ATL: FLORENCE - Models

[SFLcane]

This..

 https://twitter.com/EdValleeWx/status/1037334503914725379

[Aric Dunn]

This..

 https://twitter.com/EdValleeWx/status/1037334503914725379

in consensus generalization ( and that is all we can ever go off of) 10 days verify all the time..

the real question is how many flip flops verify at 10 days.

[chris_fit]

Full 06Z Suite prior to the 12Z coming out. Saved Image - really all over the place.

[toad strangler]

When modeling is in upheaval always lean on climo a little heavier

Normally I'm all on board with climo but then storms like Ike, Irma, and Sandy happened and suddenly the picture became a lot more muddled.

Toms River! I from your neck of the woods ...

Climo is not always going to pan out but I'm in that camp RN. climo from current position says Florence gets picked up and lead away by the ear. We shall see! Missing that weakness and everything changes.

[Aric Dunn]

Full 06Z Suite prior to the 12Z coming out. Saved Image - really all over the place.

not really.. its usual as normal.. euro and ensembles are almost always doing the opposite of the GFS and ensmebles. the 5 day period is quite good.

[Bocadude85]

Full 06Z Suite prior to the 12Z coming out. Saved Image - really all over the place.

It seems all models show that westward bend that the UKMET shows in a few days, the UKMET just never goes back to WNW/NW like the other models show after the westward bend. It is going to be very interesting to see if the 12Z UKMET sticks to this prolonged westward movement.

[JPmia]

Can someone post the UKMET run from last night?

[otowntiger]

Full 06Z Suite prior to the 12Z coming out. Saved Image - really all over the place.

It does seem that OTS is the best bet by far. A large majority of models seem to agree. Of course climo says that too. i think as someone else said it well, a whole lot of things have to go wrong for this storm to affect CONUS.

[tolakram]

Can someone post the UKMET run from last night?

https://ruc.noaa.gov/hfip/tcgen/

Select UKM and step through the days. A couple of days are missing but the D6 and D7 graphics show the southwest and west motion.

[JaxGator]

In my humble view, despite the models, I'm quite confident that this will curve OTS, remaining E of Bermuda. It will be hard for Florence to miss the interaction between a TUTT to its east and an incoming trough to its north by days five and six. The location, large-scale troughs, and climatology would strongly favour an OTS track. Many things would need to go wrong for Florence to somehow defy all these factors, miss the trough axes, get caught under the incoming ridge, and head W toward the U.S. East Coast and/or Bermuda. Respectfully, I'm not sure as to why some people trust the UKMET/ECMWF in this situation, given their stubborn W/weak biases with Florence. While not perfect, of the global models, the GFS has performed the best in regard to the track and intensity (depth) of Florence thus far. I offer further thoughts below:

http://www.storm2k.org/phpbb2/viewtopic.php?p=2699945#p2699945

Joe B is going 1 in 4 chances of a recurve and 3 in 4 of a hit. He's got it at a "4" off the NC Coast next Wednesday. Whether he's right or not is unknown.

Yep, was watching his daily WeatherBell video brief too and noticed he was using Dora as one of his analogs for Florence. His track for Irma well before hitting the Lesser Antilles was almost spot on, except when Irma moved further north into Georgia and not coming off the coast at Savannah. This time it's different though, but either way, Joe said he would admit that he was wrong on this forecast if it didn't pan out.

Joe Bastardi

@BigJoeBastardi
Sep 4
Pattern recognition techniques are what I try to use. In a few days I may have to say, okay I was wrong , no turn back to west, but flipping with every run is not my thing, Went to west turn Saturday so will stick with it . Have several analogs but SST much warmer than those

[Aric Dunn]

No change in the 12z NAM Synoptic setup.

[OuterBanker]

Let's face it models this far put should be used for entertainment purposes only.

But, the 6z GFS is downright dangerous. That scenario would be devastating from NC to Canada (the snow in Canada is particularly interesting at the end of the run).

[TheStormExpert]

What will be key in a situation like this with Florence is...

1) How much latitude it gains prior to 60-65W.
2) How fast or slow will Florence be moving.
3) When the stall or slowdown occurs prior to the NE turn where will Florence be.

I’m leaning towards the stall and turn to the NE happening just off the Eastern U.S. between the East Coast and Bermuda. Wouldn’t be surprised to see it get dangerously close like the 06z GFS shows but I feel the Euro is too far west.

[hohnywx]

This..

 https://twitter.com/EdValleeWx/status/1037334503914725379

The day 10 prog almost certainly won’t verify. But whether or not the storm will feel the weakness will be determined in the day 4-5 window, which is much closer.

[SEASON_CANCELED]

Let's face it models this far put should be used for entertainment purposes only.

But, the 6z GFS is downright dangerous. That scenario would be devastating from NC to Canada (the snow in Canada is particularly interesting at the end of the run).

Depends on consensus.

Keep an eye on UKMET.

Was right about alot of stuff last year

[RL3AO]

We can see from Brian Tang's page that the models have consistently been too fast and too far south with Florence. That's one of the big reasons I'm not buying into an east coast threat (yet). But the model runs are always fun to watch in September so have at it.

[Mouton]

I think we should not underestimate the ridge building to the north. On its current projection, it would OTS BUT I keep coming back to the UKMet which has been persistently straight west. Path could be similar to Francis of 04 but at a high latitude IMO. Another interesting note is the ramp up to just south of cat 4 already and then a back down to cat 2.

[chris_fit]

We can see from Brian Tang's page that the models have consistently been too fast and too far south with Florence. That's one of the big reasons I'm not buying into an east coast threat (yet). But the model runs are always fun to watch in September so have at it.

[img]https://i.imgur.com/5Mz5bwt.png[/img

Good point on the bias, but question. Wouldn't slower mean greater threat to EC? Allowing storm to miss connection with the weakness and having ridge build back in? On the other hand, being further north more than forecast would bring it close to the weakness. Like a game of cat and mouse?

[RL3AO]

We can see from Brian Tang's page that the models have consistently been too fast and too far south with Florence. That's one of the big reasons I'm not buying into an east coast threat (yet). But the model runs are always fun to watch in September so have at it.

[img]https://i.imgur.com/5Mz5bwt.png[/img

Good point on the bias, but question. Wouldn't slower mean greater threat to EC? Allowing storm to miss connection with the weakness and having ridge build back in? On the other hand, being further north more than forecast would bring it close to the weakness. Like a game of cat and mouse?

Perhaps. It's all about will it being further north in the short term lead to it going out to sea or will the slower movement cause it to miss the trough? It's a balancing act where small differences are leading to huge forecast differences in the long term. The classic "unstable system" example with a marble on the top of a hill.

[Bocadude85]

What will be key in a situation like this with Florence is...

1) How much latitude it gains prior to 60-65W.
2) How fast or slow will Florence be moving.
3) When the stall or slowdown occurs prior to the NE turn where will Florence be.

I’m leaning towards the stall and turn to the NE happening just off the Eastern U.S. between the East Coast and Bermuda. Wouldn’t be surprised to see it get dangerously close like the 06z GFS shows but I feel the Euro is too far west.

I have to wonder if future model runs will show a dip to the SW? It just seems to me in cases like this where a strong high develops off the coast models initially show a stall and then westward movement, and over time that westward movement turns into a wsw to sw movement. I can think of a couple examples of this. Ike comes to mind of course, but Ike never made it north of 25N. Andrew did make it north of 25N but he was at 67-68W at that point. A strong high pressure system can do crazy things, check out the 1935 November Yankee hurricane https://en.m.wikipedia.org/wiki/1935_Yankee_hurricane of course the 1935 storm has no similarities to Florence but it does show what a strong HP system can do.