ATL: FLORENCE - Models

[tolakram]

Model plots. Keep in mind this shows a bunch of models regardless of skill. All models are NOT equal.





Source: https://www.sfwmd.gov/weather-radar/hurricane-model-plots

[dspguy]

Model question:

What's the difference between the MSLP & 10m Wind model and the MSLP & 850hpa Wind model? I get that one is showing wind speed near the surface? And the other... the wind speed at cloud level?

Basically you got that correct.

Ok, so if there's 90mph winds many thousands of feet up but only 30mph winds hitting the trees nearby, should I be concerned about 90mph thousands of feet up?

[AJC3]

Model question:

What's the difference between the MSLP & 10m Wind model and the MSLP & 850hpa Wind model? I get that one is showing wind speed near the surface? And the other... the wind speed at cloud level?

Basically you got that correct.

Ok, so if there's 90mph winds many thousands of feet up but only 30mph winds hitting the trees nearby, should I be concerned about 90mph thousands of feet up?

The answer to that would be "a little", since sustained 30 MPH winds usually gust to around 50 MPH or so, which can cause some minor damage.

However, your hypothetical example isn't how TC winds work - 90 MPH flight level (either 5KFT or 10KFT) winds around a TC will translate into much stronger surface winds than 30 MPH.

[edu2703]

12z NAM

[Bocadude85]

The 12Z GFS is quite a bit southwest of the 6z at 54 hours

[url][/url]

[chris_fit]

12 GFS is coming in a good ways SOUTH. I hope people in SC are watching this VERY VERY closely...

[edu2703]

12z GFS trending southwest. Looks like we will have a model consensus

[KWT]

Well its taken many days and dozens of runs...

BUT FINALLY...the GFS has given in and shifted SW towards the other models. Its just offshore at 60hrs and rapidly slowing down, looks like a hit for S. NC.

Hope the person who has been on this thread who was supporting the GFS/other OTS runs has prepared and listened to the NHC, who have done just an outstanding job with this one.

[tallywx]

The GFS caved. Wow.

This is what happens when you start being able to sample the upper air pattern for systems coming ashore in the Pacific Northwest. I almost think one should do sampling flights over there since it’s those systems that define all the ridges and troughs downstream.

[KWT]

The GFS caved. Wow.

As some of us very old hands have been telling people, the GFS has got some serious right side bias. That combined with occasionally unrealistic pressures combines to ensure the GFS can be a poor model in set-ups with strong upper ridging.

Interesting the FV3 has been almost as outstanding as the ECMWF/NHC have been, which is surely a good sign for the future.

[jlauderdal]

The GFS caved. Wow.

No surprise here, several of us have been saying since Saturday it is biased to the right, it could still be correct but we are getting close to the point of no return

[supercane4867]

12z GFS has CAT4 landfall near Cape Fear and stalls just inland.

[Vdogg]

CMC went way North with an OBX hit. GFS went way south with an NC/SC border hit. GFS is now south of the Euro and FV3.

[Bocadude85]

Looking at the 0Z ECMWF ensembles I would not be surprised if Florence landfalls somewhere between Charleston and Myrtle Beach, just my opinion of course.

[Bocadude85]

CMC went way North with an OBX hit. GFS went way south with an NC/SC border hit. GFS is now south of the Euro and FV3.

The 12z CMC is west of the 0z run by a decent amount, no real change in latitude though.

[crimi481]

Do the models consider the low pressure in the gulf? Would Flo be drawn more sw to low pressure - as it will be blocked from north by ridge?

[Blinhart]

expected wind arrival - https://www.nhc.noaa.gov/refresh/graphi ... 4#contents

spaghetti models - https://apps.sfwmd.gov/sfwmd/common/ima ... 06_ens.gif

wind probabilities - 1. https://www.nhc.noaa.gov/refresh/graphi ... #wcontents
2. https://www.nhc.noaa.gov/refresh/graphi ... #wcontents
3. https://www.nhc.noaa.gov/refresh/graphi ... #wcontents

Key messages - https://www.nhc.noaa.gov/storm_graphics ... ges_sm.png

[MGC]

12Z GFS is much more believable. No crazy cat-5 loops off Hatteras....MGC

[tolakram]

12Z GFS

[pgoss11]

Looking at the 0Z ECMWF ensembles I would not be surprised if Florence landfalls somewhere between Charleston and Myrtle Beach, just my opinion of course.

I was really surprised to see the 0Z ECMWF ensembles. I wouldn't be surprised to see landfall closer to Myrtle Beach.