ATL: FLORENCE - Models

[chris_fit]

Anyone have the UKMET 12Z Ensembles?

[Blown Away]

GFS @ day 10... Look at how wacky the timing is... GFS struggling from day 6-10...

[MetroMike]

12z GFS... I think GFS is underestimating ridge and/or moving Flo to fast... That's a crazy loop that I'm 99% sure won't happen...

Correct, the GFS was right biased last year with Hurricane Irma. It continues to be a fault of the model.

[AdamFirst]

Category 5 drifting southeast off the Outer Banks...next please

Looking forward to the 00z suite.

[Hypercane_Kyle]

The UKMET/CMC shifts didn't strike me as very unreasonable nor as significant deviations from the current forecast, more like they were shifting to be in line with the NHC/ECMWF. The GFS just seems like an outlier.

It's a positive trend that the GFS is being consistent with its solution, at least for two runs.

[Emmett_Brown]

I don't know if the data from the recon mission to measure the conditions around Florence will really have much affect on the models 6 days out from landfall. The ridge that is supposed to set up off the east coast won't arrive until late Tuesday. Measuring the conditions in the Pacific would probably help more. However, I suppose it will help models deal with the short term 24-72 hour motion, so it probably can't hurt. Am I wrong?

[storm4u]

At 2pm nws offices will be doing balloon launches which will help greatly for tonight's models

I don't know if the data from the recon mission to measure the conditions around Florence will really have much affect on the models 6 days out from landfall. The ridge that is supposed to set up off the east coast won't arrive until late Tuesday. Measuring the conditions in the Pacific would probably help more. However, I suppose it will help models deal with the short term 24-72 hour motion, so it probably can't hurt. Am I wrong?

[Hypercane_Kyle]

TIL that the GFS doesn't model ocean coupling/water upwelling, which causes monster Cat 5 hurricanes at ridiculous latitudes.

[hurricaneCW]

12z GFS... I think GFS is underestimating ridge and/or moving Flo to fast... That's a crazy loop that I'm 99% sure won't happen...

Correct, the GFS was right biased last year with Hurricane Irma. It continues to be a fault of the model.

It's had a right bias for Florence's entire run.

[Bocadude85]

We see these type of shifts every year, more noticeably with east coast storms, the models start converging on a area and then all of a sudden they shift northeast for a few cycles and then once upper air data is ingested into them they shift back southwest. From my experience the ridge almost always ends up being stronger then the models forecasted once it has been sampled. Go and check out the storm archives and look at the model threads..

[artist]

12z GFS... I think GFS is underestimating ridge and/or moving Flo to fast... That's a crazy loop that I'm 99% sure won't happen...

Correct, the GFS was right biased last year with Hurricane Irma. It continues to be a fault of the model.

It's had a right bias for Florence's entire run.

I believe it had a right bias with Maria as well.

[NC George]

One more shift like that and it is offshore. Tonight will be the night which tells me whether I will need to fill up my gas tank and get supplies or not tomorrow. If they shift again then I have seen this story here in the Carolinas for the past 20 years or so since Floyd. Major threats to this area seem to end up being OTS before it is all said and done. Tonight is important!

That was my thinking over the past few decades as well. Something aiming towards NC 6 days out was OTS for sure, and it was storms predicted for Florida (such as Floyd) that concerned me. However, the models have gotten significantly better over the past decade, and seem to have eliminated some of the left bias they used to manifest.

[robbielyn]

i wonder if it is possible for 94L to cause some kind of weakness causing Flo to follow 94L as their outer bands are close to each other. Any thoughts?

[p1nheadlarry]

12z GFS has a 917mb hurricane drifting SW off the coast by 192 hours. I'm sorry, but I seriously don't buy it.

Not just that, but after arriving at 943, stalling a bit looping and dropping to 917. You got the labrador current there and lots of baroclinic instability in the ocean, upwelling much?

[Blinhart]

12z GFS has a 917mb hurricane drifting SW off the coast by 192 hours. I'm sorry, but I seriously don't buy it.

Not just that, but after arriving at 943, stalling a bit looping and dropping to 917. You got the labrador current there and lots of baroclinic instability in the ocean, upwelling much?

With the flow out there, the current underneath moves at a good pace, shouldn't have much upwelling.

[meriland29]

It looks like GFS is nudging her more and more offshore since 06z. It is interesting to note though that CMC still drives her. It will be interesting to see Euro coming up.

Does this new GFS trend seem likely ? I am at work so have limited access to more intricate model predictions in terms of the ridge vs a weakness.

[tarheelprogrammer]

GEFS appears to have shifted north as well.

JMA trended south.

[PandaCitrus]

Are the models good at forecasting the size of the storm? Has Florence grown since it lost its core? It was a fairly small compact hurricane. If that is the characteristic of this storm, it could ramp up to Cat 5 very quickly but also have a much limited impact. There are fairly large sections of the South Carolina and North Carolina coast with low population densities. It's not built up like Florida. If it hits a lucky spot as a compact storm, it could have limited impacts.

[Blown Away]

12z ECMWF/Euro initialized. Looks good. Let's go!

[drewschmaltz]

12z ECMWF/Euro initialized. Looks good. Let's go!

yes, init was absolutely spot on the current position.