Daniel*

Merry Christmas from EPS cold backing in from NE at the end 2m temp anomaly

EPS in full out Jan 8th, MSLP anomaly something is clearly brewing moving further into January. -NAO is likely coming in early January and early indications it will be stubborn.

Cold and snow potential as soon as day 5-6 for more northern areas perhaps into Midlands as well. ECM furthest south out of all of them which is interesting from top model.

GFS 00z very much giving an entrenched cold January ages since we have seen that… vortex splitting this seems to be recurring theme now from this model, some disappointment over Xmas failed cold which always looked transitory at best, that could be very quickly forgotten about. Shenanigans happening up above, so the stakes are much higher.

A cold and wintry start to new year on GFS 00z this run tends to be the Scrooge. The culprit? The displacement of stratospheric polar vortex seems to match tropospheric pattern well.

UKMO was wintry in Scotland and far north. ECM turned pretty cold further north too below is Carlisle, conclusion the jury is out with these increasingly southerly tracking lows, interest is there especially further north. GFS continues to be the most progressive.

Similar ideas yes…

25C even using 10 year average of 2013-2022

Speak of the devil not surprised myself. I’d expect tomorrow to consolidate it even more.

Good to see geopotential heights this from ECM 12Z, wave 2 attack at the end pinching vortex. I personally think vortex is in serious trouble into early 2024 setting up for a major SSW.

Looking a bit wedgey near Iceland it’s a good area for +ve heights to form to help disrupt Atlantic lows SE 192hrs > 216hrs

A promising chart if not for Euro heights… frustrating this!

How that looks if you’re wondering… 10mb temp anomaly.

Recent runs from ECMWF has been hinting of -NAO especially yesterdays 12z, the 00z went “nope” more runs needed.

Not the first run from GFS which has hinted at blocking to NE, would be grand to set the stage nicely with a frosty high with winter sunshine. The current stalemate is intolerable.

People often rave about UKMO but that’s a substantial difference between 12z now more in line with others, Azores being a pain clearly we are not going to see major high lat blocking… whether we can get a wedge which forces the pattern south remains to be seen. Struggling to remember such a woeful period of modelling clearly a lot of complexity involved. There does seem to be growing confidence Scotland is going to be in that colder boundary leading into Xmas so a white Christmas does look to be on for some.

All eyes on in early 2024… it’s an interesting possibility which I believe is growing, with potential impacts right in the cold heart of winter. Unlike last winter and many others….

Yes a white Xmas but also cold temperatures too in Scotland... Edinburgh

The UKMO day 5 is really quite concerning thankfully I have not seen much support for a similar solution. This would be an impactful weather event a lobe of polar vortex experiencing explosive deepening to SE of Iceland and then pushing southeast down North Sea. I can’t say I’ve ever seen a strong storm take that NW>SE trajectory. I suppose it is possible otherwise it wouldn’t be shown!

UKMO gone full pelt… strong pressure drop south into central Europe, unusually strong NW winds with Arctic air being fed in, the next few days would likely offer wintriness quite widely. A white Xmas could well land this year…..

Interesting development in GFS ens quite a tight colder clustering from Christmas Eve mean dropping to -4C at 850hPa in London and -5C by Christmas Day.

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 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...

A set up like this would totally bury the higher ground of north, blizzards even with very large drifts. Relocating trop vortex being very influential on pattern.

The pressure difference in eastern Canada is huge. This run is even more amplified there than 18z. I think it could be a decent run… Latest t180

Pretty clear OP was somewhat of an outlier with ridging into Europe at day 10. Appears trop vortex is going to migrate eastwards to Scandinavia which is in line with GFS. EPS