Model Output Discussion

[SP1986]

http://www.wetterzentrale.de/pics/brack4.gif - Wintry showers moving southwards.

Strange comments on TWO saying the cold plunge has gone to our east, looks dead set for the UK to me with the 528 dam line moving southwards dwon the spine of the mainland and will probably sit through the midlands giving some very cold nights with light winds.

Yes there is uncertainty but it does seem the cold plunge does have the UK's name on it. Even if the plunge went to the East it would still be cold. We are in a scenario where no matter what pattern evolves we most likely will be cold, unless the warmer airmass moves in from the southwest. At the moment the previously predicted southerly is on very very shaky foundations.

I don't think it'll be very cold though, widespread temperatures of -3 to -4C are probably very rare towards the end of April.

The NAO and AO continually progresses on the negative side too, if this continues we can probably kiss goodbye to the prospects of a warm summer, and although this may seem premature, this NAO/AO has been continually negative for months on end, so it doesn't really look like letting up either, so perhaps forecasting a very cool summer isn't so groundless?

[reef]

Yes there is uncertainty but it does seem the cold plunge does have the UK's name on it. Even if the plunge went to the East it would still be cold. We are in a scenario where no matter what pattern evolves we most likely will be cold, unless the warmer airmass moves in from the southwest. At the moment the previously predicted southerly is on very very shaky foundations.

I don't think it'll be very cold though, widespread temperatures of -3 to -4C are probably very rare towards the end of April.

The NAO and AO continually progresses on the negative side too, if this continues we can probably kiss goodbye to the prospects of a warm summer, and although this may seem premature, this NAO/AO has been continually negative for months on end, so it doesn't really look like letting up either, so perhaps forecasting a very cool summer isn't so groundless?

Its looking very likely we'll see a potent northerly now. How far south it pushes is still up in the air, but needless to say, with the -10C 850hPa isotherm moving almost as far south as the Scottish borders then its pretty much as cold as you can get this late in the season. Temperatures of -4C or -5C are rare in late April but very much a possibility in this setup with temperatures possibly much lower in the Highlands.

You cant really judge what summer will be like based on patterns right now. Indeed, last October and November were rather mild, yet the pattern flipped in December and we had the coldest winter for 31 years! If we get to June and the same pattern is showing, then perhaps the alarm bells will start ringing, but bear in mind a -ve NAO/AO isnt necessarily bad for our summer. A strong (and tracking over the UK) jet would be the main thing to watch out for.

[❄️❄️❄️❄️❄️❄️❄️❄️❄️]

Bring it on!

Edited April 17, 2010 by RAIN RAIN RAIN

[dogs32]

Hi guy's

does anyone have a idea how long this northerly will last?

when will the S/W winds come back?

many of us have to be on flights in over a week

Edited April 17, 2010 by dogs32

[phil nw.]

Hi guy's

does anyone have a idea how long this northerly will last?

when will the S/W winds come back?

many of us have to be on flights in over a week

Signs that the cold pattern will break down just beyond the reliable time frame based on the 00z runs.

http://www.wetterzentrale.de/pics/Rukm1441.gif

http://www.wetterzentrale.de/pics/Recm1681.gif

http://www.wetterzentrale.de/pics/Rtavn1681.png

Looking quite pleasant in the South this weekend and then somewhat cooler next week with night frosts around.

[dogs32]

Signs that the cold pattern will break down just beyond the reliable time frame based on the 00z runs.

http://www.wetterzentrale.de/pics/Rukm1441.gif

http://www.wetterzentrale.de/pics/Recm1681.gif

http://www.wetterzentrale.de/pics/Rtavn1681.png

Looking quite pleasant in the South this weekend and then somewhat cooler next week with night frosts around.

cheers,

some hope then,have to keep an eye on this..thx

need our South Westerly to kick back in..

Edited April 17, 2010 by dogs32

[Higher Ground]

Temp down to -2C in Birmingham last night, -1C in Pershore.

So with a colder setup, widespread -3C/-4C would clearly be easily attainable.

Edited April 17, 2010 by Higher Ground

[ANYWEATHER]

Temp down to -2C in Birmingham last night, -1C in Pershore.

So with a colder setup, widespread -3C/-4C would clearly be easily attainable.

Yep,quite agree! Down to minus,1c at my weather station between 5.30 and 7 am this morning! Anyway, back to the models, and it looks as though a lot of quiet ,settled weather for the forseeable future especially if the Ecm verifies, gfs somewhat more unsettled on its latest run. Frost almost anywhere next week so if youre growing tender plants make sure you cover them up overnight!! If I was going to stick my neck out I would say especially for the southern half of the Uk will hold onto a lot of dry settled weather even in to May...watch this space!!

[SP1986]

re: You cannot guarantee the skies will be clear in a northerly, even high pressure to that extent, the only way they would reach -3 or -4C is if there was clear skies and no wind from 1800-0600 - I find that unlikely in most parts. At this time of year even with upper air temperature of -5C with any breeze blowing it will struggle to get below -2C. In fact this is true of winter as well in most cases.

The point being yes you could get this low temperature however the conditions in the Midlands and Southwest England were perfect last night, clear skies, low humidity,no wind - something that can't always be guaranteed.

I'm growing tender plants actually, I wont need to cover them up though because generally even in those scenarios the coast wont get a frost. In fact with predicted winds from the Northwest I can rest happy, in terms of my plants anyway

[Stamford Bobby]

Morning all,

I've come here for some expert advice!!! Can anyone tell me if the models are showing whether the wind direction over the next few days will blow this volcanic ash cloud away? My wife is stuck in Romania and is on a flight for thursday, but tv forecasters seem to be avoiding making any predictions.

From what I've read on here it seems we are in a northerly for a few more days.

Apologies if this is off-topic, but it kind of is related to the models!

Thanks

[ANYWEATHER]

Morning all,

I've come here for some expert advice!!! Can anyone tell me if the models are showing whether the wind direction over the next few days will blow this volcanic ash cloud away? My wife is stuck in Romania and is on a flight for thursday, but tv forecasters seem to be avoiding making any predictions.

From what I've read on here it seems we are in a northerly for a few more days.

Apologies if this is off-topic, but it kind of is related to the models!

Thanks

Im not saying im an "expert" on this but Ive posted some charts from the latest gfs Jetstream and unfortunately shows the Uk in line for Volcanic ash all next week thats if it keeps erupting! I would imagine the jetstream being a high level wind will be the one to watch over the coming days,the jet does look like changing direction in about a weeks time ,"if" the model is correct...I hope that helps!!

[Stamford Bobby]

Im not saying im an "expert" on this but Ive posted some charts from the latest gfs Jetstream and unfortunately shows the Uk in line for Volcanic ash all next week thats if it keeps erupting! I would imagine the jetstream being a high level wind will be the one to watch over the coming days,the jet does look like changing direction in about a weeks time ,"if" the model is correct...I hope that helps!!

Thanks for your opinion, seems to be the general concensus so I'd say you're probably right.

[MR EXTREMES]

yes i think the polar jet will move north at some point this week along with the tropical jet,

there hints the weather becoming warmer mid week onwards.

so this clearly would mean polar jet and tropical jet pushing north until then things set to coninue as they are.

Edited April 17, 2010 by badboy657

[Frosty.]

Great model output this morning for cold lovers for next week with several days of N'ly to NW'ly winds of arctic origin which will bring wintry showers to the northeast and widespread frosts but with plenty of sunshine and clean clear air apart from volcanic dust fallout of course The models have prolonged the cold snap today but it should become milder again in around a week and today & tomorrow still look fine and pleasantly warm for most of england and wales but becoming wetter across scotland and colder air digging south tonight and tomorrow in the far north with wintry showers and snow on hills.

[Stormyking]

yes i think the polar jet will move north at some point this week along with the tropical jet,

there hints the weather becoming warmer mid week onwards.

so this clearly would mean polar jet and tropical jet pushing north until then things set to coninue as they are.

That would be nice i hope we get more warmer weather soon. The GFS does show nice warmer weather end of next week onwards probably is still far out but i think it will warm up alot more soon.

[Derp Patrol]

I must say that this week is looking very good for the southern half of the UK.. there will definately be a cooling wind, but apart from that I see plenty of sunshine and pretty average temperatures by day with high pressure close by.

I'm definately not writing summer off, like Reef said, things can change suddenly like this past winter which most people including myself predicted would be mild. Also, weren't we in a similar situation at this point in April 2006?

If this pattern did persist into Summer, then I would sugest the SE/NW divide with warm sunny weather in the south and unsettled cooler weather the further north.

Edited April 17, 2010 by robthefool

[Frosty.]

If this pattern did persist into Summer, then I would sugest the SE/NW divide with warm sunny weather in the south and unsettled cooler weather the further north.

Hmmmm is that not the normal default summer pattern, the weather is always warmest in the southeast and coolest in the northwest which has a more atlantic influence, as for the models, the ecm 00z looks promising by the end of the run with high pressure in a favourable position to pull warm winds off the near continent.

Edited April 17, 2010 by Frosty039

[Ben_Cambs]

RE April 2006, I was trying to find some sort of past teleconnection archive, whether the NAO and AO was positive or negative, the positioning of the sub-tropical and polar frontal jets etc. What I did find from the NOAA website from the past NAO monthly mean records was that the NAO was slightly -ve in April 2006( though this was an average).

http://www.cpc.noaa.gov/products/precip/CWlink/pna/month_nao_index.shtml

Looking at the Wetterzentrale archives though for April 2006, it was a much more unsettled month than this month, with at times a NW/SE split, HP tried for a long while to build in from the south west but failed to do so, due to the Atlantic. It was only at the end of the month when HP finally moved in giving conditions similar to what we have been experiencing lately. There were no 20C+ days recorded in Cambridge in April 2006.

We have still got a long time until the summer, and we have up to September really for hot spells of weather to occur, and they can even occur in early October too.

We will see what happens to the NAO,AO etc as the summer months come closer.

[summer blizzard]

I must say that this week is looking very good for the southern half of the UK.. there will definately be a cooling wind, but apart from that I see plenty of sunshine and pretty average temperatures by day with high pressure close by.

I'm definately not writing summer off, like Reef said, things can change suddenly like this past winter which most people including myself predicted would be mild. Also, weren't we in a similar situation at this point in April 2006?

If this pattern did persist into Summer, then I would sugest the SE/NW divide with warm sunny weather in the south and unsettled cooler weather the further north.

Indeed, away from Scotland, the weather for the next week looks fantastic, with signs of high pressure moving further east giving the chance of a warm plume.

In regards to April 2006, it was April 2007 which was the hot one, however high pressure refuses to budge at the moment and as such i am very tempted to call for a hot May, however i think that mid to late May will tell us what the first half of summers pattern will be, because either the Jet Stream will move north properly, or high pressure will retrogress to Greenland. Ironically, i actually want a wet spell in late May/early June to indicate the Jet tream moving north (European Monsoon).

Also, in regards to the models, there are some fantastic charts showing up after next weekend, with both the GFS and ECWMF supporting a big switch to warmth, no draw from Spain so i doubt we will challenge the monthly record, however low to mid twenties is definitely on.

GFS: http://www.wetterzentrale.de/pics/Rtavn2401.png

ECWMF: http://www.wetterzentrale.de/pics/Recm2401.gif

GEM also agrees, so thats all models upto 240 hours out.

[k19]

Is it just me or is the GFS suggesting a weatherfront moving in in the next 48 hours (from the north)- presumably that will carry this volcanic ash further towards us.?But I have to say i'm confused by the GFS, it shows cold 850's above us, yet we are seeing hot days, does the high pressure ridge to our south cancel that out?

Sorry if i'm massively behind, i have been searching for a spotify invite for ages...

[summer blizzard]

While there is a cold front moving south overnight and tommorow, high pressure builds pretty much straight away behind it, and at this time of year that means high maxima.

[ribster]

Indeed, away from Scotland, the weather for the next week looks fantastic, with signs of high pressure moving further east giving the chance of a warm plume.

Looking 'very good' and 'fantastic', I must have missed something, temps of 9 - 12 by day (certainly for this location), and ground frosts at night? Excuse me if I don't get too excited. After the last few days, next week will feel chilly.

Edited April 17, 2010 by ribster

[Derp Patrol]

Looking 'very good' and 'fantastic', I must have missed something, temps of 9 - 12 by day (certainly for this location), and ground frosts at night? Excuse me if I don't get too excited. After the last few days, next week will feel chilly.

It won't be warm, but in the south there will be plenty of sunshine and it won't be as low as 9C, more like 11-14C from the midlands southwards and in hot spots 12-15C

[mushymanrob]

im not so sure itll be cold either, not by day when the sun will get things warmed up nicely. chilly nights but thats pretty much normal under such circumstances. its looking like the atlantic might be kicking in next weekend, at least it should clear the volcanic ash from our atmosphere. in all the gfs and ecm offer a pretty average outlook.... good!

[Frosty.]

A very cold week ahead for NE Scotland and N. Isles with an arctic airflow for much of the time and with occasional troughs which could bring some heavy snow in places, mostly on hills and widespread frosts but some sunshine and wintry showers at times. Away from the far northeast it doesn't look too bad, much cooler than recently of course but with lots of sunshine it should feel pleasant but overnight slight frosts are likely for a while and a few showers scattered around. The models are still suggesting a change in wind direction by next fri/sat with milder/warmer air covering most of the uk by next weekend but certainly the gfs, ecm and ukmo show a cold snap for the northern half of northern britain during the next five days.