Model Output Discussion - Heading Away From Easter

[Thundery wintry showers]

Indeed, on the ECMWF run (both operational and ensemble mean) the Atlantic trough gets north of 55N and so we don't end up stuck in a persistently overcast south-easterly type, like the one around the 6th-10th March, with slow-moving fronts, cool days and warm nights. Instead, slow-moving fronts would probably end up largely confined to northern Scotland with the rest of us having some bright and showery polar maritime or returning polar maritime interludes in between the rain belts.

This morning's ECMWF run showed the jet stream further south than tonight's run, which may have translated to a more persistently cloudy and wet regime IMHO.

Although a change to less cold and more unsettled weather looks highly probable, it's hard to say exactly how the surface weather associated with it will pan out. The GFS and UKMO are not dissimilar to the ECMWF at T+144 but the GFS subsequently has high pressure establishing to the east giving us those warm southerlies, but I don't trust those at that sort of time range. I think, though, that a persistently dull wet regime is probably no more likely than a full-on southerly, and that the most likely outcome is somewhere in between.

Edited April 1, 2013 by Thundery wintry showers

[Carlrg]

I hope the Honey and Bumblebees get a chance this year. Last years rain decimated their colonies and another wet year would really put them on the brink. The honey bees were struggling with the Veroa mite already and the wet weather must have been the final straw. We desperately need some decent charts like this to start verifying.

Lovely output.

[Mark Neal.]

Unsettled weather for the UK, less cold however but wet... But look our old friend the azores high is waiting to pounce :-)

[Cheshire Freeze]

Got to love the GFS. From late spring warmth to a winter blast in the space of 6 hours between runs.

Edited April 1, 2013 by CreweCold

[Mark Neal.]

Interestingly, just what i was refering to, look at the high as that system exits the uk, slowly. We pull up a high pressure and builds over us...

- From this.....

to this...

So as a weather system heads into the UK, high tries to sneak northwards in behind... Well thats the GFS 18z run lol

But the high has us on a bitter easterly side, with some cold air coming our way again, it is the GFS and the pub run though..

Edited April 1, 2013 by Mark Neal.

[bluearmy]

stage 1 was always to lose the deep cold wrt normal. that now seems a reasonable call as we head towards mid month. question now becomes - settled, changeable or unsettled ???

[Cheshire Freeze]

stage 1 was always to lose the deep cold wrt normal. that now seems a reasonable call as we head towards mid month. question now becomes - settled, changeable or unsettled ???

Or back to cold ala 18z......lol

[Mark Neal.]

stage 1 was always to lose the deep cold wrt normal. that now seems a reasonable call as we head towards mid month. question now becomes - settled, changeable or unsettled ???

Yes, i would say perhaps a cold unsettled outlook is possible like the ECM keeps showing with that system heading our way and lingering. But with some settled weather thereafter... Or The azores high ridges to give us some spring warmth, though still some chilly nights as you would expect for spring.. like other model runs have hinted over last few days.. Definitely going for the less cold scenario, but like you said, unsettled & cool? Warmer, settled?

[Mark Neal.]

So the GFS has thrown up a cold easterly for midmonth on the GFS 18Z run as Crewe.Cold has said...

[Purga]

After a brief mild spell a familiar setup re-establishes

v

Maybe some snow as well

Fascinating period this Spring if this were to verify.

[Peejayem]

Yep, 300+ hours on the GFS 18z is always a sure thing to verify

[SE Blizzards]

-10 uppers in parts of N England and EA in the middle of April? Is that even possible?

[Robbie Garrett]

Be interesting to see how this high pressure, northern blocking pans out this Summer. Because sooner or later that cold feed from the east/north east will get warmer and if it links up with a continental feed from Russia, maybe quite warm.

[Guest pjl20101]

Got to love the GFS. From late spring warmth to a winter blast in the space of 6 hours between runs.

That should be removed CreweCold by tomorrow or even Wednesday as its not in line with the NOAA output in 6-10 days time or 8-14 days time.

[rory o gorman]

The cold blast deep in F.I is a deep outliner, a bit of straw clutching going on tonight it seems .

[Argyle1980]

Deep into FI but after a long winter this is just what we have been looking for.

[SLEETY]

yep,looks like its game over for this amazing cold-spell this morning as the Atlantic finally breaks through at the weekend and temps slowly recover.Cant even remember the last time it hit double figures.

Looking unsettled as well unfortunately

[Weather-history]

ECM doesn't look that pleasant later to be honest. Milder compared to recently but it still looks coolish to average with rain around and breezy in places. UKMO seems to hang the low further to the west.

[mushymanrob]

All those looking for relatively milder weather, be careful what you wish for because the Ecm 12z turns into a very unsettled run with spells of wet and windy weather although temps do recover but not especially mild.

doesnt matter who wishes for what mate, nature will do what nature will do regardless of peoples wishes!

well, when carole kirkwood on bbc breakfast predicts a likelyhood of the cold going by early next week, it must be becoming a believable scenario now. the bbc never stick their neck out unless theres some certainty. interestingly now the anomaly charts are firming up on pattern change then im far less scepticle as i have been.

nope, it wont be especially mild at first, but a major switch from very cold to mild within a few hours (day) wasnt realistic. but to get to mild/average, theres always going to be a transition with less cold and unsettled.

but we still have several raw days of pretty dead weather, we might even lose the sun, the sooner we are out of this freezer and can start to enjoy normal spring weather, the better.

[Purga]

ENS showing the change quite markedly to warmer weather

But - the Op again is a very mild solution compared to most runs and after the 14th the mean starts to decline again with the control taking a definite plunge downwards.

So a brief but pretty certain warm up from early next week followed by more uncertainty and a possible return of colder conditions.

Edited April 2, 2013 by Purga

[johnholmes]

as promised, my view on a pattern change

Pattern change prediction-2 April 2013.pdf

[The PIT]

Definite warming up trend but then there should be anyway. Although ECM never shows anything warm average will feel like a heatwave right now.

As for presenters making predictions sometimes they simply don't look at the models and you take what they say with a pinch of salt. One of them predicted spring right at the beginning of this cold spell. Had me going through every model run too see where she got idea from and she'd simply dreamt it as nothing supported her idea. Needless to say she didn't mention it the next day. Can't remember who it was one of the new ones.

[Gibby]

Good morning. Here is the latest report from the 00z outputs of GFS, UKMO, GEM and ECM for today Tuesday April 2nd 2013.

All models show the next 3-4 days with very little change over the UK as High pressure continues to lie to the north of Britain with a cold East or NE flow across the UK, strong in the South. Dry weather would largely be maintained apart from the odd wintry flurry near the East Coast and in SE England. The weather will stay cold with widespread night frost. A weak front pushing South across Scotland by the weekend could bring a little rain and hill snow here. It is then that a pattern change starts to develop over the British isles.

GFS shows a collapsing ridge of High pressure move SE over the UK on Sunday with another fine and less cold day for most followed by a trough of Low pressure moving East on Monday with rain at times followed by clearer and drier conditions on Tuesday. All the time temperatures will be recovering to nearer the normal especially from midweek when SW winds really take hold bringing spells of wind and rain East across all areas, heaviest in the North before a return of showery or dry weather by the weekend, driest in the SE. Through the rest of FI today the model shows a North/South split developing with bright, dry and possibly quite warm conditions affecting the South in association with high pressure close to the SE while the North sees more in the way of cloud with rain or drizzle at times. frosts would become unlikely in this pattern.

The GFS Ensembles are in strong support of milder air developing across all areas though the warmth shown in the South by the operational run is not well supported. Nevertheless, the general theme of the removal of the cold East wind in preference to mild SW winds is a strong one though there is no strong indication of substantial rainfall anywhere so it might be that High pressure remains close by enough to ward off any active troughs.

The Jet Stream confirms the warm up moving much further north over the next few days to a position over the Atlantic at around 50-55deg N in a heading for the UK by the end of the reliable time period.

UKMO this morning shows a ridge of High pressure over the UK on Sunday gradually being replaced by a trough of Low pressure easing in from the West. The removal of the colder air would be rather slower in this pattern though rain should be well into Western and Central areas by Monday with just the East hanging on to the dry and chilly weather.

GEM too has a rather slow move towards milder weather early next week which isn't really set in until Tuesday and Wednesday when mild air makes it right through the UK with troughs bringing breezy weather with rain at times and temperatures much closer to the April average.

ECM today remains the most boisterous in it's transgression from cold to mild beginning the process on Sunday with a trough and some rain moving slowly East through Britain followed by a more vigorous spell of weather before midweek as a deep and vigorous Low moves slowly East and NE across the UK with Southerly gales and heavy rain followed by squally showers as we move into the latter stages of the week and the weekend that follows. It would be markedly less cold than currently though despite the rain.

In Summary the weather is set to change. We have several more days of what we have become accustomed too in the shape of cold and dry conditions with the nagging NE breeze continuing in the south for some time yet as well as sharp overnight frosts. The wind eases by the weekend though and a dry couple of days seem likely with less cold feeling conditions. Next week then shows the Jet having moved north and low pressure areas steered towards or to the north of the UK bringing troughs steadily NE over Great Britain with rain and strong winds. The more sedate nature of delivering this shown by GEM and GFS would be the preferred transition type whereas the ECM model would deliver a much more inclement period of wet and stormy conditions from midweek next week albeit sharing the less cold air that the other models show. the saving grace for farmers and growers will be the less likelihood of frost once we move out of the coming weekend.

[Summer Sun]

GFS holds firm again this morning with low pressure where it should be north and high pressure building from the south controlling our weather

A lot milder as well

ECM is still having non of it this morning but the GFS ensembles are showing a clear warm up next week again

[Summer Sun]

Based on the Latest NAO its goodbye and good riddance to northern blocking next week