Model Output Discussion - heading into April

[shaky]

18z gfs about to join ecm?!!!looking good at 144 hours and a bit more blocked!!

[Allseasons-Si]

36 minutes ago, shaky said:

Icon 18z warm and dry to 120 hours!!fresh high ridging in from the atlantic/azores at 120 hours!!in line with ecm!!

Say Hi to the high

18z at 120 v's 12z at 126

i want this trend to continue in cancelling out that dreaded Scandi trough

1 hour ago, Man With Beard said:

So ECM has well and truly pushed unsettled weather to at least the end of the weekend, and very likely to see more days maxing between 20C and 24C towards the end of the week. 

Same old story - the models try to get a more unsettled pattern in place for next week - I suspect they may get closer to the mark this time as we are being attacked both from the west and east. 

this is always the case with the models MWB for unsettled weather to be forecast to then get pushed back everyday,i would happily take the GEM as this has been showing the same scenario for the last few days

looking at the latest cpc anomaly charts for both 6-10/8-14 days it appears to me like we have a stand-off between hp cell to the NE with trough to the west/northwest so not a cold direction,in fact if we get to day 8> it could be quiet pleasant

subsequent runs would/could tell the story soon,stay tuned and stay safe

think....,NHS,....applaud NHS,....thank NHS

now lets nip this virus in the bud in time for summer so we can get out and enjoy it

thanks

see you soon.

 

 

 

 

[Methuselah]

Mornin' all...Looks like the GEFS temperature ensembles are still holding up? All aboard for the Control run!

    

But, with crops being even more essential this year, what with COVID-19 and all that, a prolonged spell of very dry weather will not be a good thing, IMO...?

Edited April 21, 2020 by General Cluster

[Gowon]

16 minutes ago, General Cluster said:

Mornin' all...Looks like the GEFS temperature ensembles are still holding up? All aboard for the Control run!

    

But, with crops being even more essential this year, what with COVID-19 and all that, a prolonged spell of very dry weather, will not be a good thing, IMO...?

I don't know about anyone else, but I don't fancy living in a dust bowl.

Sunny and warm weather is bliss but we have to have rainy periods for life to exist, regardless of covid-19.

[Frosty.]

Looking at the Gfs 0z operational cloud / temperature maps for the rest of this week, it’s noticeable that there is a gradual increase in cloud cover but plenty of blue sky / sunshine too and temperatures continue to recover to rather warm levels for the time of year!!

 

Edited April 21, 2020 by JON SNOW

[johnholmes]

Another update on Tuesday 21 April using the 500 mb anomaly charts

Ec-gfs have, over the past 2 days changed to a chart showing troughing as the main feature affecting the uk., gfs was the first to show this pattern

Noaa is still undecided it seems 6-10 with both ridging and troughing close by? Possibly troughing being the main feature with  a flow at 500 mb off the atlantic? On ec and noaa that flow is quite slack but stronger with gfs.

If this is the right idea then, rather unusually, it will be the gfs 500 mb anomaly that led the way.

Looking at where the contours have originated the air is neither hot nor cold, so a rather typical somewhat changeable pattern for the 6-10 day outlook from now?

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

 

[Frosty.]

It’s interesting to note (to me anyway) that the ECM 0z ensemble mean is nothing like as gung-ho as the ECM 0z operational in introducing significantly colder more unsettled  troughy conditions beyond the current beautiful sunny spell, it does show a gradual decline in pressure from later this week but maintains some ridging for a while and would probably mean we end up with a sunshine and showers regime, some heavy and thundery with temperatures close to normal.

Edited April 21, 2020 by JON SNOW

[Frosty.]

Looking at the longer term GEFS 6z mean there are some hints that high pressure could be returning during early May following a more changeable / unsettled phase but despite the increasing risk of rain / showers beyond this week, the outlook may also include high pressure before some would think possible and also a chance we could import some continental warmth / humidity / thunderstorms...in the meantime, enjoy the continuing glorious sunshine!

 

 

 

Edited April 21, 2020 by JON SNOW

[Britneyfan]

Hopeful for a hot humid thundery spell during May! 

[Djdazzle]

1 hour ago, Britneyfan said:

Hopeful for a hot humid thundery spell during May! 

And a hot dry summer with a few thundery interludes. Not sure what the long range probabilities are looking like.

[mb018538]

4 minutes ago, Djdazzle said:

And a hot dry summer with a few thundery interludes. Not sure what the long range probabilities are looking like.

The April update is very sketchy and non committal. It has however gone back from favouring and drier and warmer summer from last months update to a more average picture. Maybe La Niña is a factor.

[Methuselah]

This afternoon's GFS 12Z looks okay, for next Tuesday; some places might get an utter deluge, whilst peeps only a few miles away, get nothing...That's the UK for you...?

    

At least it looks like those bone-chilling north-easterlies have hit the bin!

[Djdazzle]

1 hour ago, mb018538 said:

The April update is very sketchy and non committal. It has however gone back from favouring and drier and warmer summer from last months update to a more average picture. Maybe La Niña is a factor.

Thanks, was just asking out of interest - I have very little faith in LRF’s, especially ones which go for average and cover just about every base possible!

[B87]

1 hour ago, mb018538 said:

The April update is very sketchy and non committal. It has however gone back from favouring and drier and warmer summer from last months update to a more average picture. Maybe La Niña is a factor.

I thought it was going for troughing during summer and a generally poor season?

[mb018538]

6 minutes ago, B87 said:

I thought it was going for troughing during summer and a generally poor season?

It’s not showing one nor the other on the April update. As I said - the March update had low northern heights and stronger ones near the UK....as well as above average temps and below average ppn in the more likely category. Now they are all in the ‘neither yes or no’ category. Perhaps in May we will get a better picture.

[Singularity]

I've been checking out La Nina summers lately and haven't found any significant correlation with month-mean UK rainfall or temperature. In fact, there are some really warm, dry months to be found in the mix. Looks to me that it only increases the likelihood of seeing a particularly cool and unsettled spell of a 2-3 weeks within the season (tied into a large dive in AAM).

Onto the current modelling - I like how the GFS 12z dives next week's midweek would-be-invading Atlantic low well southwest of the UK and then broadly places us back into the warm easterly pattern we have in place as I write this .

 

South-tracking lows have had a habit of being adjusted Iberia-way in recent years, so it'd not surprise me to see something along these lines play out. I wonder whether increased Atlantic-Europe temp gradients, resulting from higher overland temps in W. Europe, are in some way 'attracting' travelling lows to this area? While that makes some sense for LP development, I'm not sure it does for LP paths relative to the area .

[Methuselah]

And, once again, the GEFS 12Z temperature ensembles hold up at mostly between 0 and +5C, which will do for me; 2m temps between, say, 12 and 17C are quite respectable, for April.

    

[mb018538]

Certainly looking like the Atlantic is going to break through early next week, with a long awaited return to westerlies, low pressure and some rain finally returning after a good 5 weeks off the scene. Some will be happy for a bit of a change!

[Geordiesnow]

43 minutes ago, mb018538 said:

Certainly looking like the Atlantic is going to break through early next week, with a long awaited return to westerlies, low pressure and some rain finally returning after a good 5 weeks off the scene. Some will be happy for a bit of a change!

I would not quite say certainty just yet, it's one of those where we may see some variation as the set up will go quite slack for the UK with pressure not too low but not too high either. Bit of a forecasters nightmare in terms of details I bet although increasing cloud amounts do look more certain. 

ECM has the Atlantic winning out but the differences at 144 hours are clear between the big 2 and subtle differencs either way could still alter the outlook. 

Has not rained here since overnight of the 5th into the 6th(that wet weather did not make it here on Saturday), I do hope any rainfall can hold off until the end of the month so potentially a record breaking dry month I would of thought. 

 

[stodge]

Evening All

MY usual suspects at T+240 off the 12z output:

That's GEM, ECM, GFS OP and GFS Control respectively.

Not much agreement there it would seem so the journey from the breakdown of the current regime to the end of the month far from resolved.

[mb018538]

29 minutes ago, Geordiesnow said:

I would not quite say certainty just yet, it's one of those where we may see some variation as the set up will go quite slack for the UK with pressure not too low but not too high either. Bit of a forecasters nightmare in terms of details I bet although increasing cloud amounts do look more certain. 

ECM has the Atlantic winning out but the differences at 144 hours are clear between the big 2 and subtle differencs either way could still alter the outlook. 

Has not rained here since overnight of the 5th into the 6th(that wet weather did not make it here on Saturday), I do hope any rainfall can hold off until the end of the month so potentially a record breaking dry month I would of thought. 

 

Could be - ecm is a rotten unsettled outlier; so will probably be somewhere between the two in reality.

[I remember Atlantic 252]

12 hours ago, mb018538 said:

Certainly looking like the Atlantic is going to break through early next week, with a long awaited return to westerlies, low pressure and some rain finally returning after a good 5 weeks off the scene. Some will be happy for a bit of a change!

Aye, westerlies unusual between April and June

[Methuselah]

So, the westerlies are about to take control. But what's next? This? We can but hope!

    

The GFS 00Z at T+384: To trust or not to trust? That is the question!

The man from the ensembles, he say 'nyet'!

    

[Methuselah]

Might be some tasty convection around, next Tuesday, should this GFS 06Z verify; light winds, cold 850s and SLPs of around 1008mb?

    

Edited April 22, 2020 by General Cluster

[Methuselah]

Ne'er cast a cloot till May is oot!

    

FWIW, my guess as to why we've nae seen a patch of North Sea filth this year is that, as we've not seen a single significant cold spell since March 2018, the upper layers of the North Sea should be warmer and deeper than is usual, at this time of year...?