2021 Global Model Runs Discussion (Out thru day 16)

[Ubuntwo]

12z GFS is more enthusiastic on the SWATL system which it has been on and off with for days. IMO that is the basin's best chance at a named storm over the next ten days. Still lacking model support outside the GFS.

Stewart just tagged it.

1. A surface trough located about 100 miles east of the southeastern
Bahamas is producing a large area of cloudiness and shower activity
along and to the east of the trough axis. Upper-level winds are
expected to be marginally conducive for slow development of this
system while it moves west-northwestward at around 10 mph through
Monday, followed by a slow northwestward motion through the end of
the week.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...20 percent.

[CyclonicFury]

Starting to see an increasing Caribbean signal on the EPS past Day 10. While the operational Euro was awful with Caribbean genesis last season, the EPS predicted the genesis of the Caribbean storms well in advance. Still a long way to go, but the timing makes sense.

[LarryWx]

All of the 12Z model runs look about as tame as one could hope for during the second climo peak with regard to their suggested CONUS TC threat levels through the end (10/18). But that's only fwiw as they're far from perfect.

[Spacecoast]

12z ECENS: 3-4 members are showing 40kt winds.... not beyond the realm of possibilities, so it bears watching.


12 GEFS Shows Bahamas area of disorganized cloudiness, (and showers). Several of these end up hitting Central Florida coast

[AlphaToOmega]

Season is definitely over, everyone knows how much 312-hour runs should be taken as gospel

[LarryWx]

Today's Happy Hour GEFS didn't act like a typically active HH GEFS. It just has a few member TCs (out of 31 members) at different intervals and is still another run that is far less threatening to the CONUS than those from a couple of days ago. So, the modeled pretty quiet relative to secondary peak climo is continuing. Let's see if this holds up and keeps the first half of the month pretty quiet for the CONUS.

Even if so, we'd still have the sometimes dangerous second half of Oct, especially in La Nina. Until we get past ~10/21, S and C FL's climo says that TC threat levels don't start decreasing. On the contrary, there have been numerous TCs in and near S FL 10/17-21. Just count up the number of TCs of past years during just that period in that vicinity and one can see how busy that period is. It may actually be the most dangerous five day interval of the season there for all I know.

[aspen]

06z GFS shows a tropical wave approaching the Lesser Antilles on Oct 11/12th and trying to develop in the eastern Caribbean on the 13/14th. This times better with the CCKW passage than the GFS’ WCar system from a few days ago, and there’s a clearer source for this one. Let’s see if it sticks over the next several runs.

[CourierPR]

06z GFS shows a tropical wave approaching the Lesser Antilles on Oct 11/12th and trying to develop in the eastern Caribbean on the 13/14th. This times better with the CCKW passage than the GFS’ WCar system from a few days ago, and there’s a clearer source for this one. Let’s see if it sticks over the next several runs.

I think this is what Met. Joe Bastardi was referring to in his Saturday Summary. He pointed to a future system in the eastern Caribbean.

[AJC3]

Folks, I just had to zap another bunch of posts here.

There's been more than the usual amount of OT sidebar cluttering up this and other threads lately, and the admin and mod staff have noted that many of the zapped posts are from the same small group of members. Please keep the seasonal indicator talk in it own thread and stick to the topic at hand in this one. Remember, there's an S2K Discord chat room you can use for the back and forth stuff that's more lenient as far as straying from topical talk.

Thank in advance.

[OuterBanker]

Folks, I just had to zap another bunch of posts here.

There's been more than the usual amount of OT sidebar cluttering up this and other threads lately, and the admin and mod staff have noted that many of the zapped posts are from the same small group of members. Please keep the seasonal indicator talk in it own thread and stick to the topic at hand in this one. Remember, there's an S2K Discord chat room you can use for the back and forth stuff that's more lenient as far as straying from topical talk.

Thank in advance.

Thank you, I was hoping one of the mods would remove them.

[wxman57]

Looking more and more like a "normal" late hurricane season, nothing like last Oct/Nov. Strong shear is already dominating the Gulf and along the East U.S. Coast. This limits potential threats to the Caribbean Sea and possibly the southern Florida Peninsula. Could be another short-lived weak system named well east of the U.S., too. Nothing on the horizon through mid October, though.

[aspen]

The CFS is now showing a WCar system forming in about a week as the Kelvin Wave passes through, and takes a Paloma ‘08/Irene ‘99 track over Cuba and OTS. The timing for this certainly makes a lot more sense than the GFS’ WCar system in the middle of a suppressive Kelvin Wave.

[cycloneye]

There has been a delay to release the 12z runs of NAM and GFS. Tropical Tidbits has this.

Oct 4: NCEP is experiencing dataflow issues causing delays in some NCEP models

[LarryWx]

12z GEFS as regards CONUS: other than hints that there MAY be a rogue TC form offshore the SE US that mills around similar to the 12Z GFS at midmonth due to being stuck underneath a strong NE US ridge, the run is still about as quiet one could hope for during this secondary climo peak all of the way to the end of the run fwiw.

[AlphaToOmega]

Ah yes, the very definition of an inactive October (please take this with a grain of salt by virtue of it being a 318-hour model run)

[LarryWx]

The 12Z EPS is about as quiet as you can have it during this often active period.

[LarryWx]

Disclaimer: this is a HH GFS run

[aspen]

This is the third GFS run in a row to show a hurricane with an Omar-like track in the NE Caribbean and central Atlantic forming in 8-10 days. It might be a real TC this time.

The GFS also really wants a Patricia or Willa repeat.

[SconnieCane]

The GFS also really wants a Patricia or Willa repeat.

That is more of an El Nino year phenomenon, though. What is with the GFS in insisting this Nina will behave more like a Nino, at least WRT tropical cyclone formation patterns?

Sent from my Pixel 4a using Tapatalk

[LarryWx]

0Z GFS suite for CONUS: another overall quiet run relative to climo other than some members having TCs skimming the E coast from time to time. It isn't too often when you see it this quiet in the W Caribbean during this 2nd peak. Is it right? Who knows? I'm just saying what the model has.