Model Discussion - 10th March Onwards

[andy100]

Ice Bergs tomorrow by the looks of things

[summersnow]

Yes, models now showing a northerly airstream as looking likely, at least for a while!

I've been pointing out for a while now that the Met Office has consistently stuck to its guns with this outlook and given its track record this winter, I'm inclined to to agree! The Met office always comes in for stick when it gets things wrong but let's give credit where it's due - its been ahead of the game for most of this winter and even gave a winter probability forecast back in December, which has been spot on! Well done the Met Office....this winter!!

Also of note is that ECM has downgraded a little at 00z compared to most of its earlier runs, while GFS has moved everything a bit closer to the ECM solution - a fairly typical hybrid, as many of us suggested might happen and will be the most likely outcome IMO.

[The PIT]

ECM showing the main push of colder air going dopwn the north sea so unless everything shifts west by quite a bit it's another of those so close so far. High pressure still in charge so while the east coast may get some showers I suspect mostly dry with a risk of overnight frost depending on cloud cover amounts.

[TonyH]

Model based regionally specific weather guide for the coming week:

http://forum.netweather.tv/blog/309/entry-4376-weather-guide-monday-26th-march-to-sunday-april-1st-west-wales-and-central-midlands-specific/

[Paul White.]

These would of been nice in January

Bit further with 850 Maybe next winter :good:http://cdn.nwstatic.co.uk/gfsimages/gfs.20120325/12/138/h850t850eu.pnghttp://cdn.nwstatic.co.uk/ecmimages/20120325/00/ecm500.144.png

Edited March 25, 2012 by paulwhite22

[Summer Sun]

Although we may see some cooler weather into next week the drought problems look like seeing little help with rain fall over the next 10 days remaining low in the south

Edited March 25, 2012 by Gavin D

[Costa Del Fal]

As unsettled as the GFS 12z FI looks at first glance, very little rain reaches England and Wales as High pressure remains to our South but lower pressure to our North West after the brief colder shot next weekend. Both the colder shot and low pressure will get toned down im sure however a more mixed first half to April is on the cards but not much to ease the drought situation at all.

[Thundery wintry showers]

Looking over the current model outputs, most places look like staying dry, sunny and notably warm until Wednesday, with the cooler temperatures and low cloud receding from eastern parts of England as high pressure relocates further south, although at the same time it will become less warm across western areas. Not sure that high pressure is going to drift too far away after that to be honest.

The GFS 12Z run suggests a brief northerly outbreak on Friday/Saturday with some wintry showers possible from the Midlands northwards on Saturday (which would certainly be a shock to the system, from summer-like warmth and sunshine to snow showers) but we then get a ridge of high pressure back on top of us- the unsettled stuff doesn't make it over until after T+180.

Meanwhile, the ECMWF and UKMO runs don't really have much of a northerly outbreak, the main "shot" gets shunted out into the North Sea and we are left with high pressure and cooler temperatures. Due to the lack of a strong Atlantic influence the outputs imply a cloudier interlude spreading south on Thursday/Friday followed by more sunshine for the weekend. The ECMWF operational then has high pressure over the British Isles out to T+240 and the ensemble mean is hardly convincing with its Atlantic-driven weather (south-eastern areas still remain under high pressure).

Therefore in my view the outputs suggest staying generally dry and sunny with high pressure for the foreseeable future but temperatures falling close to average by day as we get into Friday/Saturday with overnight frost, then temperatures recovering above average again afterwards. I don't think the wintry showers for Saturday shown by GFS will materialise as the northerly will probably be shunted eastwards like UKMO/ECMWF show.

[Zenarcher]

Long Range

Looking ahead to next weekend most models show high pressure staying with us. JMA has high pressure to the West of the UK right up to the end of its run on the 2nd April. The ECM shows something similar but the high pressure is further East and more over the UK meanwhile the GFS keeps high pressure only over the far South of the UK leaving the rest to unsettled weather as low pressure systems pass over the far North of Scotland. Uncertain outlook at the moment but its two against one.

Monday to Wednesday Summary

England, Wales and Ireland will continue to see clear and sunny weather for the first few days of the week. Scotland will also join in but looks to get partly cloudy on Wednesday. The wind will be light across most parts but breezy at times in the West and North.

Thursday and Friday Summary

Over Scotland, Northern Ireland and Northern England a spell of mixed weather is likely. Turning mostly cloudy with mist and even some showers around as well but despite this anywhere can still expect short sunny periods. For Wales and the rest of Ireland and England it will stay clear and sunny but it might turn partly cloudy at times on Friday. The wind will be light in the South and Breezy in the North but across the far North of Scotland gales are likely.

[Costa Del Fal]

GFS 18z keeps the warm theme going right through until about 4th April now with no weekend colder shot at all! , just slightly cooler overall. It also remains settled in the South till then. Deep FI is quite unsettled but deep FI it looks to remain for now. I wonder what the ensembles will show. Certainly signs today, are beginning to move away from the brief Northerly but not necessarily so yet with plenty of time before then. However it looks like High Pressure will have a harder than expected job of retrogressing towards Greenland etc. Pressure looks like it could remain higher over the British Isles, continuing the pattern we are in now. Lots to think about with regards to the medium term.

Edited March 25, 2012 by Blizzards

[Polar Maritime]

The GFS this morning is showing a continuation of High Pressure over the uk, with warm sunny dry weather well into the run. A lovely week coming up, with no notable rainfall. Things will turn slightly cooler at the turn of the month with a cold Northerly showing at the end of the run.

[IDO]

As per most of the last three months, PM shots forecast in FI, have ended up mostly being tame non-events. Next weekend, as we near the reliable time frame, appears to be a case in point. HP hanging on meaning a cooler settled period for the south with the north having cooler temps. No sign of anything unseasonal. The Op run is also at the bottom 20% of cooler ensembles, so in reality, as the week progresses this may reflect in a milder outlook. GFS 0z also indicates a possible PM shot the following weekend (Easter), however again the Op run is right at the bottom of the colder runs. ECM (0z) is similar to GFS with a very glancing blow of cooler weather next weekend.

I suspect the really warm weather of late will end later this week but as that was around 7c over the average that is no surprise. It should still say average/mild for the foreseeable. The CET anomaly for Feb 2012 is at the moment +2.3 so no sign of wintry weather in Feb the last two years. The promise of changes globally this year due to El Nino should be interesting as the weather pattern this last eight months has been surprising. Obviously it has other importance, Olympics et al?

Edited March 26, 2012 by i'm dreaming of...

[Summer Sun]

Apart from a full on northerly on Saturday GFS shows high pressure winning out for all of this week and next week its not untill easter Saturday and Sunday that things are shown to change but with that been FI I wouldn't bet against it not happening, rain fall looks like staying very low for the areas in great need for the next 2 weeks

[Costa Del Fal]

Certainly a trend for High pressure continuing into next week now, just slightly cooler but still pleasantly warm in the sun. The North and perhaps East at times at risk of some unsettled weather at times but even though deep FI looks unsettled virtually no rain seems to make it to England and Wales.

[Summer Sun]

Saturday looks like turning cooler but high pressure remains with us

http://cdn.nwstatic....126/h500slp.png

Sunday is the same except slightly warmer

http://cdn.nwstatic....150/h500slp.png

Into the first full week of April it's more of the same as high pressure holds on with temperatures in the mid teens

http://cdn.nwstatic....174/h500slp.png

http://cdn.nwstatic....192/h500slp.png

By Wednesday we see low pressure moving in but it stays dry for many

http://cdn.nwstatic....216/h500slp.png

Thursday wet for some in the north dry further south

http://cdn.nwstatic....240/h500slp.png

Friday cold for all light rain in the south snow possible for high ground in the far north

http://cdn.nwstatic....264/h500slp.png

GFS end's dry and settled so overall there is not enough rain for the drought areas and it turns colder just in time for the easter weekend

http://cdn.nwstatic....airpressure.png

Edited March 26, 2012 by Gavin D

[Alex]

The 12z is a drier run, maybe a trend is developing, that the ridge really isn't keen to move that far. Even after next week, the 12z shows a ridge which extends from Greenland southeastwards across the Atlantic to the UK which is a very interesting situation.

[phil nw.]

What an amazing warm and sunny few days we are having,very agreeable for outdoor activities.

With few exceptions it looks like contniuing for a couple more days before cooling down from the north west from around Thursday reaching the far south by the weekend.

Still quite settled though for many with the high only moving slightly west into the near Atlantic.

http://www.wetterzen...cs/Rukm1441.gif

It seems that the main thrust of colder air goes further east into Scandinavia and eastern Europe with the UK temperatures returning to nearer normal.

Going by the 00z mean hts for days 8-10 it looks like high pressure will continue to dominate our weather further on into the start of April

http://www.meteo.psu...WF_0z/test8.gif

maybe not as warm with the flow more from the west or north west at times but still no appreciable break to the dry conditions on the horizon.

[Summer Sun]

ECM never sends high pressure too far away tonight with the south staying under pressure of no lower than 1020mb through-out even though it will be cooler than of late from the weekend we have certainly gone to a drier outlook tonight compared to previous runs

[johnholmes]

Looking at the latest 6 day statistics from NOAA it shows some, I think, highly unusual statistics?

On 5 out of the last 9 days UK Met scored below GFS, and even more surprising ECMWF did so on 6 days.

In all the time I've been looking at these statistics I can never recall seeing both perdorm so badly for so long compared to GFS.

It cannot have anything to do with the 500mb anomaly charts but they too are less reliable over the past 5-8 days than in a long time. I certainly would not use them to try and predict what the 500mb pattern will be in 8-15 days. It still looks like anticyclonic rather than cyclonic but even that I'm not totally sure about.

not sure why it will not enlarge?

having another closer look at the 500mb charts and comparing what was forecast for today-its about as close as any forecaster might hope with the upper pattern, and looking at how much it is predicted to change in the next 7-15 days then more unsettled would probably be the theme, more in the north than the south??

Time as ever will tell.

Edited March 26, 2012 by johnholmes

[bluearmy]

Looking at the latest 6 day statistics from NOAA it shows some, I think, highly unusual statistics?

On 5 out of the last 9 days UK Met scored below GFS, and even more surprising ECMWF did so on 6 days.

In all the time I've been looking at these statistics I can never recall seeing both perdorm so badly for so long compared to GFS.

It cannot have anything to do with the 500mb anomaly charts but they too are less reliable over the past 5-8 days than in a long time. I certainly would not use them to try and predict what the 500mb pattern will be in 8-15 days. It still looks like anticyclonic rather than cyclonic but even that I'm not totally sure about.

not sure why it will not enlarge?

having another closer look at the 500mb charts and comparing what was forecast for today-its about as close as any forecaster might hope with the upper pattern, and looking at how much it is predicted to change in the next 7-15 days then more unsettled would probably be the theme, more in the north than the south??

Time as ever will tell.

current cpc output comes with lowest confidence JH. NOAA appreciate that the nwp is not performing too well at the moment.

[summer blizzard]

Looking at the latest 6 day statistics from NOAA it shows some, I think, highly unusual statistics?

On 5 out of the last 9 days UK Met scored below GFS, and even more surprising ECMWF did so on 6 days.

In all the time I've been looking at these statistics I can never recall seeing both perdorm so badly for so long compared to GFS.

It cannot have anything to do with the 500mb anomaly charts but they too are less reliable over the past 5-8 days than in a long time. I certainly would not use them to try and predict what the 500mb pattern will be in 8-15 days. It still looks like anticyclonic rather than cyclonic but even that I'm not totally sure about.

not sure why it will not enlarge?

having another closer look at the 500mb charts and comparing what was forecast for today-its about as close as any forecaster might hope with the upper pattern, and looking at how much it is predicted to change in the next 7-15 days then more unsettled would probably be the theme, more in the north than the south??

Time as ever will tell.

Correct me if i am wrong but the green line (GEM) also looks to have performed very well, confirming to me that it has been in the ascendancy for the past few years.

[The PIT]

Very brief spell of normal by day temps coming over the weekend before returning to above normal. High pressure never far away although hanging around to the west instead of the east so not as warm as has been. Little in the way of rain by the looks of things as well.

[johnholmes]

current cpc output comes with lowest confidence JH. NOAA appreciate that the nwp is not performing too well at the moment.

yes I did have a quick look at their discussion and noted they score things at 1/10 for 6-10 and 8-14 day outlooks-its for their own neck of the woods but it does give a flavour of the overall ideas for the northern hemisphere around our patch as well.

I wonder what it is that is giving so much model trouble?

[Alex]

yes I did have a quick look at their discussion and noted they score things at 1/10 for 6-10 and 8-14 day outlooks-its for their own neck of the woods but it does give a flavour of the overall ideas for the northern hemisphere around our patch as well.

I wonder what it is that is giving so much model trouble?

Could it be the rapidly decreasing levels of La Nina coupled with low angular momentum?

Edited March 27, 2012 by Alex

[johnholmes]

I can't quite see how either can be having so much effect on the models at fairly short time scales.