Model Output Discussion - Spring Has Sprung

[Mike Poole]

ECM clusters this morning T192-T240:

Cluster 1 hangs on to a continental flow to the UK to T240, the others essentially a return to westerlies.  The key thing seems to be the low out in the Atlantic at this time, if it is kept further west and shallower as cluster 1, then the block is stronger and the Atlantic held at bay.

The zonal wind reversal in the strat has now happened, and the peak reversal about -14m/s expected in about 4 days - it will be interesting to see whether there are changes in the week 2 modelling as this goes through.  If it is having an immediate effect, I would expect to see the block showing more resilience in runs to come.  If its effect is still some time down the line, that probably wont happen.

[feb1991blizzard]

 Mike Poole

I think effects will start to show in the modelling once the split is within the reliable, its D10-15 now.

[Rain All Night]

11 hours ago, Rain All Night said:

12z deterministic runs, out to Mon 11th (day 7)

I won't even try to comment on the mess beyond day 4, I just know I don't want the GFS to verify!

12z ensemble means, out to Tue 19th (day 15)

As has been the case for the last several runs, ECM is putting up much more of a fight against the Atlantic than GEFS. But the two do agree that high-latitude blocking is likely to have disappeared by the end of the second week of March.

0z deterministic runs, out to Tue 12th (day 7)

Southerly incoming..?

0z ensemble means, out to Wed 20th (day 15)

Same as the last few runs really, ECM offering the most hope that the developing Atlantic trough will be stalled.

[Lukesluckybunch]

Icon 6z looks nice..after 120 I would say there's a good chance of that very cold air from the east!

[CoventryWeather]

Away slightly from the relatively uncertain reliable, there's been a trend to deliver quite significant warmth to the Mediterranean and Spain over the past few days, towards the end of the month. The latest GFS pulling some out into the Atlantic by 384. 

Perhaps signalling a warm (dry) spell in Europe is not far away, when was the last time we had an warm April/May period? 

[*Stormforce~beka*]

 CoventryWeather 2020

[Rain All Night]

I hope we can find a way for the Atlantic bowling ball to fail to reach our alley once our little easterly is done with.

[Lukesluckybunch]

ICON 12z appears to be running a bit late...

[Man With Beard]

GFS 12Z keeps the low running up the channel. Likely that it will correct south into France as channel lows tend to do in winter...

... strike that - since it's just about too warm for snow, instead it's going to be a bullseye hit for the south with copious amounts of rain.

This really has been the mother of disappointing winters.

 

Edited March 5 by Man With Beard

[Lukesluckybunch]

Ecm horror show tonight!southwesterlies coming back in!

[johncam]

Block blown away as usual 

[Theresnoway]

 johncam I’m not predicting some kind of winter nirvana, but blocks do tend to put up more of a fight than often modelled. So some kind of a middle ground would be most likely IMHO.

[johncam]

 Theresnoway just looking for a few consecutive sunny days

[lassie23]

I think we are in for a bone-dry summer, nature has a way of evening things out, so enjoy the rain for now before it vanishes over the summer months.

[stodge]

Evening all

A far from spring like weekend approaching with a fairly deep LP scheduled to be close to southern Britain by Friday and moving only slowly east into the early part of next week.

The removal of heights from Scandinavia means there's nothing to stop the next LP aligning positively and with heights building back into the western Mediterranean it looks as though it will turn milder next week but not really settled with rain never too far away especially from western and southern areas.

Signs of another trough disruption later in the month but little sign so far of a tropospheric response to the SSW. 

12Z GFS Control is perhaps the most interesting in terms of keeping the PV over Siberia - other models try to feed the very cold air back across the Pole.

I'm not sure the post-weekend evolution is anywhere near resolved as yet but the disruption of the trough to the south looks to be within the reliable.

[Mcconnor8]

 lassie23 I think historically a summer that takes place during the transition to La Nina from an El Nino is wetter than average, which is what is expected currently, but I really hope we do get that dry summer as the rain really has been relentless for 8 months now.

[raz.org.rain]

 lassie23 it would certainly make sense. I don't much believe in the whole balance of nature thing, nature does what it does... but such extended and entrenched patterns do generally tend to run their course and flip to an opposing pattern. I think the analogues still line up with 1995 and 2022? Generally we'd expect that warmer and drier years will occur more often, so who knows.

[stodge]

Just glancing at the 12Z CFS - if northern blocking is your thing, you're going to enjoy April this year.

[Rain All Night]

11 hours ago, Rain All Night said:

0z deterministic runs, out to Tue 12th (day 7)

Southerly incoming..?

0z ensemble means, out to Wed 20th (day 15)

Same as the last few runs really, ECM offering the most hope that the developing Atlantic trough will be stalled.

12z deterministic runs, out to Tue 12th (day 7)

On GFS and UKMO, it almost looks as if the block could find a way to hold out...

12z ensemble means, out to Wed 20th (day 15)

The ECM ensemble still wants to believe that there might be a way to stall the Atlantic advance. Not sure why some of the frames have glitched out, mind you...

Edited March 5 by Rain All Night

[feb1991blizzard]

how about this wild fluctuation on eps.

[Rain All Night]

6 minutes ago, feb1991blizzard said:

A few more decades..?

Edited March 5 by Rain All Night

[WYorksWeather]

Both main model ensembles sticking to their guns at the moment. Nothing spectacular due. Be very wary of taking too much from the OP runs. We keep alternately drawing them from the top and bottom of the set - no reason to go on the hope and despair merry-go-round whether it's warm or cold you're looking for. The broad pattern of temperatures near average for the time of year is pretty well fixed. Other options are available, but they're mostly outliers in the ensembles and have been for several days. Don't be fooled.

The meteogram wind plume continues to show that we have a bit of a predictability barrier around the 12th/13th.

Perhaps the only thing of note for the longer range is a bit of a signal to start to draw heat from Africa into southern Europe around day 10. More pronounced on the GFS than the ECM, but worth keeping an eye on. Increasingly, as we go later into March, that would offer the prospect of our first warm spell of the year if we tapped in to it.

[feb1991blizzard]

Of course pie in the sky but this ens member just proves it is still possible to get ice days and blizzards deep into spring.

And if a clairvoyant were to tell me this was going to happen next winter and asked me to guess between December or March, i would pick March.

[KTtom]

 feb1991blizzard not sure it proves its still possible to get ice days and blizzards or just that its still possible for a rogue ens member to thow in a big outlier...anyway...just getting a feeling the flicking of a switch is about to occur as we move out of the wet season into the dry season..get the car washed whilst you can

[JoeShmoe]

 KTtom bank that, would feel very springlike with temps at 13-15c and sunshine !