Model output discussion 14/04/18

[Mike Poole]

ECM at T240

Edited May 12, 2018 by Mike Poole

[damianslaw]

Quiet times at the moment - I've not been paying much attention to the models in recent days, no expectation of anything especially notable on the cards in terms of cold, warm, or wetness or dryness. Just very typical May weather, which usually means generally very pleasant and on the drier side of the yearly norm - given the atlantic is now firmly in its annual deep sleep stage. So not surprising to see signal for heights to build over the UK in the days ahead, with temporary interruption from the NW mid week and perhaps becoming warm for all by next weekend again (high teens - mid 20's maxes).

There is a suggestion the atlantic trough will sharpen quite a bit next week, how this then interacts with projected height development over and to our NE will determine fortunes for the second half of the month - will it be forced to go under and we then see heights transfer to our north and north west - quite normal for May, or will it split with energy going north and south under what would be a blocking high - again quite normal for May. Either way I'm foreseeing quite a lengthy pleasant dry period ahead, with any precipitation on the light shortlived side. If this was July and August, I wouldn't be so certain.. but given its May then the odds are much higher - given the suppressed state of the jet at this time of year.

[Frosty.]

Overall i'm pleased with the Ecm 12z and indeed the models generally which have continued to improve our weather prospects during the last few days for next week and further ahead..could be plenty of pleasant weather to look forward to as we approach the end of the meteorological spring..a few cold nights later next week but apart from that it's looking very decent for most of the time.

[Frosty.]

I think most will agree tonight's Ecm 12z ensemble mean is showing a predominantly pleasant outlook for much of the uk with sunny spells and it's only really the far w / nw which are occasionally a bit more unsettled but for the majority it looks pretty decent for late spring with plenty of high pressure / ridging influence.

[Summer Sun]

00z UKMO is another great run for settled weather

[Summer Sun]

Looking at the 00z central Europe is going to see a lot of rain over the next 10 days whilst the UK gets lucky and sees very little

[bluearmy]

3 consec eps cluster runs have now failed from Icelandic metoffice site. Hope it’s just a data glitch. 

[johnholmes]

What else might it be blue?

Turning to the 6-10 day outlook with the usual 3 500 mb anomaly charts as guide.

This is a copy of my notes having studied them this morning.

Sunday 13 may

Ec-gfs shows ec more trough, little signal for ridging anywhere near uk; gfs still has ridging as its main feature over/close to e of uk

Noaa also is trough orientated in uk area for 6-10 although the signal is less definite than ec. Indeed the 8-14 has just a suggestion of a bit more ridging being possible. Hard to know if this is a trend or not

Overall the 6-10 day upper flow looks to be from a fairly strong atlantic flow into a much less strong south of west flow over the UK.

Thus more unsettled than settled in this period but not a wash out by a long way. Looking like the oft seen NW-SE split, best the further SE one lives?

and the charts, see below

http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

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

[Mike Poole]

Early doors on the 12s and the models look really great for developing an anticyclonic spell for the UK.  The weather not that shabby at the moment for most, but the high taking hold by about Thursday.  No explosive heat yet, but it's good to see in advance of the summer months. 
ICON done so here's the GIF, nice run this:

GFS at T114:

GEM at T132:

UKMO at T144:

[Frosty.]

It's a pretty good week coming up with plenty of sunshine and warm tomorrow and especially tuesday when temps will be into the low 20's celsius across southern uk. The midweek period wed / thurs will be cooler but still largely fine with sunny spells but a few cold nights with mist / fog patches and a risk of slight rural frosts but then warming up again through fri and even warmer next weekend with temps back into the 20's celsius, this is based on the Gfs 12z but I should say the icon 12z looks great towards and during next weekend too.

[Singularity]

Hopefully ECM will finally come around to having enough of an amplifying trough out west to build a decent ridge across the UK during the weekend, rather than something messier with smaller troughs sneaking across and taking apart the nicer weather for many and then all (SE escaped until late on the 00z).

 

Way outside the reliable, but that sure is a peculiar looking final few charts from the GFS 12, with very warm or even quite hot conditions well-established all the way up through Scandinavia and edging gradually toward us while a hurricane runs up the U.S. East Coast. More like early September than late May! 

[Frosty.]

Plenty of high pressure / ridging on the Ecm 12z for the week ahead, warm early, cooler blip midweek period and then warming up again. A good week of largely pleasant weather with sunny spells, some patchy cloud midweek as a very weak cold front slides SE and introduces cooler / fresher north atlantic air briefly.

[Frosty.]

One thing that could be improved is giving more time to edit / improve a post but at least the 12z model output is looking predominantly fine for most of the uk during the next 7-10 days.

[mb018538]

It’s a bit neither here nor there. Happy that it’s staying mostly settled, may be a bit cloudy at times, but better than a washout. Looks like lots of model uncertainty still around.

[ANYWEATHER]

26 minutes ago, mb018538 said:

It’s a bit neither here nor there. Happy that it’s staying mostly settled, may be a bit cloudy at times, but better than a washout. Looks like lots of model uncertainty still around.

Indeed as far as the weekend is concerned gfs and ecm differ greatly , but looking like a half decent week for most with little rain for the majority , and some chilly nights coming up with potential frosts ,so gardeners beware , Gentle Weather coming up......

[Singularity]

Not pleased with ECM keeping more Atlantic influence for the northwest this weekend. You can probably guess why!

It really has been the nuisance model in recent days - and was also this way quite a bit over the winter, with a habit of handling troughs in a very different way to the other models at just 4-5 days range. It has a mixed scoreline from that in terms of wins and losses which means this behaviour only adds to the uncertainty.

[Man With Beard]

I'd say the outlook is good, but not great, because ridging just doesn't look sure what it wants to do. Should be a pretty good week this week without being particularly hot, beyond that though ridging looks like it could escape quite easily into a position conducive to heat or to something less settled. But quite a few May's I can think of where I'd have snapped your hand off for the current position. 

[Fourty Point Three Degrees]

GFS 18z is a quite a dry and pleasant run, lots of HP around nothing too hot or humid.  There is the threat of some rain but nothing to scream about.. Over in FI things get serious with a nice ridging of the Azores getting splattered right across the UK.   

[Summer Sun]

High pressure in charge on 00z UKMO

[summer blizzard]

Quite a subdued pattern on the horizon..

Out to about 6 and high pressure over the UK should deliver maxima around 20C with more or less clear skies (the good thing the lack of a southerly component should produce cool nights)..

After about day 6 both the GFS and Euro do agree on a progressive breakdown but it looks slow so i suspect we'll just see a lot of cloud before the low finally pushes through. 

[Singularity]

If we could get the trough disrupting nicely to start next week with a low drifting by SW of the UK, there's support from the MJO for the Scandinavian High to stick around close enough to keep us generally fine and on the warm side for quite a while.

ECM's improved with this on the 00z but remains the least enthusiastic model, GFS 00z is just about there but things turn a bit too slack for my liking, while GEM 00z does a fine job indeed.
UKMO 00z is closer to GEM 00z than the other two at +144, which is encouraging.

  

[JoeShmoe]

Loving this weather at the moment , 18-22c, warm sun, blue skies, not too hot

Perfect early summer weather !

[Mike Poole]

Few charts from the 12s, there is some interest here.  GFS first, at T108, high pressure into Saturday.  Reasonable evolution after that and then a big 1040 high at T276, obviously unlikely at this stage but one to watch, rest of run really good too.

GEM at T240:

UKMO at T144:

Not much sign of the Atlantic on any of this!

Edited May 14, 2018 by Mike Poole

[Mike Poole]

Switching to long range models, the May GloSea5 charts are out for Jun, Jul, Aug,  check these out!

500mb heights:

2m temperature outer quintiles, I think this is the strongest signal for a good summer I have seen on these since I started watching them.

Precipitation outer quintiles, signal less strong, but pointing towards drier.

[Mike Poole]

Not much to add re the earlier timeframe from ECM, here's the T240 from the op and the ensemble mean:

Looking good for the continuation of settled weather into the medium term. Low spread/standard deviation/uncertainty on the ensembles for the south at T240, the uncertainty to the north associated with the jet stream, will the northerly jet persist into summer? Hope so.

Edited May 14, 2018 by Mike Poole