Model output discussion 24/01/21

[MJB]

 

6z ENS

 

Edited January 25, 2021 by MJB

[sheikhy]

Gfs 06z westerly across england at 72 hours!!ecm 06z southeasterly winds at 72 for england!!might not seem much but could make a huge difference at ground level!!?

[Man With Beard]

14 minutes ago, sheikhy said:

Gfs 06z westerly across england at 72 hours!!ecm 06z southeasterly winds at 72 for england!!might not seem much but could make a huge difference at ground level!!?

We often talk about FI being early in runs, but I can't remember it ever being earlier. A situation where fronts push with a negative tilt from the SW is always prone to error, and we have 3 of them coming up in row this week. 

GEFS ensembles at T120: 

Meteociel - Panel GEFS

WWW.METEOCIEL.FR

 

pretty similar to ECM ensembles at the same time. There's going to be some forecasting chaos for this coming Saturday as a low pressure tries to go rogue and slip under the main troughs to the north. How this works out is very messy. A lot of ensembles, particularly on the ECM, have a snow event for Saturday of potentially larger proportions than yesterday, but where this event will be is currently a scatter gun approach, or it may miss to the south entirely as the ECM op does. However, not impossible there'll be snow events in wider areas across the north in coming days if incoming fronts stall against the slight ridge in front.

[Battleground Snow]

MJO update, not a great one today.

 looks like the other factors some have alluded to are starting to play out, more time in phase 6, which is going to add to the "always day 10 charts" and "solar input increasing" calls.

The GEFS in particular are showing a strong push on amplitude into 7, but this is over a week away.

Nothing scientific and just a hunch, but it's starting to feel like we may have another late Feb early March winter special on the cards.

Still some snow chances in the next 7 days as @Man Without Beard has highlighted, but slim chances of deeper cold.

[phil nw.]

Until the mist clears for the weekend it's always worth looking short term at the UKMO raw and fax charts.

First the fax shows at t84 that the Atlantic fronts do stall around the borders and the cold remains to the north on the raw T96

and by day 5 the cold air is filtering back south.

As we approach the end of the week with cold air back and another Atlantic low expected we could well see another snow event where the boundary ends up and that is the mist to be cleared.

[MJB]

This is a good read

MJO Forecast and Stratospheric Warming: Impact of Extremes - World Climate Service

WORLDCLIMATESERVICE.COM

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Summary: Historical analogs point to the likely impacts of a weak stratospheric polar vortex and an amplified MJO forecast

Apologies if its already been posted 

[Paul]

For those who have been wondering about the 500mb anomaly charts, how to read them and how useful they are, here's a guide from John:

 

[sheikhy]

18 minutes ago, phil nw. said:

Until the mist clears for the weekend it's always worth looking short term at the UKMO raw and fax charts.

First the fax shows at t84 that the Atlantic fronts do stall around the borders and the cold remains to the north on the raw T96

and by day 5 the cold air is filtering back south.

As we approach the end of the week with cold air back and another Atlantic low expected we could well see another snow event where the boundary ends up and that is the mist to be cleared.

Ecm looks further south on the 06z run!!!!

[turkishfella]

Promising February perhaps?

10-15 day Weather: A strong MJO wave will face the North Hemispheric circulation, causing interference in the weather patterns as we head into February

WWW.SEVERE-WEATHER.EU

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The United States and Europe will feel the weather influence of the emerging MJO wave, interfering with the February weather development

[offerman]

2 hours ago, MJB said:

Shows yesterdays snow cover , quite an area 

Hi MJB where did you get the brilliant  snow cover satellite pic from ? 

 

Thanks

[phil nw.]

3 minutes ago, sheikhy said:

Ecm looks further south on the 06z run!!!!

Yep and if you check the t84 fax with the previous t96 a slight shift south has been made on those fronts.

Little changes in this marginal setup can make a difference to where any boundary sits later on.

[fromey]

Just read that the PV has split again.

major vortex is over Siberia and a minor daughter vortex is north of Chicago.

could we see more model flips and flops 

will there be any impact from this.?

anyone want to take a stab at it!

[Battleground Snow]

Icon with a minor adjustment Thursday @sheikhy.  The way the models adjusted the snow at just 24 hours yesterday, I wouldn't rule out more adjustments at that range.

 

[Day 10]

Pattern a little further south here in the ICON, slightly better heights up toward Iceland.

[Day 10]

Much better, cold coming back south only at 96, still plenty of changes to come near term by looks of things.

 

[Battleground Snow]

Huge difference later on at 108.... Into an Easterly 

This will excite @nick sussex

Edited January 25, 2021 by Battleground Snow

[sheikhy]

2 minutes ago, Battleground Snow said:

Huge difference later on at 108.... Into an Easterly 

This will excite @nick sussex

The most important thing is its moved towards ecm early on!cant rule out battleground snowfall for northern and eastern aread on thursday especially if ecm continues to trend further south and west!!

[northwestsnow]

Icon blowing up lows now . .

138 looks like another low waiting in the wings.

[nick sussex]

7 minutes ago, Battleground Snow said:

Huge difference later on at 108.... Into an Easterly 

This will excite @nick sussex

An easterly is going to be a hard slog but it’s important to get some cold air west in case the upstream low disrupts so that’s in place for some frontal snow. 

Certainly a bit more encouraging in the earlier timeframe which is good to see.

[sheikhy]

For me this is it!!!if its gona happen then the models gota change now!!!!forget the snowfall end of feb early march where theres a high chance of it melting with the sun higher up in the sky!!!it has to happen now we can still make the most of this between now and mid feb but we have to see a change now!!

[northwestsnow]

Icon is awful.

Next...

[Battleground Snow]

2 minutes ago, nick sussex said:

An easterly is going to be a hard slog but it’s important to get some cold air west in case the upstream low disrupts so that’s in place for some frontal snow. 

Certainly a bit more encouraging in the earlier timeframe which is good to see.

Yes, it was very brief haha, still would rather have better synoptics in the reliable than FI

[MJB]

11 minutes ago, northwestsnow said:

Icon is awful.

Next...

You need to explain why , saying that helps no one 

[Drifter]

14 minutes ago, northwestsnow said:

Icon is awful.

Next...

Only in FI which is at 120hrs onwards currently. 

Edited January 25, 2021 by Drifter

[sheikhy]

Early changes on gfs 12z!!atlantic slightly further west and moved towards ecm!!not sure if it wil make a difference!