ATL: FLORENCE - Models

[Sciencerocks]

What a joke the gfs has become...I've been watching these models for 23 years and I think it is on par with what it could do 20 of those years ago.

What a disgrace. It once again is breaking the damn ridge down too fast.

Please pay attention to the the trend of the gfs, ecmwf, ukmet and cmc that all mostly discount this joke of a model run.

[SouthFLTropics]

Hour 228, it’s going to miss it’s chance to exit and is going to pull a Betsy or Jeanne here. One thing is for sure, the later hours on the GFS runs are sure entertaining if nothing else. If this happens Florence will rack up enough ACE for the Atlantic to overtake the EPAC.

[SouthFLTropics]

Hour 276...FINALLY, here comes the broom to sweep her out to sea. Don’t think there was ever a landfall on that run.

[seahawkjd]

Yeah finally out to sea. Look at how massive it is at 276 as it moves out.

[tolakram]

6Z GFS

[tarheelprogrammer]

What a joke the gfs has become...I've been watching these models for 23 years and I think it is on par with what it could do 20 of those years ago.

What a disgrace. It once again is breaking the damn ridge down too fast.

Please pay attention to the the trend of the gfs, ecmwf, ukmet and cmc that all mostly discount this joke of a model run.

It could be right and they all start trending OTS. GFS has been right a few times recently to score a win.

[seahawkjd]

Also note it doesn't develop #9 at all and just sends it into Central America. Last model run developed it and killed it over Haiti. I wonder what is causing all that and what role it might play in influencing Flo.

[Hammy]

What a joke the gfs has become...I've been watching these models for 23 years and I think it is on par with what it could do 20 of those years ago.

What a disgrace. It once again is breaking the damn ridge down too fast.

Please pay attention to the the trend of the gfs, ecmwf, ukmet and cmc that all mostly discount this joke of a model run.

It could be right and they all start trending OTS. GFS has been right a few times recently to score a win.

Since last year the GFS has had a severe right bias to the track (similar to the NAM in fact), Irma last year was another good example where it kept trying to recurve it out to sea when it was moving SW and even the 48-72 hour forecast had it something like 150mi east of Florida. The FV3 and CMC have consistently had more realistic scenarios track-wise.

[supercane4867]

Basically you should prefer EC over GFS 90% of the time. A broken clock can be right twice a day, but that doesn't make a reason to not go for the better one.

[tolakram]

Basically you should prefer EC over GFS 90% of the time. A broken clock can be right twice a day, but that doesn't make a reason to not go for the better one.

You should prefer the blend of models, EC, GFS, UKMET, with EC having a slightly heavier weight. To say the GFS is useless is extremely incorrect.

[sittingduck]

Hope this is the proper place to ask this but what is the difference in the ensembles of the models. For example why is the spread large between ensembles of the euro etc? Different data input?

[tolakram]

Hope this is the proper place to ask this but what is the difference in the ensembles of the models. For example why is the spread large between ensembles of the euro etc? Different data input?

My understanding is that for each ensemble member a parameter is altered to simulate different conditions. Not sure who they choose the parameters or what they are, but the general; idea is what if something is different.

[Ken711]

What a joke the gfs has become...I've been watching these models for 23 years and I think it is on par with what it could do 20 of those years ago.

What a disgrace. It once again is breaking the damn ridge down too fast.

Please pay attention to the the trend of the gfs, ecmwf, ukmet and cmc that all mostly discount this joke of a model run.

It could be right and they all start trending OTS. GFS has been right a few times recently to score a win.

Since last year the GFS has had a severe right bias to the track (similar to the NAM in fact), Irma last year was another good example where it kept trying to recurve it out to sea when it was moving SW and even the 48-72 hour forecast had it something like 150mi east of Florida. The FV3 and CMC have consistently had more realistic scenarios track-wise.

Why does it still maintain a severe right bias compared to the other models? What factors do you think contribute to that? I have read here many posts about the GFS's underestimated the strength of ridges, is that part of it.

[jlauderdal]

Hope this is the proper place to ask this but what is the difference in the ensembles of the models. For example why is the spread large between ensembles of the euro etc? Different data input?

they change parameters and see how it affects the outcome and thus you see the results, its very useful and good for spotting trends, sometimes the outliers are on to something too so dont completely ignore that...best to take all this data and look for trend..."trend is your friend"....its been trending to the left for a day now and the guidance from the models isnt very consistent and they havent sent recon out yet so many scenarios on the table..what we do know is the environmental conditions are very favorable as it nears the united states and thats is extremely dangerous regardless of track

[tolakram]

[p1nheadlarry]

Similar to it blowing up Irma beyond realistic proportions, the GFS showing a sub-910 hurricane directly offshore of the OBX is...unlikely.

[Dean4Storms]

Seen this movie before, some models breaking down a ridge or lessening its SW extent too much and then the TC gets much further west. If there was some longwave trough swinging off the east coast you could trust it but in this scenario if I lived from Central Florida thru the Carolina's I'd spend the weekend getting some things squared away.

[Ken711]

Basically you should prefer EC over GFS 90% of the time. A broken clock can be right twice a day, but that doesn't make a reason to not go for the better one.

You should prefer the blend of models, EC, GFS, UKMET, with EC having a slightly heavier weight. To say the GFS is useless is extremely incorrect.

How accurate is the CMC with regard to hurricane tracks, could the NHC use it in the blend? The CMC is very close to the latest UKMET track.

[p1nheadlarry]

HWRF: 938 mbs by day 4, ~ 27 N 69 W

[tolakram]

Basically you should prefer EC over GFS 90% of the time. A broken clock can be right twice a day, but that doesn't make a reason to not go for the better one.

You should prefer the blend of models, EC, GFS, UKMET, with EC having a slightly heavier weight. To say the GFS is useless is extremely incorrect.

How are accurate is the CMC with regard to hurricane tracks, could the NHC use it in the blend?

It's not. I think it is in the blend, probably just not weighted very high. The main model used is the Florida super ensembles, which we don't have access too. My understanding is it processes all the ensembles of most of the models and has some kind of scoring system as to which ones do better, which changes day to day, year to year. It always scores near the top in track accuracy. TVCN utilizes it I think, not sure.