2021 Global Model Runs Discussion (Out thru day 16)

[toad strangler]

 http://twitter.com/AndyHazelton/status/1415095622781259777

[AlphaToOmega]

For whatever reason, the GFS have a problem with phantom storms in the Southwest Caribbean. What is it about that area that makes the GFS go crazy?

https://www.weathernerds.org/models/gefs.html?&inittype=zoom&initfield=MSLP_Surface&initcycle=12&initfhour=006&initimdimx=1050&initimdimy=685&initrange=50.000000000000:258.000000000000:0:350.000000000000&initcx1=0&initcy1=0&initcx2=0&initcy2=0&initcross=False&initsound=False&initsoundx=1&initsoundy=1&initloop=True&initoverlay=False&initlstart=000&initlend=336&initlint=6&initol1=MSLP_Surface&initol2=null&initol3=null&initol4=null&initol5=null&initcities=Off&inithgwys=Off&inittracks=On&initlows=On&initlatlon=Off

[beoumont]

Literally impossible for a tropical system to form over land

toss it

Tropical Storm Elena, 1985, formed over the mainland of Cuber; later Hurricane Elena, cat 3. Entered eastern Cuber as a depression, moving WNW. The center traversed most of the length of the island, always over land; and the pressure fell 8 mb. Become a named tropical storm while still over NW Cuber when recon. measured 50 mph winds off the n. coast of the island.

[Category5Kaiju]

By the very extreme end of July into the first three days of August at least, the GFS is showing an extremely convectively active ITCZ but nothing develop yet. That should be around the same time the MJO's favorable phase begins to set in, so perhaps that could be the next best time we could theoretically see something in the deep tropics develop?

[cycloneye]

 https://twitter.com/RyanMaue/status/1417173844918480904

[captainbarbossa19]

https://twitter.com/RyanMaue/status/1417173844918480904

This would not be the first time models have shown nothing in the Atlantic into late July/early August. I suspect they may show nothing until conditions at initialization are favorable for development. We might get away with no more storms in July, but somehow I think August is going to be quite ugly, especially towards the middle and end of the month.

[Category5Kaiju]

Yeah, so about that without another July NS...at least according to this, there's a slim chance we may need to watch the subtropics near the very end of this month....

https://weather.us/cyclone-tracks/euro/grid-americas/2021071912-240.html

[AlphaToOmega]

A weak tropical storm in the subtropics similar to Tropical Storms Bill (2021) and Claudette (2015) is shown by the operational GFS.

[Category5Kaiju]

https://i.postimg.cc/h42dM6d6/gfs-mslpa-atl-22.png
https://i.postimg.cc/X7xQfsjY/gfs-mslpa-atl-21.png
A weak tropical storm in the subtropics similar to Tropical Storms Bill (2021) and Claudette (2015) is shown by the operational GFS.

Now the key question is is it going to be just a front, or will it be possible for a part of it to break free and develop into a subtropical or tropical entity independently. I would not be surprised if nothing happens, but I also wouldn't be surprised if by next week there's a very weak but legitimate TC there. These kinds of tropical storms are very hard to predict.

[chaser1]

https://twitter.com/RyanMaue/status/1417173844918480904

This would not be the first time models have shown nothing in the Atlantic into late July/early August. I suspect they may show nothing until conditions at initialization are favorable for development. We might get away with no more storms in July, but somehow I think August is going to be quite ugly, especially towards the middle and end of the month.

Correct. Models will continue to show little.... "until they do" LOL. That seems common in most years where suddenly one or more global models will wake up suggesting potential development 3-5 days out, in spite of those same models seeing nothing the day before while looking out for the next 10 days. Just how it goes.

[Nimbus]

For whatever reason, the GFS have a problem with phantom storms in the Southwest Caribbean. What is it about that area that makes the GFS go crazy?

https://www.weathernerds.org/models/gefs.html?&inittype=zoom&initfield=MSLP_Surface&initcycle=12&initfhour=006&initimdimx=1050&initimdimy=685&initrange=50.000000000000:258.000000000000:0:350.000000000000&initcx1=0&initcy1=0&initcx2=0&initcy2=0&initcross=False&initsound=False&initsoundx=1&initsoundy=1&initloop=True&initoverlay=False&initlstart=000&initlend=336&initlint=6&initol1=MSLP_Surface&initol2=null&initol3=null&initol4=null&initol5=null&initcities=Off&inithgwys=Off&inittracks=On&initlows=On&initlatlon=Off

Its where the trade winds lighten up.
Tropical waves often slow down and sometimes develop convection and spin up south of Cuba.

[toad strangler]

For whatever reason, the GFS have a problem with phantom storms in the Southwest Caribbean. What is it about that area that makes the GFS go crazy?

https://www.weathernerds.org/models/gefs.html?&inittype=zoom&initfield=MSLP_Surface&initcycle=12&initfhour=006&initimdimx=1050&initimdimy=685&initrange=50.000000000000:258.000000000000:0:350.000000000000&initcx1=0&initcy1=0&initcx2=0&initcy2=0&initcross=False&initsound=False&initsoundx=1&initsoundy=1&initloop=True&initoverlay=False&initlstart=000&initlend=336&initlint=6&initol1=MSLP_Surface&initol2=null&initol3=null&initol4=null&initol5=null&initcities=Off&inithgwys=Off&inittracks=On&initlows=On&initlatlon=Off

The GFS is notorious for spinning up phantoms derived from modeling spurious vorticity off of the mountains of Columbia and Venezuela

[ronjon]

We might want to keep an eye on a piece of vorticity at 850 mb dropping southward off a trough into north Florida and then rotating west into the eastern GOM. None of the models develop it but all (Euro, GFS, ICON, and CMC) show the broad low retrograding into the GOM. These systems can sometimes develop in these near shore environments.

[Category5Kaiju]

We might want to keep an eye on a piece of vorticity at 850 mb dropping southward off a trough into north Florida and then rotating west into the eastern GOM. None of the models develop it but all (Euro, GFS, ICON, and CMC) show the broad low retrograding into the GOM. These systems can sometimes develop in these near shore environments.

There's also a front in the subtropics roughly 5-6 days from now that *could* spawn something if conditions and timing are ok in the subtropics; even during a suppressed phase this shows how you should always be alert on possible "popup" systems.

[AlphaToOmega]

70-80% chance of seeing a tropical storm form in the Gulf Stream

[SFLcane]

Let’s start up those engines just a bit.

[Category5Kaiju]

Let’s start up those engines just a bit.

https://i.postimg.cc/wMkhsMzH/B5-EF7-DA3-D525-4864-BBD6-9-B8-C9155-C4-D8.png

August 10? Signs of waves actually beginning to do something in the deep tropics and when the MJO should begin to exert influence in the basin? Seems somewhat plausible imho

[cycloneye]

12z GFS on long range for August 8. After this frame it does not do anything more.

[SFLcane]

12z GFS on long range for August 8. After this frame it does not do anything more.

https://i.imgur.com/obq0Q5l.png

Yeah there's quite a monsoon trough out there on the GFS. Meets a dusty/sheared graveyard quickly

[cycloneye]

GFS repeats on same date the 8th.