Model Output Discussion 31/03/14 onwards.

[knocker]

Certainly looking at getting some colder air at the end of next week with high pressure to the north with associated ridge over the UK.

 

[Milhouse]

A couple of fine days seem to have popped up recently on the models for Monday and Tuesday next week under a ridge of high pressure.

 

[Geordiesnow]

A couple of fine days seem to have popped up recently on the models for Monday and Tuesday next week under a ridge of high pressure.

 

 

Indeed although Tuesday could look cloudier and wetter for Northern areas as a cold front heads down from the North but I think the detail is far from certain and until we know how things develop during the next few days then next weeks forecast is far from certain. 

 

I do see the potential of something colder(for the time of year) to occur but I can just see the chances of it being a waterdown slackish northerly flow from the North, it always seem to be the case with Northerlies nowadays but the models do appear to be struggling on how the pattern will develop but the advantages of a stronger Northerly is it will push away any low pressure systems with its weather fronts away from the UK and it leaves a brighter more convective outlook but I would not be surprised if its a weak slack flow and the South sees a lot of heavy rain from a stalling low pressure system. 

 

It was a bit surprising though too see some warmth appearing for Monday and Tuesday though but I would not bank on it staying like that just yet. 

[Summer Sun]

New version of GFS released from Meteociel it enables you to see pressure, 850 temps, jet stream and precipitation in 3D, click anim for a smooth animation the new version runs to t180

 

http://meteociel.fr/modeles/gfse_3d.php?mode=1

[knocker]

Cold spell?

Edited April 24, 2014 by knocker

[johnholmes]

I think the odds are that this northerly outbreak will be too watered-down to bring widespread snow showers- the main factors being a strong build of pressure to the north and north-west, and troughs moving from west to east across the south, introducing more of an easterly flow.  Most model outputs are going for a weak ridge of high pressure into the first week of May, with dry sunny weather and some night frosts for the north and west of the country although the east and south of England may be more prone to cloud and belts of rain.

 

The NOAA 8-14 day updates and ECMWF ensemble mean are suggesting that an Atlantic trough may drift eastwards during the first week and produce warmer and more changeable conditions later in the first week of May:

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

I assume you mean west not east!

move east and we stay on the cold side of a trough, west, as the chart shows you quote and it means the upper air is sourced from a more southerly point?

[Barry12]

It's nearly May, it's not going to snow!

[Polar Maritime]

It's nearly May, it's not going to snow!

 

Well it can and has done before, We have even seen Snow in June round these parts..

 

http://www.buxtonadvertiser.co.uk/news/local/dickie-bird-recalls-when-snow-stopped-play-in-buxton-1-3493083

[phil nw.]

I wouldn't rule out Scottish snow especially higher up but latest ens means seem to suggest the cold plunge around midweek runs out of steam as it comes further south although still feeling chilly for a couple of days.

 

http://www.wetterzentrale.de/pics/Reem1682.gif

http://www.wetterzentrale.de/pics/Rt850m7.gif

 

by the following weekend a chance of the Azores high making a move this way-ECM mean run a little more bullish on this.

http://www.wetterzentrale.de/pics/Reem2161.gif

Could well be a nice start to May.

[Summer Sun]

Before we get to any cooler snap next week starts on a warm note for many though we'll still have some rain around for some

 

 

By Wednesday it turns colder in Scotland but it remains warm for England and Wales with the highest temperatures probably towards London and the SE

 

 

By Thursday temperature tumble for all but the far south though ever here they'll be down on the previous days

 

 

Continued signals again this afternoon for a rise in pressure later next week though temperatures will still be lower than average initially

 

Edited April 24, 2014 by Summer Sun

[Captain Shortwave]

More delays on the cold snap with the models starting to agree on  Thursday being the moment where cold air spreads south across the UK. By Friday it looks like high pressure will start to move back in from the west. 

As stated by a few others, we have quite a warm airmass to start next week, could be quite warm in places if there is any decent spells of sunshine.

[Summer Sun]

ECM following the rest in giving us a warm start to next week especially so in any lengthy spells of sunshine midweek sees some cooler air just coming into northern Scotland but the south holds onto the warmest air for another day

 

 

Beyond the cold snap the GFS ensemble is showing a rise in pressure just in time for the BH weekend

 

Edited April 24, 2014 by Summer Sun

[Milhouse]

And on the other side of the colder spell the 12z ENS mean has high pressure likely to be back over the UK by next weekend

 

[ANYWEATHER]

Looks a pretty darn cold spell for the latter end of next week but as its so far away many changes to come, although models are hinting of some sort of cold shot :winky:

[Summer Sun]

Although starting with lower than normal temps all signs currently are a rise in pressure later next week

 

Edited April 24, 2014 by Summer Sun

[Winter Cold]

Well tonight its the 2nd of May which is looking interesting for those like me who would enjoy something unusual

 

[Milhouse]

Bank Holiday weekend looking good on the ECM 12z, Although starting off rather chilly.

 

 

[Captain Shortwave]

Well tonight its the 2nd of May which is looking interesting for those like me who would enjoy something unusual

 

The issue at this time of year is that despite cold looking 850s, the daytime temperatures will still reach double figures for many. Looks like a few frosty nights but that's all, the speed the models are trying to bring high pressure back in then convective potential looks limited. Still the bank holiday weekend could be pretty bright and sunny if a little chilly if the models are handling this half decently.

[ANYWEATHER]

The issue at this time of year is that despite cold looking 850s, the daytime temperatures will still reach double figures for many. Looks like a few frosty nights but that's all, the speed the models are trying to bring high pressure back in then convective potential looks limited. Still the bank holiday weekend could be pretty bright and sunny if a little chilly if the models are handling this half decently.

Yes indeed! despite chilly air it will feel very warm in the strong spring sunshine.....lovely    

[damianslaw]

The issue at this time of year is that despite cold looking 850s, the daytime temperatures will still reach double figures for many. Looks like a few frosty nights but that's all, the speed the models are trying to bring high pressure back in then convective potential looks limited. Still the bank holiday weekend could be pretty bright and sunny if a little chilly if the models are handling this half decently.

 

Cold uppers can produce preety chilly temperatures well into May under a cloudy/wet sky. Early May 97 brought very low maxima with most places struggling to hit 10 degrees on 6th May and over northern half of the country temps barely scraped 5-6 degrees. May is a deceptive month. I remember May 96 all too well. days and days of maxima in 7-10 degrees thanks to winds off a cold N Sea - uppers were not that cold.

 

Northerlies at this time of year generally mean significant convection thanks to the strong sun, temps climb in the sun but fall rapidly under showers. Double figures certainly not a guarantee.

 

This time of year is peak time for northerlies as well.

[Summer Sun]

ECM ensemble showing a nice rise in pressure later next week and into the weekend with temperatures slowly recovering after the cold snap

 

[Captain Shortwave]

Cold uppers can produce preety chilly temperatures well into May under a cloudy/wet sky. Early May 97 brought very low maxima with most places struggling to hit 10 degrees on 6th May and over northern half of the country temps barely scraped 5-6 degrees. May is a deceptive month. I remember May 96 all too well. days and days of maxima in 7-10 degrees thanks to winds off a cold N Sea - uppers were not that cold.

 

Northerlies at this time of year generally mean significant convection thanks to the strong sun, temps climb in the sun but fall rapidly under showers. Double figures certainly not a guarantee.

 

This time of year is peak time for northerlies as well.

The trouble is the convective window for this northerly occurs on Thursday night, by Friday we already have the UK under high pressure building in from the Azores

On Thursday the north might get some showers but the south will be under a cold front so just general rain there. Given the cool airmass I suspect sunshine amounts will be pretty high and allow temperatures to recover from near freezing to get to around 10-12C, but rising as we head through the weekend.

[ANYWEATHER]

The trouble is the convective window for this northerly occurs on Thursday night, by Friday we already have the UK under high pressure building in from the Azores

On Thursday the north might get some showers but the south will be under a cold front so just general rain there. Given the cool airmass I suspect sunshine amounts will be pretty high and allow temperatures to recover from near freezing to get to around 10-12C, but rising as we head through the weekend.

A long way off, things will definitely change.....

[draztik]

A two day 'cool' spell next week, before a return to warm spring sunshine with high pressure dominating - so says the ext ecm ens & gefs. CFS ens now showing a mild/warm May. So, another cool period has been reduced to a day or 2.

[knocker]

The holiday weekend with the ECM. Okay but not that warm.

 

Edited April 24, 2014 by knocker