest with a 24-hour average speed of 15 mph.

[Kingarabian]

This morning I can't believe some TV stations, I wouldn't say who, here in the Orlando area are still giving false hopes to coastal area residents by the showing the tropical models' track east of coastal central FL and saying that "we" hope they keep shifting east. So the average resident will think that this will be just another Matthew.

That's just terrible.

[ronjon]

This morning I can't believe some TV stations, I wouldn't say who, here in the Orlando area are still giving false hopes to coastal area residents by the showing the tropical models' track east of coastal central FL and saying that "we" hope they keep shifting east. So the average resident will think that this will be just another Matthew.

I commented on the other thread about some Miami tv stations misleading model runs. Unfortunately, we'll have to wait for NHC to clarify to the public when they post hurricane watches later this morning.

[Kingarabian]

From the 5AM discussion:

The timing of the turn is the most important question and one still filled with
uncertainty. The UKMET, UK Ensemble mean, and the NAVGEM are the
models showing the latest turn, and they forecast Irma to move into
the southeastern Gulf of Mexico and near the west coast of the
Florida Peninsula. The ECMWF and ECMWF Ensemble mean are in the
middle of the model pack and show Irma moving over the southeastern
portion of the Florida Peninsula. The GFS, Canadian, and GFS
Ensemble mean show the earliest turn and show Irma moving east of
the coast of Florida toward the southeastern United States. The
new forecast track will best follow the ECMWF, as well as the
Florida State Superensemble and the HFIP Corrected Consensus, and
it calls for the center to move over portions of the southeastern
Florida Peninsula between 72-96 h and then across the Atlantic into
southern South Carolina by 120 h. Users are again reminded not to
focus on the exact track since the average NHC track errors at days
3, 4, and 5 are about 120, 175, and 225 miles, respectively.

UKMet ensembles

[img]https://i.imgur.com/kqRFhqt.jpg[/mg]

Sadly that's the best case scenario to spare southern Florida from a high end cat.4 or a cat.5 landfall. It needs to track over Cuba and allow the land interaction to weaken it considerably. Unfortunately that also means that the Cubans would have to deal a very strong hurricane... aah. Unfortunately the worst outcomes from Irma continue to verify.

[JPmia]

 https://twitter.com/mjventrice/status/905747637642698753

[jlauderdal]

It's looking more and more like a no win situation for the SE US. While a direct hit on Miami lessens the blow for us in the Carolinas, just a slight miss to the east of Miami would be bad for us here n the Carolinas. Praying for you guys down there in Florida.

i wouldnt take an easterly solution off the table yet that stays off our coast and somehow avoids you...unlikely but until we get a better consensus on the ridge and trough dance thats going on then there is still a shot, nhc is best track and there is plenty of error..all that said, im preparing for a category 5 direct hit as should everyone else keys, se and sw florida..dont get fooled by spaghetti models, media conjecture, etc..we wont have a solid idea until it makes the turn but i would be surprised if the nhc track is off by more than 50 miles either way....also, if you are going to stay as I am doing and you live near the coast make sure you have a way to the roof in case the surge gets out of control...going in the attic isnt an acceptable plan and i now people get desperate but dont do it, its a death wish..make sure you have a ladder to get you to the roof and ideally a flotation device

[Nimbus]

Not gonna stress this enough, when the models are sparring with each other, focus on NHC. I kinda stopped watching the model tracking because it's still full of errors. What makes it wild is that no one can fully predict where Irma can go from here. Right now, I think we should just focus on NHC updates for the most part.

Agree and I very much rely on NHC vs. models but when they specifically say they are keeping their track because they are afraid the models will come west again; it makes their track not truly what they think.

Due to the severity of the storm and the possible devastation it may have in the southeastern US, the NHC opinion is being supplemented. Looking back through US history it is not uncommon for an agency providing critical information to be commandeered.

We all know that forecasting the late turn of a large storm with an approaching trough accurately is nearly impossible, and the recent model trending did actually widen the landfall cone a little more than what most of us would expect. Not much sense in trying to analyze model runs that have been commandeered either.

[tolakram]

I am reminded just how bad the GFS was for Harvey and how long it hung onto the wrong (west) solution.

[dukeblue219]

This morning I can't believe some TV stations, I wouldn't say who, here in the Orlando area are still giving false hopes to coastal area residents by the showing the tropical models' track east of coastal central FL and saying that "we" hope they keep shifting east. So the average resident will think that this will be just another Matthew.

I commented on the other thread about some Miami tv stations misleading model runs. Unfortunately, we'll have to wait for NHC to clarify to the public when they post hurricane watches later this morning.

What's a fast analogy that people will understand? I tried telling someone that living in S FL is like playing darts at a distance of 50 feet, and your face is the bullseye. Computer simulations say the dart could land on either side of your face. Would that make you feel safe?

It felt too clumsy. But we do need a fast way to explain that this isn't a case where either the EURO or GFS solution will be "right" but rather that both are saying watch out S FL.