ATL: HERMINE - Models

[WeatherEmperor]

The system behind 99L blows up into a major hurricane now. Land interaction isnt the deal breaker here. It starts weakening just before it gets the the islands so it must be atmosphere related

[GeneratorPower]

I think it's dry air ahead of and to the north of the invest which is causing the stunted growth.

[SFLcane]

The system behind 99L blows up into a major hurricane now. Land interaction isnt the deal breaker here. It starts weakening just before it gets the the islands so it must be atmosphere related

Yea atmosphere related right dust, shear, upper level lows sinking air this basin just sucks. Just took my daughter to see Petes dragon maybe we'll find a real one before the Atlantic produces a " real" bonified cane.

[chaser1]

One thing that is pretty obvious to me while looking back east to the African coastline, if one were to view the water vapor loop it seems clear that the SAL conditions are reducing and this seems to have been a trend over the previous week or longer. In fact, if it were available I'd like to see a strung together loop of the tropical atlantic for the entire prior 2 weeks. I think we'd see that the extent of dryer air has thinned very significantly. Fiona and 99L are doing their part in mixing in moist tropical air and slowly dispersing/moistening the atmosphere. The conditions east of Invest 99L might just be becomming more favorable thus models are likely seeing better dynamics for development.

[CYCLONE MIKE]

Seems the gfs is back to its old ways once again. If the first doesn't succeed, just try again. Go from a cat 5 to nothing in less than 24 hrs to oh well the next one will be a cat 4. Just when I gave it a little props for being dead on with the disturbance that gave us all the flooding last week

[JaxGator]

The system behind 99L blows up into a major hurricane now. Land interaction isnt the deal breaker here. It starts weakening just before it gets the the islands so it must be atmosphere related

Yea atmosphere related right dust, shear, upper level lows sinking air this basin just sucks. Just took my daughter to see Petes dragon maybe we'll find a real one before the Atlantic produces a " real" bonified cane.

Hope y'all had fun. In all fairness though, four years vs history tells us that this basin doesn't suck.

[SeGaBob]

It seems like it's always the next wave.

[gatorcane]

GFS and ECMWF show no development. You would think NHC lowers development chances next outlook but they may wait for the 00z guidance. Do I hear the "King Euro" bells ringing again?

[SeGaBob]

They may have models we know nothing about.

[Dean4Storms]

We are still talking well over 5 days out, just because the GFS has dropped development does not mean things can't once again change.

[Ntxw]

I don't think it's a this model win or that model wins. You're speaking long term when little things can mean big errors down the road. Plus 99L simply doesn't have the convection or thunderstorms to really consolidate for any model right now. It's still just a few passing clouds for the most part in the open ocean.

[psyclone]

My guess is the NHC stands pat. they don't need to lurch around based on every model run. 60% over 5 days still gives a very solid 40% chance of no development so that possibility has adequate representation.

[Frank2]

The GFS gets the inconsistency award for being, well, inconsistent. P.S. Speaking of hurricanes, Key largo is currently showing on TCM "Why don't you wave your gun at it, Rocco."

[SouthDadeFish]

Almost all of y'all are focusing solely on the deterministic runs. The ensemble runs matter too, folks. Many ensemble members are indeed forecasting genesis as well as the deterministic runs of the UKMET and other models. Additionally, the are other factors to be looked at besides numerical model forecasts. I think many here are getting wayyyyy too tied up on a few runs of the deterministic GFS and Euro of forecasts that are 120+ hours out. Sure, 99L may very well fall apart, but it could just as easily become a TC in a few days. I would really encourage people to start embracing the ensemble approach to weather forecasting. It is very useful. There is a great deal of uncertainty that goes into each initialization and subsequent forecast that cannot be fully captured by one deterministic run. Just something to keep in mind.

[p1nheadlarry]

One thing that is pretty obvious to me while looking back east to the African coastline, if one were to view the water vapor loop it seems clear that the SAL conditions are reducing and this seems to have been a trend over the previous week or longer. In fact, if it were available I'd like to see a strung together loop of the tropical atlantic for the entire prior 2 weeks. I think we'd see that the extent of dryer air has thinned very significantly. Fiona and 99L are doing their part in mixing in moist tropical air and slowly dispersing/moistening the atmosphere. The conditions east of Invest 99L might just be becomming more favorable thus models are likely seeing better dynamics for development.

NASA has a model for forecasting SAL ten days out, but Googling it is yielding no results. I saw it on Dr. Master's blog a few weeks ago during 97L-Earl.

[p1nheadlarry]

My guess is the NHC stands pat. they don't need to lurch around based on every model run. 60% over 5 days still gives a very solid 40% chance of no development so that possibility has adequate representation.

NHC is generally very conservative, especially when it comes to a t-wave, even if it has been designated an invest.

[Alyono]

NHC has bigger tool box than Storm2k... They had 12z Euro run prior to the 2pm update and they still increased 5 day to 60%... Gotta think if they are considering the Euro showing very little and potential future 90L blowing up affecting 99L they would begin lowering 99L's percentages at the 8pm update...

um... NHC does not have the EC prior to their 18Z TDO. The EC arrives at the same time for those who PAY for it. It starts coming in maybe 10 minutes prior to 18Z

[StrongWind]

GFS at it again going from CAT 5 monster yesterday afternoon to an open wave tonight.

So on average it'll be a Cat 2.

[perk]

Almost all of y'all are focusing solely on the deterministic runs. The ensemble runs matter too, folks. Many ensemble members are indeed forecasting genesis as well as the deterministic runs of the UKMET and other models. Additionally, the are other factors to be looked at besides numerical model forecasts. I think many here are getting wayyyyy too tied up on a few runs of the deterministic GFS and Euro of forecasts that are 120+ hours out. Sure, 99L may very well fall apart, but it could just as easily become a TC in a few days. I would really encourage people to start embracing the ensemble approach to weather forecasting. It is very useful. There is a great deal of uncertainty that goes into each initialization and subsequent forecast that cannot be fully captured by one deterministic run. Just something to keep in mind.

Great post.

[floridasun78]

i want see models show by mon and tue