ATL: IRMA - Models

[tolakram]

It means that it might go east than forecasted.
It's based off of the last runs.

What's his experience and verification record compared to the NHC. He might be awesome but I'm skeptical of skeptics this late in the game. The GFS error rate is large and has been right of actual track almost constantly, if not constantly.

[NDG]

That model bias map is fascination...EVERY single model has been too far east...hmm...

Model bias map? Could you repost?

Positional error by forecast hour:


Model positional bias:


You can find these type of charts here - http://www.atmos.albany.edu/facstaff/tang/tcguidance/

The usual trusted models that have been right biased with Irma is making the NHC track not the best on their 5 day position, the Euro is kicking butt! Unfortunately for FL though.

[tolakram]

Hey all,

this late in the game let's keep the random tweets and other questionable information out. Unfortunately we have some folks clinging to the models thread thinking they can out forecast the NHC, and while these folks are just discussing possible outcomes as forecasters do I don't think it works well here. In other words, be careful with your sources.

Hopefully that makes sense.

[Steve]

Did the GEFS ensembles shift west again? Sorry guys I just woke up, we are doing final preps for evacuation.

We leave tonight.

storm is still days away. That cone could slide to bermuda or Brownsville. Ive seen it happen...the cone is self correcting..so it looks like its never wrong. Its really only 99% accurate 24 hours out...and even then you get situations like Charlie where it turns direction at the last minute

Effects in 2, landfall possibly in 3. You're not going to see the cone slide to Bermuda or Brownsville this time. Auto is a good poster, and if he has made the decision to get out ahead of the rush, you should probably be applauding him rather than eye-rolling. Everyone knows their unique situation. He's been watching the models and NHC and is making an informed and intelligent decision. If there is a benefit from this site besides learning, is that some people will make responsible decisions that may save their lives or the lives of their loved ones. I'm not meaning to sound like I'm bagging on you, because I'm not. I just think you should have probably not dissed on him for a potentially smart move.

NAM 12km is out to 45 hours. It's much farther SW near the Northern Coast of Cuba at 45 hours. You figured it would come around to a more realistic track by about 72 hours. Canadian Ridge is pushing harder east against the slightly smaller NE Trough from 06Z. This run will likely finish much closer to Florida than the last several.
https://www.tropicaltidbits.com/analysi ... 0&ypos=366

[eastcoastFL]

Did the GEFS ensembles shift west again? Sorry guys I just woke up, we are doing final preps for evacuation.

We leave tonight.

Looks that way. Just got to my final destination. Safe travels!

[caneman]

Did the GEFS ensembles shift west again? Sorry guys I just woke up, we are doing final preps for evacuation.

We leave tonight.

storm is still days away. That cone could slide to bermuda or Brownsville. Ive seen it happen...the cone is self correcting..so it looks like its never wrong. Its really only 99% accurate 24 hours out...and even then you get situations like Charlie where it turns direction at the last minute

Effects in 2, landfall possibly in 3. You're not going to see the cone slide to Bermuda or Brownsville this time. Auto is a good poster, and if he has made the decision to get out ahead of the rush, you should probably be applauding him rather than eye-rolling. Everyone knows their unique situation. He's been watching the models and NHC and is making an informed and intelligent decision. If there is a benefit from this site besides learning, is that some people will make responsible decisions that may save their lives or the lives of their loved ones. I'm not meaning to sound like I'm bagging on you, because I'm not. I just think you should have probably not dissed on him for a potentially smart move.

NAM 12km is out to 45 hours. It's much farther SW near the Northern Coast of Cuba at 45 hours. You figured it would come around to a more realistic track by about 72 hours. Canadian Ridge is pushing harder east against the slightly smaller NE Trough from 06Z. This run will likely finish much closer to Florida than the last several.
https://www.tropicaltidbits.com/analysi ... 0&ypos=366

Is there truth to the NAM being spectacular at 48 hour synoptics Steve?If so, it's getting me a bit more concerned on the west cost of Florida. Well that and the UKMET and Euros trend West. Thanks

[Steve]

FWIW, Eric Webb is mentioning about how GFS is showing the east outlier because of a slow down in the trough.

It's subtle, but as noted in the other post, NAM is going the other way. If you click "previous run" and look at the comparison of the 06Z to the 12Z, the edge of the red where it shows northern high pressure is along the eastern shore of Lake Michigan through the northern half of the State of Michigan at 45 hours. So trough is faster lifting out though NAM will probably still be right biased with Irma even though it positions it more southwest through 51 hours than it was at 06z.
https://www.tropicaltidbits.com/analysi ... 0&ypos=366

Still running and has about 30 hours to go.

[tolakram]

I posted this in the discussion thread, will re post here.

Due to the angle of Irma the little errors in track make a much bigger difference than they did with Matthew. Ride the archive snake linked below, look at the track errors as it approached the coast, and decide if you're comfortable with your decision (whoever you may be).

http://www.nhc.noaa.gov/archive/2016/graphics/al14/loop_3NLW.shtml

[chris_fit]

Did the GEFS ensembles shift west again? Sorry guys I just woke up, we are doing final preps for evacuation.

We leave tonight.

Looks that way. Just got to my final destination. Safe travels!

06Z GFS Ens... Decent ways west - Only 2 keep it offshore now.

[gatorcane]

BIG shift west by NAM closer to the reliable models:

[SEASON_CANCELED]

Did the GEFS ensembles shift west again? Sorry guys I just woke up, we are doing final preps for evacuation.

We leave tonight.

storm is still days away. That cone could slide to bermuda or Brownsville. Ive seen it happen...the cone is self correcting..so it looks like its never wrong. Its really only 99% accurate 24 hours out...and even then you get situations like Charlie where it turns direction at the last minute

Effects in 2, landfall possibly in 3. You're not going to see the cone slide to Bermuda or Brownsville this time. Auto is a good poster, and if he has made the decision to get out ahead of the rush, you should probably be applauding him rather than eye-rolling. Everyone knows their unique situation. He's been watching the models and NHC and is making an informed and intelligent decision. If there is a benefit from this site besides learning, is that some people will make responsible decisions that may save their lives or the lives of their loved ones. I'm not meaning to sound like I'm bagging on you, because I'm not. I just think you should have probably not dissed on him for a potentially smart move.

NAM 12km is out to 45 hours. It's much farther SW near the Northern Coast of Cuba at 45 hours. You figured it would come around to a more realistic track by about 72 hours. Canadian Ridge is pushing harder east against the slightly smaller NE Trough from 06Z. This run will likely finish much closer to Florida than the last several.
https://www.tropicaltidbits.com/analysi ... 0&ypos=366

I wasn't dogging him but he is in a safer area than most right now on the west side. The rolleyes was for the charlie move in 2004 that stunned the world

[tolakram]

I wasn't dogging him but he is in a safer area than most right now on the west side. The rolleyes was for the charlie move in 2004 that stunned the world

13 years ago. I think things have improved a tad.

[gatorcane]

12Z NAM over South Florida:

[caneman]

I posted this in the discussion thread, will re post here.

Due to the angle of Irma the little errors in track make a much bigger difference than they did with Matthew. Ride the archive snake linked below, look at the track errors as it approached the coast, and decide if your comfortable with your decision (whoever you may be).

http://www.nhc.noaa.gov/archive/2016/graphics/al14/loop_3NLW.shtml

Thanks.

[opticsguy]

I was going to post about the NAM but you beat me to it. Huge shift between runs.

[gtalum]

11 AM NHC forecast track seems to be slightly further east than 5 AM.

[Steve]

Is there truth to the NAM being spectacular at 48 hour synoptics Steve?If so, it's getting me a bit more concerned on the west cost of Florida. Well that and the UKMET and Euros trend West. Thanks

Sometimes, sometimes not so much. It's sketchy. However, I think this run is fairly legitimate compared to the prior runs that had it well east of Florida. It hits the Everglades this time and comes up a little west of Miami. It may correct back a little closer east down the line. At 72 hours, 12z has made a major move to the SW from 06Z from around Jupiter, FL to south of the tip. Pretty random to see a 100 mile shift or more in a 6 hour run. NE Trough is off the US East Coast at 72 hours where it was previously around Long Island.

[Ken711]

12Z NAM over South Florida:

I can't find the 12Z NAM on tropical tidbits only the 6Z.

[Steve]

It's there. You might need to refresh or something.

[BucMan2]

Gator-

How reliable is the Nam and how much credence does the NHC give it? It looks like it is actually over SW FL or the middle of the tip?
Your thoughts?

Craig