Model Output Discussion - Spring Has Sprung

[Mike Poole]

  @MJB That signal in Greenland for w/b 12th is the strongest since the runs go back to (9th Jan).  Also, there are signs of a transition to it the week before which wasn’t previously evident.  

[Kirkcaldy Weather]

No need for me to spend too much time adressing those who still like to bash and dismiss the teleconnective aspects and in turn us that base our work / posting on them, I'll refer to my post from 7 months ago

 

I can assure everyone that the 500hpa setups which are developing are very much in line with said teleconnective feedback. So building on from my previous post 

 

I've not done a single post over in the stratosphere thread since October 12th 

 

however 104 days on I feel its time to add my input

Everything is coming together nicely through the rest of Jan and into February 

 

Starting with how the Stratospheric Vortex has behaved of late, using the zonal wind data off stratobserve we note there was a reversal in zonal winds albeit relatively brief in nature 

Classification on stratospheric warmings are a bit of a point though I'd hazard a guess we can technically class that as a major SSW but I'll leave that aspect to those who specialise in the stratospheric element.

Credit Butler et al 2015 to explain my above statement 

You can also see from the zonal winds we've seen a quite rapid increase to a point which is hovering roughly slightly above - on average for zonal winds at this timeframe however we are seeing an excellent showcase of the 500hpa and surface temperatures as a result of a stronger vortex.

Bear in mind this includes La Ninà responses however it's effectively the same.

As discussed in my previous post and in line to MJO feedback these are paired to bring above average temperatures across wider swathes but there are still colder temperature anomalies which become focused over the southern regions in the Northern Hemisphere again a good amount moving into Asia, also Greenland, Alaska and the West Coast of America go below avg.

Patterns we are witnessing into February are exactly what to expect 

b and d 

e and h ignore the ticks that is from a post I done last year, however those are pretty close to the patterns we've had during our recent cold setup

Heading through the 1st week of February we are seeing precursor 500hpa pattens which are conducive for stratospheric warming(s)

We'll also have feedback from the MJO entering the Pacific.

As things stand we're looking at at least two weeks of the MJO being active in the Pacific roughly January 24/25 through January 7th but the extended data is supportive ATM of a 3rd week still prominent within the Pacific Taking the progress into / nearer Mid January 

This also plays into stratospheric warming with phases 6 and 7 having a stronger correlation with weakening the stratospheric vortex and a large portion of prior warmings having occured with the MJO within the Pacific 

 

All classic El Ninò characteristics into February week 1

 (a)

Thanks for reading.

KW

[Dennis]

EC WIIL change on its 500hpa charts

 

[MATTWOLVES 3]

Personally I think theres plenty of ec ens that are bringing about a much more favourable placement of the pv, and the profile up above looks much more primed too me.. I actually thought the gfs 12z ens were OK to but it seems you can't please everyone. For me we are becoming licked and loaded for winter to make a return towards end of week 1 Feb.. or thereabouts!

[Rain All Night]

8 hours ago, RainAllNight said:

0z deterministic runs, Wed 24th to Wed 31st

Each time it looks as though a sustained dry spell might build, something comes along to interfere with it. Still, there are plenty of shorter dry periods showing here, especially further south.

0z ensemble means, Wed 31st to Wed 7th

The PV seems to go east, only to then possibly come back west again soon after. The heights to the south seem to gradually recede from their peak at the beginning of this period.

12z deterministic runs, Thu 25th to Wed 31st

In the last few frames here, we see that westward shift of the heights to the south that has been showing on the ensemble means for the past few days. Down south, we seem to be able to make a dry stretch last from Friday PM until Monday-ish. UKMO manages to get some modest high pressure to the north by the end of its run.

12z ensemble means, Thu 1st to Wed 7th

ECM seems especially confident about the PV paying a visit to northeast Europe on the weekend after next, but it is equally bullish about high pressure remaining strong to our south, hopefully at least meaning that we continue to get some decent stretches of dry weather further south.

[Dennis]

Good signs on a greenland High 

[WYorksWeather]

ECM well on its way now, so here goes.

First off, we have the ensembles, which broadly similar to the GFS are showing above average temperatures at 850hPa level and at the surface. The latter especially by night, and a little above average by day.

Then, we have the mean charts at day 15. Even worse than the GFS with not much relaxation of the Iberian heights, and the 0C 850hPa line pushed back to northern England. Nothing to see here, except possibly somewhat less mild than earlier on with more of a westerly rather than south-westerly.

The meteogram for Reading also illustrates this. Temperatures almost always above or at most in line with the 20-year average, the mean direction is never anything other than westerly, south-westerly or southerly, with small chances of a north-westerly and close to no support for a northerly, north-easterly or easterly.

The ECM has a mean 850hPa at one point at 11C, with some ensembles getting to 14C, and we'll be lucky if we even get one or two frosts in the next two weeks, let alone any snow, if this chart verifies. I'm not even going to attempt to sugar coat this.

Suggested course of action:

• Print off copy of charts
• Take them outside
• Set fire to them
• Run away

What do you say we try again tomorrow?

 

 

[northwestsnow]

  @WYorksWeather

EC and its suite seem conflicted to EC 46 ?

 

[johncam]

  @northwestsnow are the EC46 not run 00 hours?

[Rain All Night]

11 minutes ago, johncam said:

@northwestsnow are the EC46 not run 00 hours?

Yeah. And they're run at a different resolution and with a different number of members (since June 2023).

Edited January 24, 2024 by RainAllNight

[northwestsnow]

I hope things haven't gone backwards this evening I was actually happy with EC 46 but forgot its run off 00z data.

Edited January 24, 2024 by northwestsnow

[blizzard81]

  @northwestsnow no need to worry as the 12z ecm ens suite is very similar to this morning's. 

[Metwatch]

Weakening of westerlies in the troposphere at 60N modelled by latest GFS into February, at least compared to the next 7 days, one to watch to see what that will do.

 

[Daniel*]

Better before day 10 on GFS 18z, ultimately similar in our locale but upstream much more amplified. 

[Don]

1 hour ago, northwestsnow said:

I hope things haven't gone backwards this evening I was actually happy with EC 46 but forgot its run off 00z data.

There's going to be many backwards and forwards with the models during the next few weeks, that I'm sure of! 

I too thought the EC46 looked better this evening.

 

[feb1991blizzard]

Close to an E'ly on 18z. and not 384 either.

[feb1991blizzard]

And having another go at the end as well, not sure this fits the expected strat pattern though.

 

[LetItSnow]

Unlikely to be exactly correct but on the 0z it throws a ridiculously mild chart for February 2nd.

Projected maximum temperatures widely in the mid teens with a couple 16Cs dotted around. You can usually add to that. Looks like we could potentially start February 2024 similarly to how we did exactly twenty years ago.

On February 3rd, 2004 temperatures rose as high as 17C. You wouldn't be surprised if the projected pattern could do the same. 

Only caveat as that while a very mild start to February is on the cards, slight adjustments could mean slightly less (but still exceptionally above average) mild temperatures.

[joggs]

Charts still showing mild all the way in the reliable. Good for bills. Vile for us coldies.

Edited January 25, 2024 by joggs

[IDO]

No change in the GEM and GEFS mean for D8-16:

 

Flat, westerly and zonal N/S.

This takes us to Feb 10, and we seem to be in a rut of a pattern. We await background signals (warming, MJO, etc.) to push some forcing into the regime; otherwise, the alpha tPV seems happy as Larry is stuck on our side of the NH.

We are likely to see random op runs and the usual ens that may show something different but with such a strong mean, these charts are likely just aberations of the algorithms.

[TillyS]

The faintest of faint glimmers on the 0z ECM at T240. There’s a possible evolution from this of the high retrogressing into mid-Atlantic:

 

Otherwise, exactly as @IDO says above.

Edited January 25, 2024 by TillyS

[Lukesluckybunch]

Another rough run from the ecm this morning..fleeting shots of cold at best,look the best chance for the next 7-10 days..longer rangers prefer mid too late February for something more prolonged!

[Dennis]

hi all

Well all 500Hpa charts have problems to other paramaters .... lets see next days (between 3-5 febr)

Forecasting is to a -NAO

[AO-]

  @Lukesluckybunch

Good Morning,

Yes, it does. Cold is swept into Eastern Europe. However for here the EPS improved (a lot). Something possible around the 10th. 

Todays vs tuesdays EPS

Wind probability

Chance of easterlies increased a tad

Edited January 25, 2024 by AO-

[bluearmy]

Euro heights beginning to fall away end week 2 going into 3 

could be a continuation of the zonal flow with a bit of amplification chucked in but that would introduce some wintriness ahead of stronger signals in mid feb