Model Output Discussion - What does April have in store?

[Don]

1 hour ago, damianslaw said:

Last year brought a very good may day bank holiday, would do well to see two in a row.. is someone playing with the weather at the moment ensuring our holiday seasons coincide with good outside weather?... timings of changes seem to be coinciding just in time for these..almost to good to be true..

I'd welcome some thoughts from more seasoned forecasts - experts so to speak, why background drivers at the moment seem to consistently be favouring warmer and more settled patterns than colder and / or less settled ones since this time last year..

Yes, we have been lucky recently with good weather coinciding with holiday weekends, unlike a few years ago.  As to what background drivers have driven the consistent warm pattern of the last year, I'm not sure.  However, whatever they are, they have likely had assistance from the ongoing warming climate.  I cannot see the pattern change anytime soon, either.

Edited April 27, 2019 by Don

[Frosty.]

This is my pick from the longer term GEFS 6z.

[Frosty.]

I imagine this would feel quite cold on the 3rd May from the ukmo 12h 

[Frosty.]

21 minutes ago, Frosty. said:

I imagine this would feel quite cold on the 3rd May from the ukmo 12h 

Indeed it would, especially uuuppp north

[chrisbell-nottheweatherman]

22 minutes ago, Frosty. said:

I imagine this would feel quite cold on the 3rd May from the ukmo 12h 

Showery on this side of the country as well, presumably?

[Frosty.]

1 minute ago, chrisbell-nottheweatherman said:

Showery on this side of the country as well, presumably?

Yes, cold and showery especially further east if it verifies, even some wintryness on northern hills and widespread frost risk.

Edited April 27, 2019 by Frosty.

[Methuselah]

GFS has the weekend fine enough. But for how long?

 

[Frosty.]

Well clearly the Gfs 12z operational isn't buying what the ukmo 12 is selling, the gfs looks really pleasant temperature wise in comparison and although it becomes showery, especially wednesday, the showers risk decreases thereafter with a largely settled and warm weekend across the board.

Edited April 27, 2019 by Frosty.

[Methuselah]

Could this be (after four straight day's failed rainfall) the start of a long-lasting relatively dry spell?

 

[Methuselah]

I think this has the makings of a recurring pattern; a pattern that will not do much, as far as ameliorating the burgeoning lack of rainfall is concerned...?

 

[Cheshire Freeze]

1 minute ago, Ed Stone said:

I think this has the makings of a recurring pattern; a pattern that will not do much, as far as ameliorating the burgeoning lack of rainfall is concerned...?

 

Hasn't stopped raining for 12 hours+ here

I get what you're saying though, we're repeatedly seeing LP having a hard time dominating for any length of time. Either pressure is rising from the S or the Azores HP is constantly nosing in from the SW. 

[Northwest NI]

1 hour ago, chrisbell-nottheweatherman said:

I've been trying to get a similar opinion, but I think the experts are understandably reluctant to speculate!  It does seem strange that, with a weakened Jet thanks to lower polar ice expanse, the balance between blocked under a ridge vs. under a trough is as uneven as it is.

Anti cyclonic weather has never in my life been so prevalent as in the last 18 months. I keep expecting the return of the SW train. It would be nice to hear some informed analysis.

[Methuselah]

FV3 says next weekend will be okay:

 

[Methuselah]

And here's the 12Z GEFS temp ensemble: 

[Frosty.]

Nice..very nice from the Ecm 12z..a bit plumey 

Edited April 27, 2019 by Frosty.

[knocker]

This evening's ecm is keeping to the indications of the recent anomaly charts vis the holiday weekend and at this stage, no further definitive clarification/

It is still very dependent on how well the ridge resists the energy swinging north east around the Atlantic trough and thus the position of the surface high cell and any fronts pushing in from the west.

Saturday is okay except possibly N. Ireland and western Scotland. Patchy rain over N. Ireland and Scotland on Sunday with a freshening south west breeze over England Wales but dry. Quite windy on Monday with showery rain moving east over the country, apart from the south east. with a low just NW of Scotland. But next weekend is a long way off so really just to be noted

Edited April 27, 2019 by knocker

[Mike Poole]

Some charts from the 12z suite, first GEM at T240:

This one is probably the jackpot scenario, so good that it is on the table, ECM same time:

NW/SE split on this one.  GFS here T192 and T384:

All portends a decent bank holiday weekend with power to add.

Edited April 27, 2019 by Mike Poole

[SunnyDazee]

7 minutes ago, Mattwolves said:

I think things are looking up sunny, the guys posts above look very encouraging.... Don't ask me though... My last post took to much out of me, I'm spent now!! Seriously though, things looking so much better than the last few days... Bank Holiday could be warm and settled... The jet stream is going off on one again, its a meandering wreck...

If a meandering wreck means that I don’t have to have the heating constantly on I’m all for it lol. That’s good news anyway I’ll give it a check now. Honestly this is the worst weather we’ve had since the snow in late January. Worse than most of December and January in terms of just how bitter it is too. Crazy to think it’s May next week you’d think it’s November with the rain and February with the temperatures! Seen some good signs on the Beijing Climate Centre output, looking roasting across June, July and August. Possibly 2 degrees above average. Back to current times though I’m expecting change for the better as things can only get better (Sorry D:Ream!) after today I’m sure of it

[Frosty.]

Whoa I like tonight's Ecm 12z ensemble mean....a lot!!!

Edited April 27, 2019 by Frosty.

[Mike Poole]

ECM ensemble mean at T240:

I can see why Karl likes it!  

For info, here's the CFS Global Wind Oscillation (GWO) chart:

The current phase 6 position is likely to be a major influence on the bank holiday weather which is now pretty much pinned down by the models, followed I would suggest, by rinse and repeat....

[knocker]

Looking at the 5-10 EPS mean anomaly this evening it's relatively easy to see where the det. run is coming from. There is too much energy running south of the quite intense trough in the western Atlantic to allow the the subtropical high to ridge strongly. Once this starts to relax in the later period, , simultaneously with the trough over Europe. the subtropical gains more traction. For a while! So the assessment for the former period will be along the lines already posted.

NOAA is in the same ball park

Edited April 27, 2019 by knocker

[Frosty.]

There's a lot to like about the GEFS 12z mean and even out to mid may there is support for high pressure and warm weather.

Edited April 27, 2019 by Frosty.

[Leo97t]

Once again may is looking positive. It may not be until the autumn the current Dry spell breaks. I can see the next two months being unbelievably warm and dry and sunny. Loads to look foward to 

[Frosty.]

Really pleased with the GEFS / ECM 12z mean..more summery weather to come if they are right..well before summer arrives!!

[SunnyDazee]

Few hints that the second week of May will turn unsettled coming out of the GFS Parallel run especially. GFS operational dipping into unsettled and then straight out. Tuesday 7th of May looking like it could be a rough day though according to quite a few models. Looks to be back settled again by that weekend however