Model output discussion 14/04/18

[damianslaw]

May tomorrow, and for the north, often the start of the three month summer (tends to go downhill when August arrives..). Lots of high pressure shown in the models this evening from the 4th onwards, and growing steadily warmer, and dry for most away from the far NW. By May high pressure overhead can quickly create homegrown warm pools which build in situ especially when there is limited cloud and wind - many a May this has happened and temps have nudged in the mid 20's quite easily, indeed in some years, here in the Lake District we can see our warmest and driest weather of the year in May (2012 for example). It can be a fantastic month in these parts - far far far better than August in my book!

Looking back at yesteryear we've had some glorious sustained summery weather in Mays gone by, early 1990, much of 1992, 1995, 1998 - a 2 week sun warm fest, ditto May 2006 and 2008, late May 2012 was excellent, however, recent Mays have been quite dissapointing for sustained warm dry sunny weather. Could 2018 buck the trend of recent years?

My forecast in the CET thread is for quite a lengthy warm period earlier on in the month, perhaps lasting up to 10 days or so generally, but then heights advect west and we drag in cooler NW airstream for the second half - high pressure does have a habit in May of moving to more northerly climes, but it also has a habit of sticking arounf for quite some time - with the atlantic in its deep annual sleep - it tends to stir as we enter June.

[MP-R]

Looks like a rapid improvement from Thursday onwards for at least a week, divergence thereafter with all plethora of options on the table. GFS in particular often puts the UK between low pressure to the NW and SE and high pressure to the NE and SW with budges here and there. I like May for its variety and the fact that any one weather pattern doesn't tend to last that long. From your list @damianslaw, 2016 and 2012 fit that bill with 2016 in particular switching from a cold start to warm to thundery to very wet to chilly to showery to warm again. Hopefully a varied May to come, and most importantly, sunshine levels look like going up considerably (not hard!)

 

[Fourty Point Three Degrees]

 GFS is not too far behind the ECM on keeping LP away for some beautiful fresh early May sunshine. Temps could easily pick up and reach high 20's if those charts come off. Looks like Springtime is here at last  

Edited April 30, 2018 by 38.5*C

[mb018538]

Ukmo with a slight wobble this morning and not bringing in the warmer air, on its own though as all other models stay with the settled and warmer theme. Hopefully it will correct back later on the 12z. Looking forward to a great bank holiday weekend.

[bluearmy]

Even the ec46 is warmer than previous runs have been ! 

Could be a broadly pleasant  May on the cards .........

[Summer Sun]

30 minutes ago, mb018538 said:

Ukmo with a slight wobble this morning and not bringing in the warmer air, on its own though as all other models stay with the settled and warmer theme. Hopefully it will correct back later on the 12z. Looking forward to a great bank holiday weekend.

It's only t144 which has some slightly fresher air before then it has warm air 

 

[Summer Sun]

The trend is most certainly our friend at the moment looks warm and settled for quite a while once the high arrives

 

[Summer Sun]

ECM monthly right for April final assessment left

[Summer Sun]

UKMO t168 shows the high in no rush to leave

[Summer Sun]

00z GEM shows it turning progressively warmer through its run

Long may it continue

Edited May 1, 2018 by Summer Sun

[Skyraker]

I'll have a bit if that, it's bloody orrible out.

[Frosty.]

Really nice looking GEFS 00z mean both for the BH weekend and longer term out to mid may and potentially beyond, very little sign of cool atlantic dross indicated apart from the far northwest at times, mostly it looks settled and warm with high pressure either over or close to the uk..for the southern half of the uk it's looking very good..fingers crossed!?

[NO LONGER POSTING]

Summer sun.. It's time for you to shine again lol! 

Some Stella charts this moring for early summer/late spring 

One thing I will say is the cold air further north has been very reluctant to go back to where it belongs.. 

[mb018538]

That's what we like to see...6/7 days above average with no ppn spikes, and the mean staying above the average all run too.

Edited May 1, 2018 by mb018538

[stodge]

Morning all

After yesterday's winter-like day in lowland East London, we start a new month with a considerable improvement - the Sun out and the temperatures on the up. The weekend ahead looks set fair which will please many but where do we go from there ? Plenty of possibilities yesterday and let's move to the end of next week, Friday May 11th, for this morning's medium term model analysis

Starting as always with the ECM 00Z OP for T+240:

Reminiscent of yesterday's 00Z GFS OP - the first HP for the weekend declines but new heights build to the north and north east of the British isles so by T+240 it's generally settled but with a cool NE'ly breeze across southern parts. The next LP is negatively tilted and it would be fascinating to see if it would dive SE to the west of Ireland (as GFS OP did yesterday)..

On then to GEM 00Z at the same time:

GEM was very anticyclonic yesterday and remains so today but as yesterday a hint of change at the end of the run and as yesterday it's worth looking south as the trough develops over France and, combined with falling heights to the west, my view would be the warm settled outlook would degrade to showers and something much less settled. Let's see if the trend continues through tomorrow.

GFS 00Z OP at T+240:

An increasingly unsettled outlook as LP has moved down from the west of Iceland to be just off North West Scotland with frontal bands crossing the country albeit with only light rain for the south east. Further into FI and the unsettled picture continues with LP close to the north-west of much of the run.

GFS 00Z Control at the same time:

Not a million miles from the OP but with a more intense LP close to western Britain so rain and strong winds for Ireland. Further into FI and the LP disrupts to the north west as heights build again to the north as was a feature of 00Z low-res yesterday.

The 00Z GEFS at T+240:

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240

While the OP and Control scenarios aren't without support in the suite the majority call is to retain the anticyclonic domination with HP close to or to the north east of the British Isles more aligned to the ECM solution. Further into FI and the strong signal for northern blocking remains undiminished with HP close to or to the north of the British Isles across the ensemble members.

In summary, fine weather for the Bank Holiday and continuing through next week on the models but a hint of a change at the end of next week with LP encroaching from the NW or south and heights falling to the west suggesting a more thundery and wet outlook for many. This looks short-lived for the north with HP returning by mid month but the south remains potentially warm and unsettled with the risk of thundery showers or rain.

Today's bonus chart comes from T+5736:

Fine and frosty for the British Isles with, as usual, the coldest air just missing us and a white Christmas for the south of France.

[Fourty Point Three Degrees]

ECM backing off a little today on the ECM0z as far as warmth is concerned as high 850s only get into the south for just one day only next Sunday.

[Frosty.]

31 minutes ago, 38.5*C said:

ECM backing off a little today on the ECM0z as far as warmth is concerned as high 850s only get into the south for just one day only next Sunday.

The Ecm 00z ensemble mean looks fantastic for those of us who love high pressure and warmth..it goes on..and on..and on!?

[Man With Beard]

EC clusters for mid-May - probabilities good for heights either over the UK or to the east - above average conditions looking to continue for a while if that pans out.

Edited May 1, 2018 by Man With Beard

[Frosty.]

The GEFS 6z mean looks great for the BH weekend with temperatures into the low 20's celsius widely across england and wales under high pressure..there's also good support for the extended fine / warm spell shown on the Ecm 00z ensemble mean from the latest update from exeter for a summery outlook with plenty of settled sunny weather and well above average temperatures and also a chance of more humid / continental inflow with thundery showers from time to time...may is looking potentially really good, especially across the southern half of the uk.

[Summer Sun]

UKMO get's the 12z's off to a fine start

 

[Summer Sun]

GEM is brilliant for some prolonged warmth

Hope it's right

 

[I remember Atlantic 252]

20 minutes ago, Summer Sun said:

GEM is brilliant for some prolonged warmth

Hope it's right

 

Hope so, because GFS looks pants, setup more typical of Dec/Jan, than May

[SizzlingHeat]

GFS shows a fairly decent bank holiday weekend then much more unsettled again for next week into the following weekend. Seems to be disagreement between some of the main models at the moment so wouldnt be surprised if the 12z was a cool outlier for next week. Although the 6z showed a similar evolution so one to watch would be the ECM this eve to see if it's an increasing trend. Temps for weekend according to GFS ranging from 18c in the north to between 18 and 24c in the south. Perhaps close to 27c on Monday itself, but much cooler by midweek.

GFS also showing a fair amount of cloud with the sunniest skies on Sunday across England and Wales with some heavy thundery showers possible on Monday in south as pressure falls.

[mb018538]

It should be noted Ukmo is again much cooler than gfs, with he warmest 850s staying into France. Plenty to be sorted out yet!

[Frosty.]

7 minutes ago, mb018538 said:

It should be noted Ukmo is again much cooler than gfs, with the warmest 850s staying into France.

It still looks great though with high pressure becoming dominant and pleasantly warm in the strong early may sunshine..i.e..perfect BH weather for most of the uk!?

Edited May 1, 2018 by Frosty.