ATL: IRMA - Post-Tropical - Discussion

[LAwxrgal]

GFS for several runs now (including the latest 12z) has gone with an explosive deepening phase once the storm leaves Cuba. While the actual number may probably be overdone, the trend itself is worrying. I hope everyone in the warned area is prepared to have a monster on their doorstep, but I hope it doesn't actually come to pass. Godspeed.

[Exalt]

Miami dade and broward down to 10% chance of hurricane force it's now more like a TS event down here. Glad serious impacts not expected here

I wouldn't disregard impact just yet. The way the eye is moving tells me SE FL isn't out of the woods at all.

[Exalt]

GFS for several runs now (including the latest 12z) has gone with an explosive deepening phase once the storm leaves Cuba. While the number may probably be overdone, the trend itself is worrying. I hope everyone in the warned area is prepared to have a monster on their doorstep. Godspeed.

Not surprised, if you see the GOES satellite you can see the eye already clearing out with convection heavily firing.

[WeatherGuesser]

I keep seeing people on other forums bragging about how they've been through this so many times before and it's really no big deal, and so on. They don't seem to understand or different this one is.

METS, is there significant reason to anticipate this returning to Cat 5 status before or at landfall?

[AutoPenalti]

NO ONE is out of the woods yet, the cone it self outlines that a little shift east would affect Metro areas with Hurricane force winds.

[stormreader]

Nice report on TWC. Storm intensity down some at Cat 3 125 mph. Forecast to be Cat 4 along Fl west coast. But weather host said he couldn't rule out it going to Cat 5 again. Storm surges at Tampa near 8 ft forecast now. 10-15 ft at Fort Myers an Naples.

[Lifeless]

 https://twitter.com/NHC_Atlantic/status/906548124889571328




NHC has begun issuing hourly updates on Hurricane #Irma. These will continue until the eye is no longer visible on U.S. Doppler Radar.

[Evil Jeremy]

Miami dade and broward down to 10% chance of hurricane force it's now more like a TS event down here. Glad serious impacts not expected here

While our wind threat has drastically decreased over the past 48 hours, were still looking at a day of sustained upper level TS winds, which can still do damage, and heavy rains.

[tolakram]

Saved radar loop

[captain1]

Long time lurker and weather nerd here - thanks to this forum I have learned so much. I do have a question about models. I have a basic, I think, understanding of how they work. What I am curious about is how they improve. I assume they incorporate actual data from a storm after the event is over and compare that to their predictions, and thereby gain reliability going forward?

not accurate at all. The computer models simply provide a numerical approximation to the Navier-Stokes equations, with sub grid scale processes paramaterized

Captain1 -- Remember that the global models are indeed global models. They aren't tracking a hurricane as a distinct entity that moves as a result of highs here, lows there, fronts coming through, and so forth, but are constantly computing how the atmosphere changes as a large continuous fluid. They're used for all kind of weather forecasting, and plotting the path of a hurricane is just one use of that data. So in that sense, the "event" is never really over. Certainly there are on-going tweaks to the computing power and to the sophistication of those computations, but someone with direct experience developing the models would have to answer if they ever make manual adjustments to process certain types of weather more realistically.

Thanks for your informative response

[Exalt]

I keep seeing people on other forums bragging about how they've been through this so many times before and it's really no big deal, and so on. They don't seem to understand or different this one is.

METS, is there significant reason to anticipate this returning to Cat 5 status before or at landfall?

I'm not a Met, but the GFS has forecasted an explosive deepening phase the past few runs consistently and if you check GOES you can see the eye already clearing out with heavy convection already beginning to fire in the eyewall again. She's also rebuilt a full white ring and is attempting a CMG already. Lastly, there isn't really much stopping her and she's over some of the warmest water she's been over yet, the only real thing potentially stopping her is time, but with the rate that she's re-intensifying already, she's likely to regain high Cat 4 or low Cat 5 status easily.

[chaser1]

Long time lurker and weather nerd here - thanks to this forum I have learned so much. I do have a question about models. I have a basic, I think, understanding of how they work. What I am curious about is how they improve. I assume they incorporate actual data from a storm after the event is over and compare that to their predictions, and thereby gain reliability going forward?

not accurate at all. The computer models simply provide a numerical approximation to the Navier-Stokes equations, with sub grid scale processes paramaterized

Welcome Captain, I think your question regarding how model accuracy is eventually improved is a legitimate one. As a self professed "weather nerd", its understandable if "a numerical approximation to the Navier-Stokes equations, with sub grid scale processes paramaterized" adds nothing to your over-all understanding of the subject. However, it may prove impressive to throw that out there while on a date; That... or even something worth pondering during a strenuous bowel movement perhaps??

[Aric Dunn]

sorry CUba.. but just stay over land

[stormreader]

Fl Gov on now. Once surge gets as high as 15ft------this is a whole new game. Much higher chance for fatalities.

[Exalt]

As you can see Irma's already built a nearly full white ring with hints of CMG inside. Explosive deepening has begun.

[floridasun78]

ok look more north movement if that movement east coast could get more wind i going keep eye on that if moving toward keywest or middle keys

[stormreader]

Saved radar loop

Well that's it. Coming off the coast now on that loop. Exiting as a 125 mph major hurricane with an incredible amount of latent energy embedded within the system since it was a pouch coming off the African coast. This is going to be a ferocious storm along the SW Fl coast IMO.

[floridasun78]

nhc evening seen north movement or nw

[LAwxrgal]

Can she have an eye wall replacement cycle (EWRC) before landfall?

[tolakram]

Could be just a wobble.