Model Output Discussion - Into Winter

[Snowman.]

1 GEFS suite, but a jump from Westerly mean to NW'ly mean.

 

 

 

 

Edited December 13, 2023 by Snowman.

[Allseasons-Si]

We are starting to ferm up on a PM blast now,...how long that will last is writing another book tomorrow

us coldies will hope that future upgrades will turn up just in time for the big day with some wintry surprises

it would be good to see snow falling on the big day wouldn't it?

still some way to go though in terms of model watching and the placement of this trough for a direct hit on the UK

great buzz in here tonight though it has to be said.

GN peeps

 

Edited December 13, 2023 by Allseasons-Si

[Ladyofthestorm]

Just checked the ensembles for Aberdeenshire, it's looking pretty much nailed on a return of colder weather from middle of next week 

Even the even the ECM is agreeing.

Looks like a NW and wild with it. Could see gales, travel disruption just before Christmas. 

[Daniel*]

27 minutes ago, Ladyofthestorm said:

Is it just me, but does nearly every chart on any weather model showing the 500 pa seem to have the polar vortex very stretched and elongated.

 

This is an el nino winter afterall. It should be wound up tightly over the pole. 

Wrong. El Niño winters have a higher frequency of major SSWs than La Niña winters, the addition of eQBO as we have this winter as seen in 2009 is one of most compelling pointers towards an increased likelihood of major disruption to SPV. 

“The El Niño–Southern Oscillation (ENSO) can impact the Northern Hemisphere wintertime stratospheric variability, and the prevalence of sudden stratospheric warmings (SSWs). Understanding the ENSO–SSW link can help interpret seasonal model predictions and improve seasonal forecasts. The increased convection in the tropical east Pacific during an El Niño event triggers a Rossby wave train that strengthens and deepens the Aleutian low (Bell et al., 2009; Cagnazzo and Manzini, 2009). This leads to constructive linear interference of the planetary waves and an increased wave flux into the stratosphere and hence a weakened stratospheric polar vortex. During El Niño years the polar vortex is, on average, weaker than in neutral years, and El Niño is also associated with an increase in the number of SSWs (Domeisen et al., 2019).

Although La Niña is the opposite phase to El Niño, the negative SST anomalies tend to be weaker, more westward, and have a different time evolution (Hoerling et al., 1997; Larkin and Harrison, 2002; Frauen et al., 2014). The decrease in convection in the topical east Pacific associated with La Niña still leads to a shallower Aleutian low, decreased wave flux, and a stronger polar vortex (Iza et al., 2016; Jiménez-Esteve and Domeisen, 2019; Domeisen et al., 2019).”

Sudden stratospheric warmings during El Niño and La Niña: sensitivity to atmospheric model biases

WCD.COPERNICUS.ORG

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Abstract. The number of sudden stratospheric warmings (SSWs) per year is affected by the phase of the El Niño–Southern Oscillation (ENSO), yet there are discrepancies between the observed and...

 

Edited December 13, 2023 by Daniel*

[Gadje]

38 minutes ago, Spah1 said:

You don’t wait to see how your football team did at the end of the season you enjoy the highs and lows of each game and the hope and despair. 

That explains a lot its footie fans discussing the weather on here.

[Beanz]

1 hour ago, Tim Bland said:

Boxing Day snow for some …

A 306h precip chart…useless 

Edited December 14, 2023 by Beanz

[Cheshire Freeze]

Here it comes

[Ali1977]

2 minutes ago, Cheshire Freeze said:

Here it comes

Mental blizzards for some 

[Cheshire Freeze]

Well that’d certainly be a red wind warning, probably the largest ever issued

[Ali1977]

Just now, Cheshire Freeze said:

Well that’d certainly be a red wind warning, probably the largest ever issued

With heavy snow too

[Cheshire Freeze]

Just now, Ali1977 said:

With heavy snow too

Off the scale jet streak

[Cheshire Freeze]

This GFS run is actually insane. Some really severe weather showing on it. Completely destructive at D8.

[Ali1977]

Just now, Cheshire Freeze said:

This GFS run is actually insane. Some really severe weather showing on it. Completely destructive at D8.

Cold, snow, blizzards, stormy - I’m more excited about this that a cold dry easterly ️ The GEM is good too. Let’s see where the GFS leads us at Xmas day!! 

[feb1991blizzard]

8 minutes ago, Cheshire Freeze said:

Well that’d certainly be a red wind warning, probably the largest ever issued

yes - people thinking just about snow - wind could be severe - ecm showed this a fw days back

[Cheshire Freeze]

Just now, feb1991blizzard said:

yes - people thinking just about snow - wind could be severe - ecm showed this a fw days back

Widespread power outages if the 0z GFS came to fruition. 100mph gusts around coasts and even more crazy, 80mph gusts well inland.

[feb1991blizzard]

Just now, Cheshire Freeze said:

Widespread power outages if the 0z GFS came to fruition. 100mph gusts around coasts and even more crazy, 80mph gusts well inland.

tamara eluded to the threat of severe weather possibilities for Europe - with jet patterns like that she could be right.

[Ali1977]

528 cleared the U.K., cold dew points, severe wind chill - charts for the end of next week off this run - just one run but pretty mad!! 
Oh and 100 mph winds from Greenland 

[Daniel]

Concerning gfs this morning in terms of wind speeds blizzards up north aswell 

[Cheshire Freeze]

3 minutes ago, Ali1977 said:

528 cleared the U.K., cold dew points, severe wind chill - charts for the end of next week off this run - just one run but pretty mad!! 
Oh and 100 mph winds from Greenland 

And a strat that looks like it wants to chuck in the towel

 

[Cheshire Freeze]

Looking at how things are coming together, I really wouldn’t be surprised if we see the coldest January in a decade.

The ingredients are certainly there for all to see. I’m pretty sure at this point that somewhere in N Europe is going to cop a severe wintry outbreak…let’s hope it’s the UK for a change.

[Battleground Snow]

Ukmo and gfs not that dissimilar at 168 either.

High impact weather chances are increasing for sure.

[feb1991blizzard]

8 minutes ago, Cheshire Freeze said:

Looking at how things are coming together, I really wouldn’t be surprised if we see the coldest January in a decade.

The ingredients are certainly there for all to see. I’m pretty sure at this point that somewhere in N Europe is going to cop a severe wintry outbreak…let’s hope it’s the UK for a change.

last severely cold one was 87, 0.8, very mild beginning, mild end, still took an age for snow to all melt though, some spell that was.

Edited December 14, 2023 by feb1991blizzard

[Cheshire Freeze]

5 minutes ago, feb1991blizzard said:

last severely cold one was 87, 0.8, very mild beginning, mild end, still took an age for snow to all melt though, some spell that was.

Looks like a mild US/Canadian winter to me at this point. The location of the strat PV towards Europe looks like it has longevity with repeated warmings working their way around to the Canadian side.

The upshot would, to me, be a predisposition to deep troughing across and down through the European sector…aided and abetted at times by the tpv dropping through Scandi. In previous years we’ve seen this across the US with deep cold being propelled south. Looks like it’s our turn this year…

The outlook looks cold to me.

Edited December 14, 2023 by Cheshire Freeze

[northwestsnow]

Colder air further south next saturday compared to the 18z mean below

 

UPGRADE 

 

[Cheshire Freeze]

4 minutes ago, northwestsnow said:

Colder air further south next saturday compared to the 18z mean below

 

UPGRADE