Model output discussion - into the last third of January

[Phil Blake]

38 minutes ago, mushymanrob said:

Am i the only one who doesnt rate the MJO influence? Is there any corrobrative evidence that the MJO is much of a player? What state was the MJO in when we have had previous Big Freezes?

Seems to me people are grasping at straws for some kind of confirmation of a favoured weather type is likely.

Currently, imho, there is no sign of any developing Easterly, not in the ops nor my favoured NOAA anomaly charts ................................. but then again there wasnt in January 24th 1985 whos synoptic pattern was very close to whats expected by Tuesday next week. And we all know how February 1985 turned out!

Are the NOAA anomaly charts still showing a westerly flow into the UK? I wasn't born til Oct 86 so don't know how Feb 85 turned out lol

[Climate Man]

1 hour ago, General Cluster said:

You're absolutely right, Matt: despondency is futile: whereas, back in the Good Old Days, near-total ignorance set-in after about 48 hours, these days, it's likely nearer to 120 hours?

So, how can anyone write off an entire month/season based solely on one or two NWPM predictions? This time next month it might be 20C with blazing sunshine? But at the same time, it could be -5 with drifting snow?

Who knows? 

 

And that my friend is why, in a nutshell,  we have this hobby. 

[johnholmes]

I hope I may be allowed to inject some reality to what the weather may do 6-14 days from now, after this rather cold spell just starting, well for many areas as I know north of the border a good many have had a decent first half to meteorological winter.

Unless the anomaly charts are way of the mark then the 6-14 days shows no sign at all of any deep cold be it from the north or east. The 6-10 shows a 70%+ accuracy if giving consistency over a 3 day period with the 8-14 at about 60-65%.

Here are the latest charts, showing largely westerly for the UK.

My own comments for my files below this morning

Thursday 21 Jan

Ec-gfs much as yesterday, mainly w’ly 500 flow across pacific and atlantic, just two troughs, one off western and one off eastern n america seaboard, flow a touch n of w into uk,

And Noaa not much different. Contour heights around 534 DM central England, and strong flow, so fairly disturbed pattern and average to rather cold temperatures seems best bet for overall pattern for 6-14 days

ECMWF/GFS DAY 8-10 MEAN 500MB HEIGHT COMPARISON

WWW.METEO.PSU.EDU

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

Edited January 21, 2021 by johnholmes

[MAF]

8 minutes ago, johnholmes said:

I hope I may be allowed to inject some reality to what the weather may do 6-14 days from now, after this rather cold spell just starting, well for many areas as I know north of the border a good many have had a decent first half to meteorological winter.

Unless the anomaly charts are way of the mark then the 6-14 days shows no sign at all of any deep cold be it from the north or east. The 6-10 shows a 70%+ accuracy if giving consistency over a 3 day period with the 8-14 at about 60-65%.

Here are the latest charts, showing largely westerly for the UK.

My own comments for my files below this morning

Thursday 21 Jan

Ec-gfs much as yesterday, mainly w’ly 500 flow across pacific and atlantic, just two troughs, one off western and one off eastern n america seaboard, flow a touch n of w into uk,

And Noaa not much different. Contour heights around 534 DM central England, and strong flow, so fairly disturbed pattern and average to rather cold temperatures seems best bet for overall pattern for 6-14 days

ECMWF/GFS DAY 8-10 MEAN 500MB HEIGHT COMPARISON

WWW.METEO.PSU.EDU

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

John, can i just add that what a lot of the UK is experiencing is, in a time ago, what would be expected of a 'normal winter'; cold interspersed with not so cold, wet, windy, wintry in prone regions, frosty and foggy. if temps and conditions remain average over winter then i think its an improvement on a good few winters previous to this one. the constant search for extreme winter conditions in this temperate island eludes me. 

Edited January 21, 2021 by MAF

[damianslaw]

Looking at the immediate outlook, FAX charts suggest heights to the NW holding out a bit more longer lasting influence, with the signal for any secondary low pressure features to move on a more southerly trajectory into France over the weekend

End result - a cold showery NW airstream, cold enough for snow to low ground at times in the north especially where any troughs develop. It is a fairly unstable airflow, so such features likely to develop quickly.

Into next week Atlantic breaking through but may struggle to make quick inroads across north and east, snow possibly significant in northern parts ahead of the Atlantic attack.

Not looking beyond early new week. 

[Kirkcaldy Weather]

27 minutes ago, Battleground Snow said:

The 2018 event sticks in my mind.

Can somebody link the historical plots, I can't find them?

Using the bom site data, prior to the BFTE MJO was phase 6 amplitude 3 January 27th - 31st then phase 7 from 1st February- 18th February (amplitude 3 was 1st-11th, amplitude 2 12th-17th then the 18th was amplitude 1, I’m not sure if the higher amplitude is always important even with recent 0 amplitude phases the patterns haven’t been far off those associated with them, I assume higher amplitude means a stronger pattern etc. The phase I think would be most beneficial is phase 7 that looks to be the one which would favour easterly(s) I will start with the phase 6 charts should we end up with that too, seems to be associated with higher pressure somewhere around uk though still also northern blocking  and here’s phase 7  also found this on twitter which might prove relevant, I put the blue box around the one we would be looking out for the most  so we might be coming up for another spell where the models begin to try figure that out and still the ongoing strat events, wouldn’t be surprised if we see some nice colder charts coming out and hopefully the majority in here can try and enjoy the output without assuming every possible cold spell won’t happen, they can and they will, will that be another BFTE who knows.

[tesaro]

4 hours ago, sebastiaan1973 said:

 

Anyone that uses the word “Definitely” when talking about the Weather is either a Time Traveller or just over confident in themselves.

[mushymanrob]

52 minutes ago, Battleground Snow said:

This is from the WMO.

so in answer to your question or rather statement @mushymanrob, there does appear to be *some* evidence

 

The cold event March 2013 coincided with the propagation of a Madden Julian Oscillation (MJO) event into the western tropical Pacific. Studies (e.g. Cassou 2008, Lin et al, 2008) have shown that an active phase of the MJO over the western Pacific is conducive to negative NAO. Was this MJO event responsible for the cold event over Europe? To establish if there was a link between this MJO event and the cold March 2013, a composite of 2-metre temperature anomalies of the 10 ensemble member forecasts which predicted the strongest MJO event were compared to a composite of 2-metre temperature anomalies of the 10 ensemble member forecasts which predicted the weakest MJO for each individual forecast system (as for 2-metre temperature, MJO forecasts varied greatly between ensemble members). Results from the ECMWF model (Figure 3) and the NCEP model (figure 4) suggest that there was a strong link between the MJO event and the cold anomaly over Europe, with the ensemble members with a strong MJO predicting 2-metre temperature anomaly patterns more consistent with observations than the ensemble members with a weak MJO. The ensemble forecasts from Environment Canada showed the same link between good MJO forecasts and good 2-metre temperature forecasts 

 

Thanks.... so a stronger MJO signal has more influence (and with other factors taken into consideration)

46 minutes ago, Badgers01 said:

feb 85 was a fairly unremarkable month not sure what the relevance for now is ??

 What @MJB said, summed it up perfectly
 

32 minutes ago, Phil Blake said:

Are the NOAA anomaly charts still showing a westerly flow into the UK? I wasn't born til Oct 86 so don't know how Feb 85 turned out lol

Yes, as @johnholmes has said.

Ive just done a bit of research into cold following a SSW, a cold spell can start as early as 12 days through to 54 days following a SSW. But not all SSWs produce as we know, others have colder spells, others have a proper cold spell. But that was a rough overview. It does suggest though that we have until early March to eventually get a proper  cold spell.

[Youcan'tbecirrus]

35 minutes ago, Climate Man said:

Yes but generally only when there is snow in the air.

Or a Greenland High knocking about.........those that know know. He is a good poster, enjoy reading what he has to say. 

[summer blizzard]

The SSW has already downwelled as per the Berlin charts and indeed the AO is negative. What we need is another wave attack to shift the position.

[feb1991blizzard]

2 hours ago, Tim Bland said:

Isn’t that what fell last night

Nope, that went within an hour of it stopping.

[Weathizard]

Regarding the SSW for people more ITK than me regarding it, could the fact the vortex was already a disorganised mess have meant that the downwelling didn’t make as noticeable a difference as it would in a normal winter with an organised PV? It’s been an odd winter given that the vortex hasn’t really been strong, yet we’ve had a very, very wet winter.

 

 

[BlueHedgehog074]

A bit of focus on next Tuesday, for example, models such as the 00Z NAVGEM would be one of the better case scenarios for the cold weather fans. Quite a sharp angle to the approach of the Atlantic Low with it looking pretty squashed. It disrupts and pushes a small Low through Central UK. Provides a slower progression to the milder weather trying to spill in from the South-West (bare in mind that NAVGEM can be a bit biased I feel towards positive 850 hPa temperatures). Mostly sleet and snow I would imagine around Central/Northern Midlands Northwards during Tuesday 


 

Something that would be nice to see other models such as the UKMO make more off not being too quick trying to push the Eastern part of the Atlantic Low Eastwards through the UK on Tuesday. Have it more squashed and disrupted like the NAVGEM. There really is no need to be in a rush, Atlantic Lows. Might do you Lows some good to go out for a stretch

Admittedly, when using models like the NAVGEM, makes you realise there’s a bit of desperation from my part going on But illustrates something that could do with happening for a more possible widespread wintry event for Tuesday or Wednesday next week. 

In the meantime, the next few days look chilly with a flow generally from a West to North-Westerly direction. Showers, wintry at times, towards North and Western areas, but a chance of some more organised areas of rain, sleet and snow at times. More so towards Southern areas during the weekend, as models show some disturbances heading Eastwards/South-Eastwards through the South of the UK. Exact track of these features still a little uncertain, but the chance is there for a few wintry surprises

Edited January 21, 2021 by DiagonalRedLine
Rewording first sentence

[Matt H]

Sunday still looks like the best day for most people across the south to see some falling snow according to the ICON 12z.

 

[AdrianHull]

1 minute ago, Frosty Winter said:

Sunday still looks like the best day for most people across the south to see some falling snow according to the ICON 12z.

 

I really hope you guys get some but unfortunately it looks like it will be very marginal and more than likely a slush fest.

[Tim Bland]

6 minutes ago, Frosty Winter said:

Sunday still looks like the best day for most people across the south to see some falling snow according to the ICON 12z.

 

Looks like it stalls a bit as it heads east. Patches of 10cm over Cambridge area..

[Froze were the Days]

CFS still running with it's blocked signal into Feb - 6z from Greenland high to somewhat of a lull then to a Scandi after mid-month. It's not going away.

 

Edited January 21, 2021 by Froze were the Days

[sebastiaan1973]

3 hours ago, Frosty Winter said:

I think we just need to be patient and hope that the signal for a cold easterly during February continues to gain support. 

 

Curious about EC46 of tonight!

[Bogman]

20 minutes ago, Tim Bland said:

Looks like it stalls a bit as it heads east. Patches of 10cm over Cambridge area..

C'mon Tim. Been here before mate.  

Edited January 21, 2021 by Bogman

[Mark wheeler]

The little feature is there on the Ukmo , Just

[frosty ground]

Hello random wedge!

[Tim Bland]

12 minutes ago, Bogman said:

C'mon Tim. Been here before mate.  

Haha yes, many. Broken hearts in Herts this year ? GFS & GFSp have nothing for large parts of the east / south east this weekend. If ECM agrees it will probably be another opportunity down the pan. If I wasn’t so bored in lockdown I’d have rolled up my towel and be ready to launch it by now I expect

[sheikhy]

!!!!!bring on the summer at this rate!!!ukmo looks like its hardly got a feature for sunday!

[swfc]

Afternoon. Looking over the next four days I'd be thinking that a few snow chances are on the cards ie showers and any small lows zipping threw on a southerly jet. Has northwestsnow mentioned the further outlook Dosnt lend itself to anything really wintry ete. Things seem over the last ten days to have moved away from anything other than a westerly flow with a ridge thrown in. So in essence average January weather with the the caveat that no real PV in place. Looks like the boat has been missed during this period for a memorable cold spell altho the cet would suggest different. Snow I'm my area has been around but generally UK wise its not been great. Still time but the original thoughts and hopes post Xmas seem to be weakening. Hopefully the nhp will threw out some big changes and bring a decent cold spell. Stay safe

[chris55]

9 minutes ago, Mark wheeler said:

The little feature is there on the Ukmo , Just

GFS has it as a little slider. Any Snowfall could be quite localised depending on track intensity etc.