ATL: IRMA - Models

[Otown_Wx]

How has the UKMET performed up to now with Irma? Can it be trusted?

[Alyono]

GFS has had a right bias throughout Irma

[Steve]

UK Met hits Cuba. It comes up into SW FL and one of its specific plots is NNE of Everglades City. It crosses the state on a NNE heading and exits out between Orlando and Palm Bay. It goes east of Jacksonville and landfalls between Brunswick and Charleston.

?

[Raebie]

Here's the Navgem for what it's worth:

Oh good! Another conflicting model! Lol...I don't know whether to laugh or cry. Think I'll just go to bed.

[HurricaneFrances04]

Man, the UKMET is really intent on bringing Irma to Cuba. Even the 12Z Euro backed off so. I wonder if it's sniffing something out that the GFS is missing, because it seems odd that two of the better models are on completely different sides of the NHC cone only ~72 hours out.

[txwatcher91]

For those wondering what’s different in the synoptic setup here, look at the trough in the NE. It’s trending slower causing more interaction with Irma thus a quicker N pull.

Here’s the past 4 GFS runs.


Now here are 3 runs of the NAM showing a similar trend.

[Steve]

Can someone put together a graphic for the 00z UKMET?

You can plot it on Google Maps.

[PTPatrick]

Yeah I don't like that basically the average of GFS and U.K. Is basically a cat 4/5 eastern eye wall scraping across 7 million people.

And Cuba is going to be so key for strength. The U.K. Track alone would likely save the US from a 4 or 5 landfall.

[AdamFirst]

Honestly feel like the current NHC plot is going to prevail - maybe minor shifts - in relation to the Florida peninsula.

[HurricaneFrances04]

Honestly feel like the current NHC plot is going to prevail - maybe minor shifts - in relation to the Florida peninsula.

Yes, I think there is a graphic floating around that the NHC forecast is better performing that most of the models. Stick to the experts, but it's fun to see how the pro's come up with their forecasts.

[txwatcher91]

I honestly feel like analyzing synoptics on models is a lost art and instead the focus is on the output. How close am I to the eye, did it shift east or west, how much wind, etc without looking at all the players on the field to see why a model shows a different solution and how plausible it may or may not be. Maybe I’m just old school.

[tolakram]

Second to the Euro.

https://ruc.noaa.gov/hfip/tcgen/

Click on the VERI button. Next click on the various models and days to see how they verified. Not great, not horrible.

[Aric Dunn]

well HWRF is just a tad stronger lol..

[Ken711]

For those wondering what’s different in the synoptic setup here, look at the trough in the NE. It’s trending slower causing more interaction with Irma thus a quicker N pull.

Here’s the past 4 GFS runs.


Now here are 3 runs of the NAM showing a similar trend.

Interesting. How much more influence will it have in future runs. It's causes the final landfall to move up the coast from GA/SC to SC/NC and maybe ultimately to just NC.

[Raebie]

Honestly feel like the current NHC plot is going to prevail - maybe minor shifts - in relation to the Florida peninsula.

I know there are a ton of Florida people on here, but these models fluctuations have a huge upstream impact for GA SC And SC. Frankly if you're in skinny Florida, you know you are under the gun. Three other states actually have less certainty than FL right now. That's unbelievable to me at this point.

[Bocadude85]

Looks like if we average out the UKMET and GFS, it's still pretty much in the metro Dade and Broward area.

Honestly that's what I was thinking, it you adjust the GFS 30 miles southwest to correct its north bias then you get a Florida landfall, I mean the GFS is only 30 miles offshore on the 0z run. The GFS really didn't change much from the 18z run other then the timing/speed.

[Steve]

Second to the Euro.

https://ruc.noaa.gov/hfip/tcgen/

Click on the VERI button. Next click on the various models and days to see how they verified. Not great, not horrible.

1 Hour. I'm going to try to go to sleep early tonight, but I'm sure I'll toss and turn around the time the EC is running. We're coming on 84-86 hours or so, and it's only likely to get better and better as time to landall closes. HWRF and HMON are initialized and early in their runs and on the way to mowing down some islands.

[wayoutfront]

I don't know which forecaster is up to bat tonight at the NHC

But boy do I feel sorry for them ...The 5 am forecast tomorrow is going to be one tough cookie to figure out ...

Time is will be ticking on getting a whole lot of people to safe places and ................

It's going to be very interesting how they sort out path and intensity with models bouncing around

[PTPatrick]

I honestly feel like analyzing synoptics on models is a lost art and instead the focus is on the output. How close am I to the eye, did it shift east or west, how much wind, etc without looking at all the players on the field to see why a model shows a different solution and how plausible it may or may not be. Maybe I’m just old school.

What does ukmet do with this trough that's different than gfs?

[USTropics]

Average positional error by model through 120 hours for IRMA:


Model bias at 72, 96, and 120 hours for IRMA: