Model Output Discussion - Spring Has Sprung

[damianslaw]

Continued signal for azores heights to eventually advect back west for the last week of March introducing a chillier feed from the north. Until then we see the azores high trying best to ridge through the UK and settle things down in the week ahead but too much energy in the northern arm of the jet, ultimately thwarted as the trough eventually pushes east, but it will be a slow protracted affair. End product, mild but very cloudy and wet in the north and west, very mild and less wet and dull further south and east with fleeting sunshine. All tedious in my view.

Edited March 15 by damianslaw

[Downburst]

Ah yes, April is a flip a coin forecast for regimes. Sorry to say this but looking at the ECM monthly 500 charts it does seem to indicate similar to March in terms of rain. We shall see, a good week or 5 days somewhere in there surely.

[JakeWorces]

aaaaand GFS has once again switched from '6 day dry spell' to rainmageddon. 
It really is struggling lately isn't it, with these unhinged polar swings to the complete opposite forecast from one day to the next. 
She needs rehab.

[Rain All Night]

On 14/03/2024 at 12:34, Rain All Night said:

0z deterministic runs, out to Thu 21st (day 7)

The Azores high extension is heading towards the reliable timeframe, but how much of an impression will it make on the UK?

Before that, a little ridge passes over us on Saturday, perhaps followed by an unpleasant-looking low pressure system on Tuesday.

0z ensemble means, out to Fri 29th (day 15)

The signal for what happens after the Azores high extension remains vaguely suggestive of something cooler coming from the northwest, but there isn't a strong Atlantic ridge signal to go with this any more.

0z deterministic runs, out to Fri 22nd (day 7)

Might spring be springing at the end of next week - for some of us at least - thanks to the Azores high?

0z ensemble means, out to Sat 30th (day 15)

It still looks like the swelling of the Azores high will be fairly brief, and that the pattern will then change to one with a more northwesterly vibe, with some kind of trough feature forming to our immediate west for the end of the month. I'm sure that'll be just lovely...

Edited March 15 by Rain All Night

[Summer8906]

 Rain All Night 2024... the year without a spring? Beginning to wonder...

(following 2023, the year without a summer, and 2023/4, the non-winter, of course).

Agree that the whole thing has shades of 1998 about it, though the first half of the month was more 2023. Hope we don't start April with a devastating flooding event, not liking the look of that mean cyclonic setup, it looks rather early April 1998 like. Still, hopefully won't come to pass.

Edited March 15 by Summer8906

[Alderc 2.0]

 Summer8906 2023 didn’t have a spring either….

[Don]

Just now, Alderc 2.0 said:

2023 didn’t have a spring either….

It did, you're thinking of 2013! 

[*Stormforce~beka*]

 Summer8906 We had no spring last year either! The doom and gloom started in March and stayed!

 Don For northerners maybe!

[andymusic]

GFS 12z - Easter looking a tad cold again

[Summer8906]

 *Stormforce~beka* We got 6 solid weeks of sun here from May 13-June 25, so it felt like we did have something of a spring, albeit a late one. Also it was colder last year meaning the flowers were still out when the weather finally improved.

[Summer8906]

 andymusic Just have to hope that the high keeps that horrible low to the southwest at bay...

[Addicks Fan 1981]

 andymusic don't think it'll be backed by the ensemble mean though.   I'd suggest anomoly charts are a better indicator of where our weather is going like @mushymanrobuses or used on a regular basis.   Come to think of it we need @johnholmeson here as it would enlighten us of the goings on a bit more.     

[*Stormforce~beka*]

 Summer8906 I didn't but I'm further inland than you. I had 1-2

[WYorksWeather]

Gah, that is a disappointing downgrade from the GFS 12z. Reeling in the dry and mild/warm spell to day 7 now, all looks OK:

By day 9 though, the usual sinking high rubbish ends up happening, and normal service is resumed.

We should frame that last chart to sum up the period since July. No less than three large areas of high pressure - one over Greenland, one in the mid Atlantic, and one to our south east, and somehow the low finds its way to us.

Fewer ensembles going down the sustained high pressure route as well than there were, it does now look like a 2-3 day affair. The ensemble mean largely follows the same trajectory as the OP today, hence why I didn't bother posting it.

Separate post to come on the ECM later, but not a great 12z GFS tonight.

 

[LetItSnow!]

 WYorksWeather

Could be pleasant in the south but that chart while mild doesn't exactly scream walk in the park conditions as those flabby westerlies look like they'd bring a fair bit of cloud and even outbreaks of rain further north.

[stodge]

Evening all

To be fair, if you're interested in unusual synoptics or want a good spell of dry weather, there's not much for you in tonight's offerings at least in the short term.

The next 10 days offer a bit of sun, a bit of rain, a bit of warmth but nothing to worry about too much. We might see a 16 or 17c over East Anglia next weekend if all goes well. The pattern which kicked in on January 22nd has broadly speaking been maintained, what I would describe as on the wet side of benign.

Hints on some of the GFS members (including the OP) of a break in that pattern as the PV finally edges over to central northern Canada and we get heights and warmer air into Greenland which changes the pattern over us to a more traditional battleground of warmer vs colder airmasses and as we approach Easter the colder air wins temporarily but this is a long way from the reliable (the earliest hint, the PV starting to move west is at T+192) and only eye candy at present but it would be the law of sod to have a much colder regime come in for Easter.

[Jordan S]

 Addicks Fan 1981

An unsettled/very unsettled end to the month evident on the second chart from noaa, with less unsettled few days in the south then changing to a cyclonic one, heights over Greenland.

Air not particularly warm nor cold but northern hill snow risk as is entirely normal for the time of year and ties in with my thoughts since 8th March, though perhaps less wintry aspect than I thought may be the case, would give widespread cold and snow risks no more than 10-20% chance for easter period. Could be dealing with very slow moving fronts parked over UK, as stubborn heights may reside over central/Northern Europe for a time, then that weakening into first week of April with a possible drying trend for a time in the north and northwest, and continued unsettled south/east UK though with winds east/northeast certainly possible for a time.

[WYorksWeather]

ECM also going for the downgrade.

Bit of an odd setup but even that period from day 7 to 10 which is the best of it will probably only be mostly dry in the south - areas further north will struggle I think to get even a couple of consecutive dry days.

Ensemble isn't out yet, so I think all we can do is hope for the OP to be on the low side for the extent of the Azores high.

[Addicks Fan 1981]

 WYorksWeather I'd percieve it as the op charts are starting to fall in line with what the ensemble mean are implying here where the ECM is concerned, also the MJO is set to get a little bit weaker as well with not really a coherent signal going forward.    

[Kirkcaldy Weather]

Adding some more detail to the above post, further excellent representation of MJO feedback 

With further feedback including that of phases 4 and 5 we'll see a number of noteworthy developments.

As discussed in the above post the next movement of the Tropospheric Vortex during the next 7 days approximately sees the TPV begin to split with the main lobe heading across the Kara Sea into Russia with secondary lobe(s) moving into Canada and the Canadian Maritimes.

The next cyclone to approach Ireland and the UK will transition into a cut off low which heads through Spain and into Northwest and Northern Africa, likely rossby wave breaking involved.

Also note the cut off high as mentioned previously and the trend into a trough dominating pattern beginning from Canada toward the Great Lakes and Northeast America.

Per the above there will be opportunity for the Atlantic - Azores High to ridge across more southern parts of the UK and Ireland.

Another main aspect of phases 4 through 5 is the building of a strong Pacific > Alaska > Arctic Ridge and Blocking regime which extends into Greenland likely more of a -AO during this sequence.

[WYorksWeather]

 Addicks Fan 1981 I think the ensembles have also downgraded slightly though as well.

[WYorksWeather]

The GFS 18z is a case of an improvement in one aspect and worse in another. On the positive side, it keeps the high in place from around day 5 to day 10.

In deep FI though, the GFS blows up a low and fires it at us, and the Atlantic conveyor belt is off again.

Going to adopt a new motto, adapted from the winter one. Let's get the dry weather in first, then worry about what happens next...

[Snowfence]

Looks like an Easter snow flurry and settling on the highest hills - and may be elsewhere in the early morning, if the 0z GFS Op is to be believed in +300 hours.  However, I have a hunch this tease of the tail end of wintry possibility might verify, against all odds, but I am prepared to be woken from my dream of seeing a flake before summer, and perhaps with a slap from a wet salmon. Fingers crossed. Spring snow is very special in its crystalline beauty - even if it melts within a hour or two.  

[Beanz]

 WYorksWeather we’re 3 weeks into Spring, it’s nearly April - when you say better/worse, upgrade/downgrade, that doesn’t really explain much to anybody reading your post and charts. 

 

[Anthony Burden]

Morning all, GFS not giving up on a sting in the tail for March will the SSW show it’s late hand or not that is the question.Personally high pressure bringing dry weather where ever it’s position be it northern blocking or not is what we desperately need in England to dry out.