2023 Global Model Runs Discussion (Out thru day 16)

[Teban54]

A handful 0z GEFS members show a weak "Caribbean cruiser" with genesis in 5 days. One member has a borderline Cat 1 making landfall in SWFL. While support is very weak, it's more than the past 3 runs.


Otherwise, the three main ensemble models generally show the east MDR storm and the BoC storm. GEPS (CMC ensembles) is still showing some more Caribbean action in the fantasy range.

[hurricanetrack]

Featured Adrian in today's video discussion as we watch the long range models for more mischief as October rolls along...

[youtube]https://youtu.be/jTrQM5M1Xfk[/youtube]

[USTropics]

One thing is clear, El Nino is starting to dominate. Both the ECMWF and GFS have a strong subtropical jet that develops along the gulf coast states starting in a few days. This become a semipermanent feature over the course of the next week+ (this type of pattern in Fall occurs in strong El Nino seasons):


As far as implications on the feature set to cross over into the BOC that has marginal ensemble support, a few scenarios could play out. One, we could see ridging take place downstream south of the subtropical jet (i.e., a system getting trapped down in the BOC) that moves more southerly (this has the potential for a stronger system). The second scenario (and the more likely one imo), any storm that traverses into the NGOM will be moving quickly with very sheared/subtropical characteristics.

[SouthFLTropics]

With the pattern that is setting up I've got one eye on the Caribbean, GOM, and BOC but my other eye's attention has been diverted to watching the evolving pattern over the East and Southeast CONUS. Winter is coming... You can clearly see it. And by the looks of it, I'm thinking that the Southeast is in for an aggressive El Niño Winter... Cold and wet!!! I'm watching carefully to see when the Smoky Mountains will get their first measurable snowfall.

[USTropics]

I don't see much ensemble support for a hurricane. None of the 51 members of the ECMWF support a hurricane. I see 1 of 32 members on the 18z GEFS (a brief hurricane which has the southerly blocking pattern discussed above):
12z ECMWF


18z GFS


I mentioned there is only marginal ensemble support for development at this time (less than 50%) for good reasons. Before we get to a potential GOM track, we need to see if an actual cross over even occurs. There is some very high terrain a potential system has to cross over, and an equal chance that whatever does try to cross over gets buried in Mexico and dissipates before it can reach the GOM. A blend of the NCEP model ensembles has a 30-40% chance of development for this region.

[REDHurricane]

I mentioned there is only marginal ensemble support for development at this time (less than 50%) for good reasons. Before we get to a potential GOM track, we need to see if an actual cross over even occurs. There is some very high terrain a potential system has to cross over, and an equal chance that whatever does try to cross over gets buried in Mexico and dissipates before it can reach the GOM. A blend of the NCEP model ensembles has a 30-40% chance of development for this region.
https://i.imgur.com/hmd1nph.png

What is that big orange 50-60% area located off the coast of Venezuela/Colombia -- some kind of glitch or misclassification I'm guessing? Because I don't see anything resembling tropical development there in any of the models

[SFLcane]

Development looks very unlikely atleast anything significant at this point in the Gulf conditions are very hostile with subtropical jet coming right through there. Looks rainy next week for Florida.

[USTropics]

I mentioned there is only marginal ensemble support for development at this time (less than 50%) for good reasons. Before we get to a potential GOM track, we need to see if an actual cross over even occurs. There is some very high terrain a potential system has to cross over, and an equal chance that whatever does try to cross over gets buried in Mexico and dissipates before it can reach the GOM. A blend of the NCEP model ensembles has a 30-40% chance of development for this region.
https://i.imgur.com/hmd1nph.png

What is that big orange 50-60% area located off the coast of Venezuela/Colombia -- some kind of glitch or misclassification I'm guessing? Because I don't see anything resembling tropical development there in any of the models

That's exactly what it is, spurious vorticity due to how the algorithm handles the sigma coordinates for elevation in that area. It's a consistently false positive in that product (sometimes it's oriented further south near Panama/Columbia). Essentially in that area, due to topography (mountainous + curvature of the coastline), you get these false positive vorticity interactions:

[tolakram]

I will believe the season is winding down after the usual first cold front lull. Either we will get activity in the Caribbean in a few weeks or el nino has finally taken hold and it ends early. The Atlantic is still very warm for this time of year so there's a chance we get more unexpected activity.

[ChrisH-UK]

I mentioned there is only marginal ensemble support for development at this time (less than 50%) for good reasons. Before we get to a potential GOM track, we need to see if an actual cross over even occurs. There is some very high terrain a potential system has to cross over, and an equal chance that whatever does try to cross over gets buried in Mexico and dissipates before it can reach the GOM. A blend of the NCEP model ensembles has a 30-40% chance of development for this region.
https://i.imgur.com/hmd1nph.png

What is that big orange 50-60% area located off the coast of Venezuela/Colombia -- some kind of glitch or misclassification I'm guessing? Because I don't see anything resembling tropical development there in any of the models

That's exactly what it is, spurious vorticity due to how the algorithm handles the sigma coordinates for elevation in that area. It's a consistently false positive in that product (sometimes it's oriented further south near Panama/Columbia). Essentially in that area, due to topography (mountainous + curvature of the coastline), you get these false positive vorticity interactions:

https://i.imgur.com/jtocs4x.png

The topology of Venezuela, Colombia and Central America has a big factor in making tropical cyclones in the East Pacific. The likes of Pico Cristobal Clon which is a mountain that's 5.700m high causes a lot of the vorticity as the winds blow around it and cause turbulence in the air flow. This turbulence causes eddies which in turn causes the start of cyclones. Central America with it's volcano peaks also cause the same eddies to from and other places also have the same effect like over in the Philippines and Taiwan with its volcano's and mountains.

[La Breeze]

We'll be in along the MS Gulf Coast at the end of next week through the weekend - is there anything that we would possibly need to be watching in the Gulf at that time?

[psyclone]

We'll be in along the MS Gulf Coast at the end of next week through the weekend - is there anything that we would possibly need to be watching in the Gulf at that time?

WPC has the MS coast at the edge of some heavy rain during that time. Looks stormy of a non tropical nature.

[Ianswfl]

18z GFS ensembles sending out some signals for a strong late season Caribbean hurricane. Several runs have shown something down there now.

[CronkPSU]

06z GFS still has a storm hitting Florida at the end of its run....soooo far out still but something to kind of look at I guess in this slow period

[blp]

Looks like late October mischief on the horizon. Potential EPAC crossover.

[Ianswfl]

Looks like late October mischief on the horizon. Potential EPAC crossover.

https://i.ibb.co/hWBX4Bz/9f0c1b2159d3222c112d949e8c9cec6b096cb799e9750e63b0a2d2d643474396.png

12z gfs strengthening cat2 heading over west cuba towards the keys and fl

[Miami Storm Tracker]

Afternoon all,

Anytime I hear the Keys mentioned am like no late season isses please. If available is there any model run for this track towards the Keys.

[ronjon]

12z GFS and CMC hinting at western Caribbean low pressure development in about 10 days. Climatologically favored area. Long time to watch.

[Ianswfl]

12z GFS and CMC hinting at western Caribbean low pressure development in about 10 days. Climatologically favored area. Long time to watch.

Gotta watch timing too. That front, if it's slower or faster there is a front forecasted to clear FL. Could be problems. Waters will still be low 80s around here. Could get a Wilma type track. Even if that strong front clears, stalls down there something could form. Lots of below normal temps on the GFS for me before this tries to form so SST in the southeast Gulf will take a hit for sure here in SWFL. GFS though brings back above normal temps late in the period.

Remember, Kate has near freezing temps 10 days earlier in the Panhandle. This stretch of cooler weather late in the period isn't the end of hurricane season. it will however help keep the intensity lower if it moves into the Gulf.

[Ianswfl]

Maybe not a phantom. 18z very similar just tad faster strong cat2, weak 3 heading for tampa end of run. Ensembles running and so far those are much more active too.