2018 Tropics: Global Model Runs Discussion (Out to day 16)

[Hurricaneman]

My feeling is that either the models are trash or there is just not going to be any forcing to get any tropical systems but some very historic storms didn’t show up on models until within 5 and sometimes 3 days so any solution beyond 5 days tends to be off, look at Harvey, Joaquin, Danny, Beryl, and Maria as examples of this so if you see nothing beyond 5 days on the models it may be because and this is just an opinion that models tend to look at the current background state through the run instead of looking at changing conditions later on

[Hypercane_Kyle]

My feeling is that either the models are trash or there is just not going to be any forcing to get any tropical systems but some very historic storms didn’t show up on models until within 5 and sometimes 3 days so any solution beyond 5 days tends to be off, look at Harvey, Joaquin, Danny, Beryl, and Maria as examples of this so if you see nothing beyond 5 days on the models it may be because and this is just an opinion that models tend to look at the current background state through the run instead of looking at changing conditions later on

Looking like destructive windshear across most of the Atlantic basin is what keeps the storms from developing on the GFS at least.

[Hurricaneman]

12z Euro is a Uber yawn fest

Not exactly, I see 3 potential systems with one approaching the Carolinas

[toad strangler]

12z Euro is a Uber yawn fest

Not exactly, I see 3 potential systems with one approaching the Carolinas

Weak waves in poor environments. YAWN

[Shell Mound]

The time frame for U.S. threats may also be limited to the first half of September, Pacific forcing favouring East-Coast troughs late in the month:
 https://twitter.com/webberweather/status/1033341354070495232



After late September, developing El Niño and ongoing, increasing shear over the Caribbean and Gulf may shut down late-season homegrown TCs.

Note: this is not directly related to model runs but is something to keep in mind when looking at future model trends.

[Hurricaneman]

One thing I also noticed is that when the GFS hits truncation after 10 days the systems weaken or disappear due to lower resolution which means there could be systems that can’t be resolved so when GFS goes after 240hrs it becomes fantasyland

[toad strangler]

One thing I also noticed is that when the GFS hits truncation after 10 days the systems weaken or disappear due to lower resolution which means there could be systems that can’t be resolved so when GFS goes after 240hrs it becomes fantasyland

lol the GFS is fantasy at 120 let alone 240

[CyclonicFury]

Some GEFS ensemble members are picking up on some weak TC development near Cabo Verde next Saturday.

[Hammy]

168H Euro showing a low-latitude tropical low for the first time in any of the runs, the rest have been around 15-20N.

[bamajammer4eva]

I think the models are trying to produce something but no cigar so they just drop it the very next run. 2018 may be so unfavorable that we don't even have a peak of the season for the Atlantic this year. Notice how sharply seasonal forecasts have come down. I think looking to Africa is a waste of time and we should just be aware of homegrown activity. Just my opinion

[GCANE]

Sunday 06Z GFS
Spins up a ITCZ surface low 174 hrs out.
Keeps it going thru the islands to PR.

[Blown Away]

Basically nothing up to September 10th...

[toad strangler]

 https://twitter.com/BenNollWeather/status/1033678930689941506

[Steve]

06Z GFS hits South Texas with a weak tropical low at 222 hours (valid 12z 9/4/18) which travels pretty far west into Texas near the RGV as it pushes WNW through the state.

[cycloneye]

GFS hits South Texas with a weak tropical low at 222 hours (valid 12z 9/4/18) which travels pretty far west into Texas near the RGV as it pushes WNW through the state.

That is from Wave in Atlantic.I posted the run in that thread.

viewtopic.php?f=31&t=119772&p=2694061#p2694061

[Hurricaneman]

12zgfs shows little to nothing going on

[SoupBone]

12zgfs shows little to nothing going on

Instead of windshield wiper models, we have complete flip flops right now. One run showing 3 waves, hen nothing, then 3 waves, then nothing.

Still, it's peak season, somewhere in the Atlantic, something will give and they'll be something to track. I just hope it isn't that one wave heading toward the Caribbean.

[crownweather]

12zgfs shows little to nothing going on

The inconsistency of the GFS model between runs has been something else. Given that, I'm pretty skeptical of its output. Literally, the GFS has gone from a nothing burger to a tropical cyclone fest and then back to a nothing burger in just 4 runs.

[stormlover2013]

One thing it has been consistent on is that stout ridge!!! Gom could get busy

[gatorcane]

The global models are starting to latch onto a wave over West Africa that will make the plunge in 3-4 days. For example the FV3 GFS has a Tropical Storm impacting the Cape Verde islands day 5:



It strengthens (yes strengthens in the MDR) through day 7:



12Z GEFS: