2023 Global Model Runs Discussion (Out thru day 16)

[jlauderdal]

Beyond 10 days so just fantasy land, but that is one of the most disturbing tropical runs ive ever seen from the GFS, sub 930 MB cat 5 heading WNW

Many a major hurricanes have been depicted on the gfs over the years that never went nay further than "depicted". Have your plans in place at any rate, its aug. 13th and thats all the motivation you need.

[USTropics]

0z Euro has a weak vort hitting Texas:
https://i.postimg.cc/vBQ38kZv/ecmwf-z850-vort-atl-59.png
This appears to be ahead of the Caribbean wave (the one currently offshore Africa that GFS just blew up). The distinction is seen most clearly on 0z CMC, which shows all 4 potential systems:
https://i.postimg.cc/3Rsj4qK6/gem-z850-vort-atl-41.png
0z GFS doesn't have it.

It's on the GFS, right along the Texas coastline at 216 hours. Here are all 4 wave axes highlighted:


For this particular feature, I will point out it's not purely from a tropical wave. There is a low pressure area attached to a surface trough that is located near 30N59W that has been diving SW under the building subtropical ridge. This will become stretched out and how it interacts with an approaching wave is key:


This is the 72 hour ECWMF forecast with both features highlighted:

[cycloneye]

Wait until the last week of August, Derek says. He may be right.

 https://twitter.com/DerekOrtt/status/1690578576809099264

[SFLcane]

Wait until the last week of August, Derek says. He may be right.

https://twitter.com/DerekOrtt/status/1690578576809099264

Yea just too dry right now until that thick Sal plume dies down and the epac not expecting much across the Atlantic.

[gatorcane]

Doesn’t take a model to see why there shouldn’t be any development in the Atlantic any time soon. All of the rising motion and favorable conditions continue to remain over the EPAC. Look at the difference between the two basins on the infrared. No doubt El Niño is helping the EPAC:

[Blown Away]

Wait until the last week of August, Derek says. He may be right.

https://twitter.com/DerekOrtt/status/1690578576809099264

The Euro/GFS model runs we’ve been following weren’t showing much until late August anyway and CMC is usually an outlier.

[Spacecoast]

0z EPS: TD Prob = ~35% into W Gulf @Day 10....


Should bring some rain.


Euro, GFS, and NAV have chance of genesis in 4-5 days (wave #2??)

[LarryWx]

1. Today's 0Z EPS while still quite active isn't quite as active as yesterday's 12Z with the AEW now in the E MDR. It still is active with the 4 possibilities. And it is still much more active than those from the same time last year. Like night and day.

2. Today's 6Z GFS is the 7th GFS run since 7/31 with a H, this one appearing to form from a southern extension of the wave now in the E MDR. Thus it looks to me like at least the 4th GFS run with a H from this AEW. Also, today's 0Z and 6Z GFS are the first consecutive runs since 7/31 with a H. Prior to this, the closest that two GFS runs since 7/31 had a H was five runs apart:

-7/31 12Z: hit SC 8/16
-8/3 6Z: hit MX/TX border 8/16
-8/6 0Z: MDR 8/18-21
-8/9 18Z: just off SC 8/25
-8/11 0Z: just off LA 8/26
-8/13 0Z: GOM 8/26-8
-8/13 6Z: GOM 8/25-6 that hits MS 8/26-7

[Stratton23]

Havent had measurable rain here in se texas in probably 2 months, ill take a TD or a TS at this point,

[LarryWx]

For the first time recently, the UKMET has Atlantic TCG (favoring recurving from the MDR):

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 138 HOURS
FORECAST POSITION AT T+138 : 16.7N 42.6W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 19.08.2023 144 16.8N 42.7W 1009 29
0000UTC 20.08.2023 156 17.1N 43.1W 1008 31
1200UTC 20.08.2023 168 17.8N 43.8W 1007 33

[Stratton23]

12z CMC just spits out systems lol, system #1 looks to be a weak tropical storm approaching the texas coast , system #2 tries to consolidate in the caribbean and a third system out in the MDR develops as well

[chaser1]

Meanwhile, GFS's Caribbean/Gulf hurricane that it has depicted for a few runs now.... dropped from latest 12Z run.

[gatorcane]

Take it with a grain of salt as it is 264 hours out, but the GFS looks to be modeling the kind of shear you would expect with an El Niño with strong upper-level westerlies from Central America to Africa:

[chaser1]

.... and with THAT look, the only region within the basin that might take note of the "bell" ringing might be limited to the sub-tropics east of 50W. That or some MDR "low-rider" that can find a way to remain below 15N.

[Ivanhater]

Take it with a grain of salt as it is 264 hours out, but the GFS looks to be modeling the kind of shear you would expect with an El Niño with strong upper-level westerlies from Central America to Africa:

https://i.postimg.cc/sx8339PP/gfs-shear-atl-45.png

Not sure you are using the correct map. By that standard. The Epac "shear" looks worse than the Atlantic

[Ntxw]

Take it with a grain of salt as it is 264 hours out, but the GFS looks to be modeling the kind of shear you would expect with an El Niño with strong upper-level westerlies from Central America to Africa:

https://i.postimg.cc/sx8339PP/gfs-shear-atl-45.png

Not sure you are using the correct map. By that standard. The Epac "shear" looks worse than the Atlantic

On the map the EPAC shear is induced by modeled tropical cyclones in the lower lats. The Atlantic side is westerlies, two different components.

[Spacecoast]

Take it with a grain of salt as it is 264 hours out, but the GFS looks to be modeling the kind of shear you would expect with an El Niño with strong upper-level westerlies from Central America to Africa:

https://i.postimg.cc/sx8339PP/gfs-shear-atl-45.png

Not sure you are using the correct map. By that standard. The Epac "shear" looks worse than the Atlantic

Not sure I am using the correct map (vortex removed), but here is the Euro during same period...


That white spot near 20N, 60W seams to be particularly non-conducive.

[chaser1]

Take it with a grain of salt as it is 264 hours out, but the GFS looks to be modeling the kind of shear you would expect with an El Niño with strong upper-level westerlies from Central America to Africa:

https://i.postimg.cc/sx8339PP/gfs-shear-atl-45.png

Not sure you are using the correct map. By that standard. The Epac "shear" looks worse than the Atlantic

Such shear might retard EPAC development, but not eliminate genesis. When I took a closer look at the EPAC itself, that shear quickly diverts from northerly to "easterly" (such as with any very strong Easterly surge pushing off the African Atlantic coast). I could see that as initially inhibiting but less so if development were to occur a bit north of those stronger winds. It is interesting how thus far, that lower latitude westerly shear seems to divert due south over Mexico rather then plow eastward across the Southern Caribbean. That would seem more indicative of what I would expect during a Nino event.

[chaser1]

Take it with a grain of salt as it is 264 hours out, but the GFS looks to be modeling the kind of shear you would expect with an El Niño with strong upper-level westerlies from Central America to Africa:

https://i.postimg.cc/sx8339PP/gfs-shear-atl-45.png

Not sure you are using the correct map. By that standard. The Epac "shear" looks worse than the Atlantic

Not sure I am using the correct map (vortex removed), but here is the Euro during same period...
https://i.ibb.co/6nVvGpM/ea4.jpg

Looks about right. Bottom line as gatorcane was indicating is that overall shear from about 15N to 30N would suggest pretty unfavorable conditions for that swath of real estate practically stretching across the entire basin (assuming that were to verify). The fact that both EURO and the GFS depict the same gives greater credence to those potential conditions. Over the years, that is where I would then turn my focus toward those goldilocks regions where genesis might still occur under more favorable conditions.

[Ivanhater]

Take it with a grain of salt as it is 264 hours out, but the GFS looks to be modeling the kind of shear you would expect with an El Niño with strong upper-level westerlies from Central America to Africa:

https://i.postimg.cc/sx8339PP/gfs-shear-atl-45.png

Not sure you are using the correct map. By that standard. The Epac "shear" looks worse than the Atlantic

On the map the EPAC shear is induced by modeled tropical cyclones in the lower lats. The Atlantic side is westerlies, two different components.

Correct. But picking that timestamp seems to be cherry picking. Shear is quite light before and after the posted timestamp over the Gulf and western Caribbean. Gfs is still hinting at development im this are by the end of August