2020 Global Model Runs Discussion (Out thru day 16)

[LarryWx]

I'm starting to wonder if the GFS para is a genesis happy model like the CMC.

The Euro seems to be a genesis unhappy model these days. Split the difference?

Can't we just have an emotionless model when it comes to genesis?

[Astromanía]

The 6Z GFS Parallel has us on the V storm by September 17th

[url]https://i.postimg.cc/026RQZXC/5-C0-E9-BC2-5921-44-BB-867-B-4834948574-E3.gif [/url]

Whats that major coming to my area at september 17th

[ThetaE]

I'm starting to wonder if the GFS para is a genesis happy model like the CMC.

The Euro seems to be a genesis unhappy model these days. Split the difference?

Can't we just have an emotionless model when it comes to genesis?

Sadly, this is probably a long ways away from happening...

For those interested in more of the nuts and bolts of the parallel model, here's a link to retrospective forecasts of past TCs, comparing the operational ("GFSv15") and parallel ("GFSv16") models to one another, and to observations/analysis: https://www.emc.ncep.noaa.gov/users/meg/gfsv16/retros/

Some powerpoints walking through these case studies can also be found by navigating to the "GFSv16 Official Evaluation Page." The general takeaway is that the parallel GFS captures intensification in unexpected RI storms (e.g. Dorian, Michael) at longer lead times than the operational model, but that the parallel has a "tendency to strengthen all TCs that develop in both basins" and has a fast and poleward bias. It doesn't look like these studies focused much on cases where genesis was predicted but didn't materialize, but you're probably right that the GFS parallel is too eager (I mean, 6 new storms by the 17th? ).

[Ivanhater]

That huge trough from yesterday completely breaks down and is replaced with a huge ridge for the Southeast on today's run. Much more believable

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[northjaxpro]

That huge trough from yesterday completely breaks down and is replaced with a huge ridge for the Southeast on today's run. Much more believable https://uploads.tapatalk-cdn.com/20200901/f42047d1bcc3fb3b64b4d62fc891ab57.jpg

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Potentially could have either Omar(if T.D. 15 isn't upgraded)
or Paulette on this run approaching the Northern Lesser Antilles.

Big ridge looks to establish itself once again on this run.This is one potential cyclone we really have to watch next week.

[NDG]

How about that early fall pattern for the eastern US? Nothing but wishful thinking as continued shown by the ensembles, unfortunately but not surprising to some of us.

[northjaxpro]

How about that early fall pattern for the eastern US? Nothing but wishful thinking as continued shown by the ensembles, unfortunately but not surprising to some of us.

NDG , not at all to me either.

[EquusStorm]

Considering the trend of immediately retiring replacement names, Paulette will definitely be one to watch lol

[St0rmTh0r]

At this point we are playing ourselves to the point of insanity if we believe the long range euro and gfs pattern

[northjaxpro]

At this point we are playing ourselves to the point of insanity if we believe the long range euro and gfs pattern

Also, latest teleconnections index forecast has a very strong + NAO right through Sept 10, possibly longer. So, yeah, strong ridging will be likely.

[NDG]

Euro ensembles show potentially 2-3 systems at the same time over in the Atlantic basin during the peak of the season.

[SFLcane]

Euro ensembles show potentially 2-3 systems at the same time over in the Atlantic basin during the peak of the season.

https://i.imgur.com/LSAtgYI.png

Interesting westward bend on those ensembles nearing the Bahamas.

[LarryWx]

Continuing further out on the 12Z EPS from what NDG just posted: suggests the CONUS, Bahamas, and Bermuda should be wary about midmonth from the wave coming off the African coast about now:

[NDG]

12z EPS.

[SFLcane]

Continuing further out on the 12Z EPS from what NDG just posted: suggests the CONUS, Bahamas, and Bermuda should be wary about midmonth from the wave coming off the African coast about now:

https://i.imgur.com/F2SeZ4A.png

EPS trended a bit SW from 00z but still implying a potential threat to Bermuda.

[SFLcane]

12z EPS.
https://i.imgur.com/TNO6hf9.gif

Just enough to weaken the ridge and allow for a potential storm to threaten Bermuda or head out to sea. This will continue change

[gatorcane]

The GFS parallel still shows the trough in the 12Z run:

[NDG]

12z EPS.
https://i.imgur.com/TNO6hf9.gif

Just enough to weaken the ridge and allow for a potential storm to threaten Bermuda or head out to sea. This will continue change

That's not the way to look at it, usually on the ensembles the anomalies become less drastic on its long range image because there is less agreement on the exact position of the ridge, but not that it will weaken. The ridge will most likely still be there & strong somewhere between the SE US & Bermuda.

[NDG]

The GFS parallel still shows the trough in the 12Z run:

https://i.postimg.cc/9FsmF9GN/gfsp-z500a-us-32.png

GEFS-Parallel has the trough slightly weaker and negative tilted west, slightly more east than the GEFS.



GEPS agrees with the Euro of positioning it further west.

[TheStormExpert]

Euro ensembles show potentially 2-3 systems at the same time over in the Atlantic basin during the peak of the season.

https://i.imgur.com/LSAtgYI.png

Besides the current two?