Model Output Discussion - 15th April Onwards

[Polar Maritime]

Becoming a little warmer in South next week, with temps probably rising to something around average or just above. While the North stays on the cooler side hovering average or just below. Easterly winds blowing off the North sea will make it feel cooler under any cloud cover, but also pleasant in any sunny spells where temps could hit 16/17 in the far South. The North will struggle to reach 12/13c with frosts at night where the clouds clear.

Again the South is looking much wetter than the North next week, which is good news for the these dry areas which need the rain, while the North will have showers, these falling as sleet/snow over the Highlands.

As shown by this chart, the slightly warmer uppers only just touching the far S/E.

As ANYWEATHER has just said "unsettled" sums it up. And feeling cool.

Edited April 26, 2012 by Polar Maritime

[Nick F]

00z ECM rather at odds with GFS and UKMO this morning wrt to the deepening low moving north over western France/BoB on Sunday. ECM moves the low over southern England, while GFS and UKMO pull it NW then eventually west.

Seems to stem from the position of the upper trough this weekend and how it disrupts into a cut-off low which in turn effects the position and track of the low deepening over western France. GFS and UKMO much more progressive than ECM in disrupting the trough into a cut-off upper low which sinks south - which has big implications later in the week ... GFS looking more settled with HP building while ECM keeps the troughing.

Quite big differences ...

[tinybill]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

just looked deep into f1on here no let till at least may 12!!!

[Summer Sun]

GFS is better than ECM this morning with high pressure hanging on, its not a very warm run but in any sunshine and light winds it would feel pleasant in the ever stronger sunshine

http://www.jp2webdes...o.uk/ds/gfs.htm

The temperature outlook shows a rise in temperatures as we enter May

The Precipitation chart also shows a much drier outlook than of late, with the east coast seeing no rain at all for 8 days and most other areas see no more than 10mm

Changes appear to be coming with April showers giving way to somthing drier early May

[Thundery wintry showers]

I think the ECMWF operational is out on its own at the moment, although the ensemble mean doesn't fully support UKMO or GFS either, highlighting the uncertainty involved.

Sunshine and scattered showers for many tomorrow although an area of cloud and persistent rain is likely to be stubborn over south-east Scotland and north-east England. Saturday looks like being a dry sunny day in Scotland and northern England with cloudier wetter conditions approaching the south and then establishing over most of England and Wales on a rather cold wet Sunday, while staying dry and sunny in Scotland.

If the UKMO/GFS are to be believed then next week will be dry and sunny in western Scotland and NW England and Ireland, while southern areas will be more prone to active frontal systems bringing cloud and rain but also higher temperatures. The main question mark concerns eastern Scotland and NE England- in my experience while those winds off the North Sea often keep it bone dry they also tend to bring cloud in off the North Sea. For East Anglia and the SE you tend not to get much cloud unless the winds are north of east, but in E Scotland and NE England (with E and SE winds having a longer sea track than further south) even a south-easterly can generate a fair amount of stratus. The question will thus be how much cloud, and how far inland it gets.

[summer blizzard]

Whilst the medium term outlook certainly looks warmer, i am concerned that models persistently show low pressure near the south of the UK as minor changes would mean that rather than getting a few thundery showers, most of England would get a soaking from frontal rain-bands.

Not the best outlook in my opinion.

[SP1986]

I can't say I'm surprised really, however this outlook has always been on the cards.

It has always been the case that the north of England would be below average temperature wise for the foreseeable future, this will remain the case throughout a good portion of May I suspect, but southern England will see wetter weather and above average temperatures. Scotland more settled but average temperatures here; so really the losers in this pattern will be the north Midlands, Northwest England and North Wales who will see the cool weather continuing with the threat of persistent frontal rain.

Scotland doesn't look to be too bad, with more settled weather, but If I had a choice where I'd like to be in the next few weeks, it would most likely be southern England; rain or showery, potentially thundery but quite warm too.

The synoptics have been set like this for the last few days really, no major change.

ps Ive never known early May to look as cold as it does in FI, surely for those days it would be a record breaker for cold? Either that or the GFS has lost it? I can't imagine the former.

edit: Even the ECM shows some form of what the GFS shows too, maybe the signals actually do suggest there is the chance of at least a very cold start to May.

[Robbie Garrett]

That's incredible, very good synoptics at the end of the GFS for winter. What a complete joke. But I am not far from surprised. Coldest May in 100 years, whoever said it was damn right. -3*C in france? 1*C in England at min. OUCH!

[bluearmy]

you may be looking at gfs 06z op fi and thinking how ridiculous it is. it may be over doing it but this is where the fi ens are headed with mid atlantic ridging and scandi troughing. we will do well if we manage to lose the general weak euro trough.

[Zenarcher]

Looking at the GFS ensembles some interesting changes look to be made with high pressure taking charge for most.

At first pressure mainly over Northern parts.

By this time next week it shows high pressure moving more North probably giving us a slightly colder weather type.

But if we turn the clock closer to Sunday night we have a low pressure system being produced by the models and we have some disagreement here. The ECM wants to bring it up over the UK in the end it doesn't really show a blocked colder pattern like the GFS. Meanwhile the UKMO and the GFS have the low just to the South of Ireland the low then moves more South this seems to allow high pressure to our North get a better chance to become more dominate and create a blocked like pattern.

[Cheshire Freeze]

Pressure rising around Greenland again.....northerly plunge on the way?

Nothing like some -7 uppers to get out into the beer garden with enjoying the er snow risk....

Edited April 26, 2012 by CreweCold

[SP1986]

By next weekend parts of Northern England and the Midlands could have some staggering rainfall totals, which what looks to be, on the GFS chart, persistent rain all week with no respite on any day. It could be that the months rainfall totals are exceeded within a few days in early May. Something of interest to keep an eye on anyway. Thereafter all probability is that it will turn cold or very cold for the time of year as high pressure hangs onto Greenland (that is not going anywhere by the way).

Inside the realistic timeframe though there is nothing vastly different to say, still the same as the last few runs.

[Cheese Rice]

And it seems the warmer high pressure dominated weather ahead that was touted as a definite has disappeared on the GFS. Temperatures a good 10.c lower on this run with the potential for a significant northerly towards the end.

[Snowy Easterly]

completely off topic, but i was literally just going to go to my allotment and put my crops out as it looked to be warming up next week, good job i looked at the 12z as it looks like a northerly could be on the way in FI, but as it is spring it won't downgrade like it would do in winter

Sunday looks quite wet in England and Wales but will it be that wet in the east as most of the rain looks to be in the south and west to me

Edited April 26, 2012 by Snowy Easterly

[Cheese Rice]

By next weekend parts of Northern England and the Midlands could have some staggering rainfall totals, which what looks to be, on the GFS chart, persistent rain all week with no respite on any day. It could be that the months rainfall totals are exceeded within a few days in early May. Something of interest to keep an eye on anyway. Thereafter all probability is that it will turn cold or very cold for the time of year as high pressure hangs onto Greenland (that is not going anywhere by the way).

Inside the realistic timeframe though there is nothing vastly different to say, still the same as the last few runs.

Indeed.

Over 80mm here so far this month, some areas have exceeded 100m with 20-30mm expected from now till mid afternoon across Southern Northern England (Persistent heavy/torrential rain since 3pm here).

Interesting rainfall total projections by the GFS putting the south and east in the firing line for the next two weeks for the largest of rainfall totals, with the far north remaining fairly dry,

Edited April 26, 2012 by Cheese Rice

[Cheese Rice]

I wouldn't be at all surprised if in the next few months all this talk of drought has faded away judging by the phenomenally cool May currently projected.

Although nothing is a dead cert I wouldn't be surprised to see a continuation of this cold, wet pattern through the rest of may maybe even summer.

[SP1986]

completely off topic, but i was literally just going to go to my allotment and put my crops out as it looked to be warming up next week, good job i looked at the 12z as it looks like a northerly could be on the way in FI, but as it is spring it won't downgrade like it would do in winter

To be brutally honest, looking at the charts, I don't see how crops will suffice this year; summer crops anyway. They simply won't have the time by the time the weather gets back to the season average (if it does), to allow much growth, nevermind seeding/flowering/fruiting. I simply wouldn't bother. If I was a farmer and saw these charts, I would be getting very very nervous indeed. (that is assuming you are not talking about very hardy native fruit crops like Blackberries, apples etc)

[Milhouse]

Good grief, the cold ramping and doom mongering has surpassed anything i've ever read on this thread. Youd have thought that northerlies in May were a 1 in 100 year event judging by some of the comments.

[Cloud 10]

And it seems the warmer high pressure dominated weather ahead that was touted as a definite has disappeared on the GFS. Temperatures a good 10.c lower on this run with the potential for a significant northerly towards the end.

The 12z gefs ensemble mean at 192hrs very keen on teeing up a northerly.

Not sure this is the pattern change that most are hoping for!

[Snowy Easterly]

To be brutally honest, looking at the charts, I don't see how crops will suffice this year; summer crops anyway. They simply won't have the time by the time the weather gets back to the season average (if it does), to allow much growth, nevermind seeding/flowering/fruiting. I simply wouldn't bother. If I was a farmer and saw these charts, I would be getting very very nervous indeed. (that is assuming you are not talking about very hardy native fruit crops like Blackberries, apples etc)

To be brutally honest, looking at the charts, I don't see how crops will suffice this year; summer crops anyway. They simply won't have the time by the time the weather gets back to the season average (if it does), to allow much growth, nevermind seeding/flowering/fruiting. I simply wouldn't bother. If I was a farmer and saw these charts, I would be getting very very nervous indeed. (that is assuming you are not talking about very hardy native fruit crops like Blackberries, apples etc)

things like cucumbers, beans and lettuce can be seeded in early june so there is plenty of time for that, its just my impatience tbh because i want to get them outside, i just knew we would probably get some sort of northerly and today up pops a northerly on the charts, i bet it comes off as well even though it is in FI

Edited April 26, 2012 by Snowy Easterly

[Bristawl Si]

I knew that outside chance of warmer, settled weather had disappeared in the blink of an eye, as soon as i noticed that Gavin hadn't posted this evening!

[Bottesford]

I think the springs over and summers over posts are being very hasty indeed!

It was not a few weeks ago we had unending high pressure & above average temperatures. All models kept the theme going and going. But look - it changed - and it will change again.

Completely understand the frustration and impatience - as a gardener (first year really having a proper go at it) it is very depressing seeing everything not growing and being stuck with plants all over the house. But change will come and the plants will catch up.

Yesterday we saw hints of something warmer coming in next week - today a northerly. The models are being very fickle as there is a lot of uncertainty in the relatively near time frame. Don't panic just yet!

[Cheshire Freeze]

I knew that outside chance of warmer, settled weather had disappeared in the blink of an eye, as soon as i noticed that Gavin hadn't posted this evening!

Yeah, sometimes I don't even need to look at the model output when I see Gavin's name as the last posted in the mod thread lol

Good grief, the cold ramping and doom mongering has surpassed anything i've ever read on this thread. Youd have thought that northerlies in May were a 1 in 100 year event judging by some of the comments.

I'm just savouring the moment to be honest. I can do without days of sunshine burning into my skin and being over heated by sweaty and humid conditions. If I wanted any form of sustained heat, I'd go on holiday to a place that had it, rather than suffer the horrid, muggy (supposedly nice) heat of this island. The cooler (and wetter) the better as far as I'm concerned Plus if people can harp on about hot weather, high pressure and sunshine amounts I don't see why people can't harp on about cold, wet and low pressure dominated weather.

Edited April 26, 2012 by CreweCold

[Summer Sun]

ECM has reverted back to high pressure remaing tonight with milder air coming our way

Up to 168h

Monday wet for Many, Northern Scotland maybe the best place for drier weather

Tuesday, high pressure begins to take hold with the Northern half becoming drier and milder

Wednesday is the same

Thursday, high pressure remains in control across the north, whilst low pressure is to the south of the UK

Summary

Northern England and Scotland are likely to see the best of the drier and settled weather whilst southern parts will be most prone to rain

Edited April 26, 2012 by Gavin D

[Summer Sun]

High pressure remains on Friday and Saturday with hints of some cooler dry weather setting up during the weekend

Edited April 26, 2012 by Gavin D