2020 Global Model Runs Discussion (Out thru day 16)

[northjaxpro]

https://twitter.com/osuwxguy/status/1302673436435795979?

This! I agree with this tweet, and like I stated yesterday, i would put money on seeing substantial changes in the pattern and model runs within the next several days.

[TheStormExpert]

https://twitter.com/osuwxguy/status/1302673436435795979?

This! I agree with this tweet, and like I stated yesterday, i would put money on seeing substantial changes in the pattern and model runs within the next several days.

Even if we do see changes the 500mb steering pattern seems very progressive.

[northjaxpro]

https://twitter.com/osuwxguy/status/1302673436435795979?

This! I agree with this tweet, and like I stated yesterday, i would put money on seeing substantial changes in the pattern and model runs within the next several days.

Even if we do see changes the 500mb steering pattern seems very progressive.

The pattern will be gradually evolving over a period of about a week from now. We all don't know to the magnitude of the 500 mb ridging yet until next week.But, like I said yesterday, it is a very tough proposition to go against the teleconnection forecast of a strong + NAO index and what it is projecting during the next two weeks.

[LarryWx]

12Z UKMET for TW expected to emerge off Africa ~9/10:

- It comes off at quite a low latitude (way down at 11N): Is that realistic when considering model consensus?
- It has it move at this low latitude WNW at an average speed of a whopping 18 mph, which is lightning speed compared to what it has for 92L and 93L
- It has it dropping to 980 mb, which is already bordering on cat 2 H strength while still way out at 30W

So, IF all of this is pretty accurate, this may be the most dangerous of 92L, 93L, and this one by far mainly because of added uncertainty from it being further into the future although it, of course, may still recurve way OTS:


NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 90 HOURS
FORECAST POSITION AT T+ 90 : 11.2N 16.1W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 10.09.2020 96 11.1N 17.9W 1002 34
0000UTC 11.09.2020 108 11.3N 20.6W 995 49
1200UTC 11.09.2020 120 11.9N 23.4W 991 46
0000UTC 12.09.2020 132 12.9N 26.5W 987 50
1200UTC 12.09.2020 144 13.9N 30.3W 980 57

[Spacecoast]

12Z UKMET for TW expected to emerge off Africa ~9/10:


So, IF all of this is pretty accurate, this may be the most dangerous of 92L, 93L, and this one by far:

12z GEFS is rapidly losing enthusiasm for this 9/10 wave:

[TheStormExpert]

12Z UKMET for TW expected to emerge off Africa ~9/10:

- It comes off at quite a low latitude (way down at 11N): Is that realistic when considering model consensus?
- It has it move at this low latitude WNW at an average speed of a whopping 18 mph, which is lightning speed compared to what it has for 92L and 93L
- It has it dropping to 980 mb, which is already bordering on cat 2 H strength why out at 30W

So, IF all of this is pretty accurate, this may be the most dangerous of 92L, 93L, and this one by far mainly because of added uncertainty from it being further into the future although it, of course, may still recurve way OTS:


NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 90 HOURS
FORECAST POSITION AT T+ 90 : 11.2N 16.1W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 10.09.2020 96 11.1N 17.9W 1002 34
0000UTC 11.09.2020 108 11.3N 20.6W 995 49
1200UTC 11.09.2020 120 11.9N 23.4W 991 46
0000UTC 12.09.2020 132 12.9N 26.5W 987 50
1200UTC 12.09.2020 144 13.9N 30.3W 980 57

So why would this next wave behind 92L and 93L move at lightning speed compared to our current two invests?

[USTropics]

12Z UKMET for TW expected to emerge off Africa ~9/10:

- It comes off at quite a low latitude (way down at 11N): Is that realistic when considering model consensus?
- It has it move at this low latitude WNW at an average speed of a whopping 18 mph, which is lightning speed compared to what it has for 92L and 93L
- It has it dropping to 980 mb, which is already bordering on cat 2 H strength why out at 30W

So, IF all of this is pretty accurate, this may be the most dangerous of 92L, 93L, and this one by far mainly because of added uncertainty from it being further into the future although it, of course, may still recurve way OTS:


NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 90 HOURS
FORECAST POSITION AT T+ 90 : 11.2N 16.1W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 10.09.2020 96 11.1N 17.9W 1002 34
0000UTC 11.09.2020 108 11.3N 20.6W 995 49
1200UTC 11.09.2020 120 11.9N 23.4W 991 46
0000UTC 12.09.2020 132 12.9N 26.5W 987 50
1200UTC 12.09.2020 144 13.9N 30.3W 980 57

So why would this next wave behind 92L and 93L move at lightning speed compared to our current two invests?

High pressure builds back in over NW Africa and accelerates the low-level flow:


End of the UKMET run:

[LarryWx]

12Z UKMET for TW expected to emerge off Africa ~9/10:

- It comes off at quite a low latitude (way down at 11N): Is that realistic when considering model consensus?
- It has it move at this low latitude WNW at an average speed of a whopping 18 mph, which is lightning speed compared to what it has for 92L and 93L
- It has it dropping to 980 mb, which is already bordering on cat 2 H strength why out at 30W

So, IF all of this is pretty accurate, this may be the most dangerous of 92L, 93L, and this one by far mainly because of added uncertainty from it being further into the future although it, of course, may still recurve way OTS:


NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 90 HOURS
FORECAST POSITION AT T+ 90 : 11.2N 16.1W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 10.09.2020 96 11.1N 17.9W 1002 34
0000UTC 11.09.2020 108 11.3N 20.6W 995 49
1200UTC 11.09.2020 120 11.9N 23.4W 991 46
0000UTC 12.09.2020 132 12.9N 26.5W 987 50
1200UTC 12.09.2020 144 13.9N 30.3W 980 57

So why would this next wave behind 92L and 93L move at lightning speed compared to our current two invests?

High pressure builds back in over NW Africa and accelerates the low-level flow:
https://i.imgur.com/3mhtmpa.png

End of the UKMET run:
https://i.imgur.com/mkNJY0C.png

Thanks for posting that. Is that trough to the west, which at 144 hours is scooping up 92L and also helping to then recurve 93L, suggesting recurve later for this one within a couple of days? Or is there going to be high pressure building in behind those two as they are already then moving pretty much N. Opinion?

[aspen]

Here are all of the disturbances the models are currently showing with at least the potential to develop.

—92L, likely to become Paulette within 48 hours

—93L, likely to become Rene in 48-72 hours

—Low pressure area SE of Bermuda, ICON shows development near SEUS cost

—Third tropical wave expected to emerge into the Atlantic in 4 days, could quickly gain organization like 93L

—Possible GoM disturbance in 9-10 days, CMC and GFS-Para have been on-and-off with development

92L, 93L, and the third AEW all have nearly unanimous model support for development. The Bermuda AOI has only been developed by the ICON, and the GoM disturbance only has some models showing anything at all. At this point, the most likely scenario for the next week is Paulette, Rene, and Sally forming in the MDR.

[SFLcane]

12Z UKMET for TW expected to emerge off Africa ~9/10:

- It comes off at quite a low latitude (way down at 11N): Is that realistic when considering model consensus?
- It has it move at this low latitude WNW at an average speed of a whopping 18 mph, which is lightning speed compared to what it has for 92L and 93L
- It has it dropping to 980 mb, which is already bordering on cat 2 H strength while still way out at 30W

So, IF all of this is pretty accurate, this may be the most dangerous of 92L, 93L, and this one by far mainly because of added uncertainty from it being further into the future although it, of course, may still recurve way OTS:


NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 90 HOURS
FORECAST POSITION AT T+ 90 : 11.2N 16.1W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 10.09.2020 96 11.1N 17.9W 1002 34
0000UTC 11.09.2020 108 11.3N 20.6W 995 49
1200UTC 11.09.2020 120 11.9N 23.4W 991 46
0000UTC 12.09.2020 132 12.9N 26.5W 987 50
1200UTC 12.09.2020 144 13.9N 30.3W 980 57

Interesting... but still see a huge weakness in between ridges.

[sma10]

This! I agree with this tweet, and like I stated yesterday, i would put money on seeing substantial changes in the pattern and model runs within the next several days.

Even if we do see changes the 500mb steering pattern seems very progressive.

The pattern will be gradually evolving over a period of about a week from now. We all don't know to the magnitude of the 500 mb ridging yet until next week.But, like I said yesterday, it is a very tough proposition to go against the teleconnection forecast of a strong + NAO index and what it is projecting during the next two weeks.

I have to agree that model changes are still coming. Over the next 5 days it appears that 92 and 93 will develop to some extent and continue generally westward, but afterwards things too chaotic imo. The latest 18z GFS has three systems literally criss crossing each other like ducks in a shooting gallery. Anytime I've seen this type of weirdness in the past, the eventual solution always was something unexpected... so I figure we'll just have to sit back and wait to see what actually happens days 6+

[Aric Dunn]

Sure... ill ask again.. how is the model consensus going for everyone ? lol

I think the GFS is showing not only a +NAO and -NAO.. but an Imaginary NAO lol

[sma10]

Sure... ill ask again.. how is the model consensus going for everyone ? lol

I think the GFS is showing not only a +NAO and -NAO.. but an Imaginary NAO lol

https://i.ibb.co/pZ3YyDw/gfs-z850-vort-atl-fh0-336.gif

Notated thusly: NAOi

[AnnularCane]

Sure... ill ask again.. how is the model consensus going for everyone ? lol

I think the GFS is showing not only a +NAO and -NAO.. but an Imaginary NAO lol

https://i.ibb.co/pZ3YyDw/gfs-z850-vort-atl-fh0-336.gif

Darn, now I'm really hoping this happens but it probably won't.

[LarryWx]

Here we go with still another curve ball or even knuckleball in this case: check out the members on the map below of the Happy Hour GEFS with TCs, some Hs, in the E Caribbean and just E. These are from those members which come off Africa at a low latitude on Sept 10th. That supposed Sep 10th wave is making me dizzy from all of the twists and turns. Remember a couple of days ago when the Euro was barreling westward east of the LAs and the EPS had a pretty threatening run?



Then 4 of these (20%) of all of the 21 members hit the CONUS E coast bigly;

[SFLcane]

Here we go with still another curve ball or even knuckleball in this case: check out the members on the map below with TCs, some Hs, in the E Caribbean and just E. These are from those members which come off Africa at a low latitude on Sept 10th. That supposed Sep 10th wave is making me dizzy from all of the twists and turns. Remember a couple of days ago when the Euro was barreling westward east of the LAs and the EPS had a pretty threatening run?

https://i.imgur.com/w0iwTsm.png

Hi Larry,

Yep sure remember that but sense then eps has abandoned that idea atleast for now. Not sure I understand you.

[TheStormExpert]

This! I agree with this tweet, and like I stated yesterday, i would put money on seeing substantial changes in the pattern and model runs within the next several days.

Even if we do see changes the 500mb steering pattern seems very progressive.

The pattern will be gradually evolving over a period of about a week from now. We all don't know to the magnitude of the 500 mb ridging yet until next week.But, like I said yesterday, it is a very tough proposition to go against the teleconnection forecast of a strong + NAO index and what it is projecting during the next two weeks.

I’d agree more but currently the Bermuda High is non-existent. That’s what helps steer storms further west towards the U.S. and Florida. Here’s a tidbit from this afternoon’s NWS: Miami discussion.

The pattern starts off with the lack of a Bermuda high and a
broad, weak 500mb low over the area.

[USTropics]

Here is an example of the GFS bias in over-doing troughs, and this is just a 3-5 day forecast trend (500mb height anomalies):


This a known bias in both the current GFS and still the GFS-para (with slight improvements):


Those cold temps getting all the way to the GOM? Looking less likely now. Here is the GFS 5-7 day trend again:


5 day forecast on the 12z ECMWF run:


Here is a view of the 5-7 day forecast trend by the GFS (500mb height anomalies):


Operational models are all over the place. Just for fun, here is the 10-12 day trend of the GFS:


How this all plays out? No idea, and I don't believe anyone can say with much confidence what will happen 5+ days out. As stated last week by some of us on here, model verification scores were going to take a hit due to the amplified pattern change (partly attributed to two consecutive recurving typhoons). I think odds still favor some recurving systems, but it's definitely not set in stone. If these troughs aren't as deep (and we've seen the models are having issues already with this), they could just as easily scoot over the top and amplify ridging. For now we'll have to see what actually forms (and becomes the dominant system if multiple systems form) and how the models continue to adjust to the 500mb pattern. The ensembles provide the best tool for that.

[Hurricaneman]

Here we go with still another curve ball or even knuckleball in this case: check out the members on the map below with TCs, some Hs, in the E Caribbean and just E. These are from those members which come off Africa at a low latitude on Sept 10th. That supposed Sep 10th wave is making me dizzy from all of the twists and turns. Remember a couple of days ago when the Euro was barreling westward east of the LAs and the EPS had a pretty threatening run?

https://i.imgur.com/w0iwTsm.png

Wouldn’t be surprised if the OP models have the first 2 systems head out to sea with the 90/90 near Bermuda with the 70/90 to its East but the one over Africa coming off on the 10th might end up being a threat as the ridge rebuilds but I could be wrong and this follows the others as fish but it seems the model ensembles are trending west with the feature over Africa

[cycloneye]

NHC highlighted the wave that will emerge Africa by midweek and global models like UKMET, GFS and ECMWF develop. Posts related to model runs for that wave in particular are now going to be posted at the wave thread.

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