SqueakheartLW

Some more decent cold charts appearing in the GFS, GEM and ECM. Unfortunately all of them are over 300 hours away GFS 18z P03 How about a nice late November Arctic blast to get us started. Would happily take this early start to winter if it turns out to be the teaser for the overall winter pattern. GFS 18z P14 A nice cold continental feed here would do nicely, especially as it looks like it could be a snow maker with the approaching Atlantic trough. GFS 00z P14 My favourite of all of the GFS cold options on offer in this selection. A nice early season beasterly here. GFS 06z P18 Not as good as the opening Arctic northerly but I'd still take this over the usual mild dross we see these days. GFS 12z P16 A nice cold and frosty option if we can't have one of the more snowy ones above. GFS 12z P26 Another variation on the cold and frosty theme if we don't get the first one. GEM 12z P20 GEM only had 1 decent option between the 00z and the 12z and this is it and at least it looks to be quite a decent offering at least with a cold and possibly snowy northerly on offer. ECM 12z P18 ECM has this northerly on offer to open up and is quite similar to the GEM option above. Are we seeing a common theme here. Is this how November is going to end I wonder. ECM 12z P22 The much better northerly option of the 2 ECM ones in that it looks more of a set in stone block compared with the first option. I'd take this one to get winter off to a proper start. ECM 12z P49 ECM's version of cold and frosty here. As this is more or less at the end of the run will this pattern evolve into northern blocking and an extension of the cold or will the usual typical thing happen and the polar vortex will win and turn things mild?

January and February as you say are better for getting cold outbreaks but February isn't always so good in the snowmelt department as the sun is getting a bit too strong. If you can get decent cold in December I find that better than February with the much weaker sun meaning snow sticks around like in December 2010 for example.

CFS which stands for Can't Forecast Snow is showing on it's 4 most recent 1 monthly runs that there's quite a good chance of cold on this day with a snow chance quite possible 00z 00z shows a nice easterly flow but the uppers aren't anything special so a bit of a question mark here but maybe things could firm up a bit more or the cold could upgrade before then. 06z 06z here shows another easterly so we are at 50% chance of an easterly on this day already but snow chances here probably almost zero as it looks like a dry easterly. Maybe some frost and ice for you here to cancel the day. 12z 12z is the zonal option here of the 4 we have so if you need an excuse to get out of it then you could day it's raining too much or you could claim that you have been flooded and can't come. 18z 18z is probably the option you would want to bank on to cancel this trip. It looks the snowiest of the 4 options available.

Here's the coldest charts from each of today's 12z runs from GFS, GEM and ECM to get us warmed up nicely or should I really say cooled down ready for winter 2023/24 with some late November cold shots. GFS 12z P15 GEM 12z P05 ECM 12z P19 Take your pick, a nice Scandi high and an easterly, A Greeny/Iceland high with a northerly or a close to UK high with a cold NE wind.

I most certainly hope this doesn't come to pass Dec 1868 = 7.2C Jan 1869 = 5.6C Feb 1869 = 7.5C Winter 1868/69 = 6.77C Dec 2023 = 8.6C Jan 2024 = 8.0C Feb 2024 = 5.1C Winter 2023/24 = 7.23C What could be worse than totally smashing the mildest winter on the CET record by a big margin

I'd like to see what you have to say next spring once we've passed winter. Perhaps you may supply us all with the winning lottery numbers for next week LOL

Do I see that dreaded word DOWNGRADE there?

Any Novembers with snow events or early tastes of winter within them so as follows: 1993 1996 2001 2005 2010 2017

In theory it should be better for our snow chances if we get those warm anomalies away from NINO 1+2 and to a lesser extent NINO 3 as well but knowing how things are for us in the UK these days any kind of ENSO won't make a blind bit of difference anymore.

That was the same streamer that overnight 30th November into 1st December 2010 gave me 16 inches of snow, the deepest fall I have seen in my entire life and this snow including any melting took until 2nd week of January 2011 before the last traces of this finally melted.

It would just be our typical rotten luck in the UK that we are in the middle of the biggest -50% or more region in the entire world

In other words an average winter expected

It is known that -AO and especially -NAO just before and during the SSW is a bad setup to have. The SSW will very likely flip the pattern to +AO and +NAO if this happens. The opposite is also true in many cases too.

Volcanic eruptions found to dampen Indian Ocean El Niño events for up to 8 years PHYS.ORG Volcanic eruptions occurring in tropical regions (23°N/S of the equator) have been linked to abrupt disruption of global-scale climate cycles in the Indian Ocean over the last 1 million years in... Here's a good read for you all. Consider this one in regards to that big volcanic eruption we saw in the tropical Pacific last year.

I'd rather have a strong PV in the autumn as most years see it weaken in the winter if this happens. When we've had a weak PV in the autumn it seems to have a habit of suddenly going to PV of doom status once winter arrives.

We may even have time for a decent warming early December that slows the vortex right down but a reversal might not be a likely outcome this early but then could pave the way for a major warming in January or February that destroys the vortex. Maybe there is still some hope for this winter after all and the payback for both El Nino and EQBO in combination could deliver once again like it has done so many times in the past. My analysis in the ENSO thread a few weeks back did show El Nino and EQBO had the coldest winter signal of all ENSO and QBO combinations.

I'm sure that when the jet is strong it typically gets much flatter. The winters of 2013/14 and 2019/20 both had a strong and flat zonal flow. Many times the jet got up to 200mph. The flat, zonal jet had more energy due to the stronger polar vortex and there was little to no amplification of the jet. The same principle applies in rivers where the fast flowing parts are generally fairly straight whilst the slow areas have meanders. In contrast winters of 2009/10 and 2012/13 had a much slower and therefore less energetic jet stream. Both of these winters featured frequent amplification and northern blocking as a result due to a weaker polar vortex.

One thing that seems to be interesting in regards to the polar vortex is how the vortex right up at 1hpa seems to be struggling to get going properly and has been weaker than average really for the entire vortex season so far Wonder if this will have an overall effect of weakening the vortex at all levels in the weeks to come and increase the chances of blocking episodes and a colder winter

Do note that both of these events were EP El Nino's which are typically associated with mild winters. Also both years were strong WQBO as well. 2023/24 isn't such a good match. The Nino is moderate / strong and is predicted to be more CP than both of those winters. Also a moderate to strong EQBO is expected.

The most important one for me for our SSW chances is all those indications of above average heights over Scandi and the Urals region. May they stick around there for a while even if we pay the price ourselves with troughs getting stuck around the UK and several weeks of wet weather.

LOL Don't you want to have a go at them all and come up with different ones to mine?

Just for a bit of fun I've tried to think up of winter theme names for what the weather models could stand for. I've taken these from meteociel and added any others I know of too. For anyone else who wishes to try this the rules are that you can only use 1 word per letter and the words have to be in the same order as the letters of the model and cannot be rearranged. Also the result has to be a phrase or sentence that makes sense. ARPEGE, PEARP, GFS, ICON, ECMWF, UKMO, JMA, DWD, GEM, CMC, NAVGEM, NASA, CFS, NOAA, CEP and CANSIPS are used here. ARPEGE Always Rainy Precipitation Expected Going Everywhere PEARP Predicted Everywhere All Rainy Precipitation GFS Generally Fabricated Snow ICON Icy Cold . . . . . . . . . . Or Not ECMWF Expected Continuous Mild Weather Forecasts UKMO United Kingdom Mild Outcomes JMA Just Marginal Action (On wrong side of marginal of course) DWD Dreary Wintertime Drizzle GEM General Expected Mildness CMC Classic Marginal Cold (We wish) NAVGEM Not Anticipated Very Good Expected Mild NASA. Never Anticipate Snow Again CFS. Can't Forecast Snow NOAA Never Overestimate Anticipated Action (Will be cold rain) CEP Close Expected Parameters (Not quite cold enough for snow) CANSIPS Can Anticipate No Snow In Precipitation Scenarios

Another snow event that ended up a lot better than expected was Thursday 12th Feb 2009. The forecast showed a band of light and patchy snow coming down from the north throughout the day, arriving in my location during the evening, maybe leaving a very slight dusting of snow. What actually did happen was the front was more active than predicted and arrived about 6 hours early and gave around 4 hours of steady snow that left a nice covering. Unfortunately that was also the last snow of that cold spell and the winter as a whole as the rest of February 2009 was mild.

Some interest here for later in the month with below average zonal winds showing throughout all levels. Maybe El Nino and EQBO finally kicking in.

C omplete F abricated S *** C omputer F antasy S cenarios C learly F antasized S now