Model Output Discussion - 1st February Onwards 12z--->

[IDO]

Looking at the next 10 days for widespread snow this morning not one of the fronts (4) or LP systems that cross the UK in that period is of snow, based on the GFS 0z. Plenty of hill snow for the usual suspects and of course Scotland has its own micro-climate so they should be more than likely have a better chance. Any wintry weather is from showers and to sea level these are the west and NW, and maybe once or twice these showers will move inland. However for the S/SE/East, low probability at the moment (10-15%). It is the usual culprit, as the LP systems move in they modify the uppers and it is not till they pass through that the colder flow re-establishes.

 

Alternating mild and cool days so any snow will not last if it settles at all. Some of the milder periods are quite apparent:

 

 

 

Over all the colder flows last around twice as long as the milder interludes.

 

The models started off with HP in charge from the end of the week and then went full scale zonal and now they are moderating it to PM and TM bursts with some drier ridging from the south (GEM and GFS). 

 

The main signal from the next 10 days are the storm potential, 2-3 possible. Lots of variance as one would expect, but worth watching.

 

As expected later in FI we are now seeing the PV looking less of a driver and the ensembles reflect this. At the moment little in the way of a clear signal emerging as to the next phase of weather but pressure building in our region looking the main cluster rather than it falling. 

 

In the near term the low moving into the south on D3 has only a 15% chance of some snow on the ensembles and the WRF hi-res has it as a rain only event:

 

[Frosty.]

There could be a few snowy surprises as early as Friday according to the Gfs 00z op with knife edge rain to wet snow, could be a tricky day for the met office regarding possible warnings.

[Polar Maritime]

The GFS is showing plenty of prospect for Snow from North to South within the next 10 days and beyond, With both the GFS & ECMWF continuing to show cool/cold Wintry/Stormy Pm shots through-out the runs into early March.

 

Edited February 18, 2015 by Polar Maritime

[BlueHedgehog074]

Once today's ridge of High Pressure over South-Eastern areas (which should provide a generally bright and dry weather for Eastern and South-Eastern areas with rain and drizzle over North-Western spots) gets knocked further East, the models are in great agreement to see a mobile, Westerly, setup take over. While the models still don't show any true High Latitude Blocking with very Low 500mb heights continuing to dominate to our North and North-West, they do show some fairly potent Polar Maritime shots behind spells of general rain, as Atlantic Lows track further East through Northern UK and dumps colder air down from the North-West through the UK. Nothing really out of the ordinary for February, but would probably say that the models generally keep the UK on the cooler side of things for next week with the Azores High Pressure held up to our South-West. Those in Northern areas would benefit the most from the cool and cold conditions (if it's the type of weather you're after), and the areas most likely to see some sleet and snow showers at times, especially over the hills. But considering the models do show areas of -5/-6/-7*C 850 hPa temperatures being quite widespread at times next week, and with the 500mb thicknesses looking quite low at times, even those further South could see some wintry weather at times, though sleet and snow would probably be most likely over the hills. Though if the showers or longer spells of precipitation can be heavy enough, then some sleetiness or wet snow can't be ruled out for lower level areas to the South.

With the models showing the Atlantic Lows next week being intense, then it's likely to be very windy at times, especially to the North-West, with some very strong gusts possible. While the weather for the British Isles looks to be mostly unsettled, some brief ridges over Southern areas could settle the weather down briefly, (but the best of any drier spells would likely be in the South). It might not be the ultimate dream most of the cold and snow fans are looking for (for now), but perhaps something their to keep some of those after cool and wintry conditions excited. Especially if you're in the North-West.

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS.

THE CURRENT GENERAL SITUATION A ridge of High pressure across Southern Britain will decline and move away South as a SW flow ahead of a trough of Low pressure movng SE across the UK tonight and tomorrow.

http://www.wetterzentrale.de/pics/Rtavn001.gif

MODELS-2 WEEK HEADLINE Changeable and very windy weather seems likely  with strong winds and heavy rain or wintry showers for all areas at times. Near average temperatures but rather cold at times in the North and feeling cold everywhere.

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream Ensemble Forecast shows a stronger flow later this week directed South across the UK and then setting up a position West to East across a more Southerly latitude than of late close to Southern Britain with a continuing trough/ridge pattern North and South over the UK for the remainder of the period.

http://www.netweather.tv/index.cgi?action=jetstream

GFS OPERATIONAL The GFS operational today shows a broad and very strong Westerly flow developing across the UK towards the weekend and lasting through the remainder of the run. With winds predominantly from the West and very strong with gales at times it will never feel overly mild but never be actually overly cold with spells of windy weather with periods of rain alternating with brief colder periods in NW winds and showers, wintry on hills these especially across the North. The North and West will always be favoured for the strongest winds and heaviest rainfall though all areas are shown to capture some.

http://www.wetterzentrale.de/pics/Rtavn1441.gif

http://www.wetterzentrale.de/pics/Rtavn3841.gif
 
THE GFS CONTROL The GFS control run shows similar conditions to the operational in Week 1 but rises pressure substantially over the British Isles in Week 2 with High pressure becoming dominent again with light winds and bright days replacing wind and rain but with the eventual return to some frost at night in temperatures otherwise close to average.

THE GFS CLUSTERS The GFS Clusters today continue to show an Atlantic Westerly or NW'ly with High pressure to the South and SW with West or NW winds delivering rain at times to all though there are some member groups of around 20% who show a similar evolution to the Control run in bringing back High pressure closer to Southern Britain later.

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

UKMO UKMO this morning shows a deepening Low moving East from Iceland to Scandinavia early next week with a band of rain and gales quickly replaced by rather chilly and showery WNW winds with sleet and snow showers over hills especially those in the North, all this following a spell of rain on Friday and a chilly and showery weekend under a NW flow.

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

THE FAX CHARTS The Fax Charts this morning show the High just to the South of the Uk declining ahead of a cold front moving SE tonight and tomorrow. This is then followed by a couple of wave depression crossing East over Southern Britain on Friday with an interesting cocktail of rain, with sleet or snow in places on the northern edge before a chilly NW flow is shown over the weekend and a following warm front towards Western Britain on Sunday.

http://www.weathercharts.org/ukmomslp.htm#t120.

GEM GEM also shows Westerly winds developing strongly over the UK carrying fast moving bands of rain followed by showers, wintry on hills for many. Some drier and brighter periods under transient ridges are also shown later in the run but they look relatively short-lived.

http://www.wetterzentrale.de/pics/Rgem2401.gif

NAVGEM NAVGEM shows Low pressure in total control from the end of this week with a lot of rather cold and windy weather under a West or NW flow. There will be days of sunshine and wintry showers mixed with short spells of more continuous rain as well when gales are possible.

http://www.wetterzentrale.de/pics/Rnvg1681.gif.

ECM ECM too shows a lot of chilly air crossing the Atlantic Ocean over the UK from the Greenland area under Low pressure stretching from Iceland and down over NW Europe. Fast moving fronts in the flow will each bring their own version of rain with snow on hills and followed by cold blustery weather with wintry showers especially in the North and West, this theme lasting out to day 10 and probably beyond.

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

ECM 10 DAY MEAN The 10 Day Mean Chart this morning continues to paint a synoptic pattern that has been repeated several times this Winter in our unsettled spells in that Low pressure stretches from Iceland to a deep trough over Europe bathing the UK in chilly West or NW winds and rain or wintry showers at times.

http://www.wetterzentrale.de/pics/Reem2401.gif

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models continue to all agree on a shift towards a deeper unsettled period with strong winds and rain or showers (wintry on hills) in a pattern of Low to the North and High well to the South and SW of the UK.

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKM & ECM The current verification statistics for the past 31 days shows ECM leading the way at 3 days with 97.4 pts followed by UKM at 97.0 pts and GFS at 96.1. At 5 days ECM just about leads the field at 89.4 pts over UKMO at 88.2 pts and GFS at 86.2. At 8 days ECM remains the leader with 61.6 pts over GFS's 59.3 pts. Then at Day 10 ECM retains superiority at 44.0 pts over GFS at 40.9.

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.prig
 

MY THOUGHTS We are now looking down the barrel of a period of much more volatile weather when everything bar the kitchen sink could be thrown at us over the coming two weeks. The next 24 hours will be the last of the fairly quiet weather with a band of rain tomorrow introducing a much more unsettled period for all and not just the North. Indeed on Friday there could be an interesting spell when cold lovers could see some of the white stuff over the higher ground from the Midlands North for a time as a wave depressions crosses East over the South into the cold air introduced by tomorrows trough of Low pressure. Then a chilly NW'ly on Saturday with some wintry showers is the precursor to a very windy spell with gales, heavy rain followed by squally thundery showers is likely next week with sleet and snow over northern modest elevations at times. The details beyond the middle of next week then become harder and less important to verify in a day to day way but the thrust of the outut suggests many more days of often windy and wet weather intermixed with days of squally, heavy showers which contain a not unusual late Winter/early Spring mix of rain, hail, sleet, snow and thunder. In among all this there is some drier and brighther conditions to be had but this will always be offset by an almost incessant strong breeze. In the far reaches of the output that stretches that far there is some suggestion that things may quieten down towards the end of the first week of March but details on how and when this transpires is hard to quote at the moment and in the meantime we should all batten down the hatches for some interesting and sometimes wild weather for weather lovers if not for snow lovers though having said that it is imperative to say that Northern hills and mountains should do very well for this stuff over the up and coming period while elsewhere fleeting interest is all any snowfall is likely to offer.  

Issued at 08:30 Wednesday February 18th 2015

[johnholmes]

The anomaly charts are quite interesting over the past 2-3 days. ECMWF-GFS have both decided to veer the upper flow over the UK which pulls in quite cold upper air (500mb) over much of the UK, not quite so much the further south and west one lives. NOAA 6-10 has only just started to follow this idea and is quite a bit less solid on this idea.

However I think it is clear now that a 'colder' spell of weather is going to develop 3 or 4 days from now and perhaps last for 5 to perhaps 7 days on CURRENT guidance from these outputs.

Judge for yourselves with the links below

 

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

 

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

Edited February 18, 2015 by johnholmes

[winterof79]

Snow is a distinct possibility on the North/western flank of the low as it tracks N/E 

The colder air then tucking in behind it Saturday.

 

 

Edited February 18, 2015 by winterof79

[Frosty.]

Ecm 00z ensemble mean is looking better for coldies with frequent Pm incursions of sub -5 T850 hPa and snow showers piling in from the northwest behind active frontal systems. The jet alignment becomes nw/se with vigorous depressions swinging SE, these polar maritime incursions look like being very potent with snow, ice and frosts during the cold blasts.

Edited February 18, 2015 by Frosty.

[IDO]

Snow is a distinct possibility on the North/western flank of the low as it tracks N/E 

The colder air then tucking in behind it Saturday.

 

 

 

 

Don't really see it for sea level, not even close, though hills maybe? 06z:

 

 

 

 

 

[winterof79]

Don't really see it for sea level, not even close, though hills maybe? 06z:

 

54-779UK.GIF  57-779UK.GIF

 

54-526UK.GIF 57-526UK.GIF

 

54-7UK.GIF

GFS has the precipitation further south then ECM though.The track is not sorted yet and elevation will be a factor i agree.

 

Edited February 18, 2015 by winterof79

[winterof79]

These precipitation charts are hilarious, most of the precitstion that will fall will be wintry mix, more likely to be rain and abit of sleet. No snow cover away from the highest ground in Scotland, really don't see the excitement, with the longer days and the strength of the sun getting stronger day by day this will in turn be another dull, wet and windy spell that we can stick in the bin with the rest of this winter cold snaps. Countdown to spring has well and truly begun for a lot of us.

You spilt what was left in your cup on the way in   Plenty of people live on higher ground.Only need 150mt plus to provide snow.

Edited February 18, 2015 by winterof79

[winterof79]

As BA alluded to earlier,a colder shot lining up at months end

 

With disturbances tracking across the south of the country

 

 

Edited February 18, 2015 by winterof79

[Nick F]

My latest Synoptic Analysis - an increasingly unsettled and sometimes disturbed weather pattern for the last 10 days of February:

 

http://www.netweather.tv/index.cgi?action=news;storyid=6464;sess=

[winterof79]

My latest Synoptic Analysis - an increasingly unsettled and sometimes disturbed weather pattern for the last 10 days of February:

 

http://www.netweather.tv/index.cgi?action=news;storyid=6464;sess=

Thanks Nick.Still some patchy snow on the higher hills around here from the last batch of Polar North Westerlies.The theme of this winter.

Edited February 18, 2015 by winterof79

[Frosty.]

Wave after wave of polar maritime air sweeping southeast behind active frontal systems during the outlook period according to the Gfs 06z and a wintry start to the meteorological spring. The Pm blasts vary in potency and length, some lasting two or more days at a time, especially across Scotland and the snow will be piling up on northern hills and mountains. This run also shows leading edge snow as Atlantic fronts bump into the cold air.

[Ali1977]

GEFS although not showing many really good charts for coldies are still looking more interesting in FI, large high over scandy looking to head a little further west on some, weaker PV around greenland on others. P15 looks about the best although not many following it's northern blocking FI. Just a shame FI is now early March, its around the time of year when even coldies start to look forward to some early Warmth, unless you are on higher ground further North where March can still produce some good snow.  Discounting March 2013 as a once in a lifetime event that is.

[steveinsussex]

At least there will be some interesting model watching periods coming up.

[Frosty.]

The last very mild day in Scotland for some time, the Moray Firth is likely to reach a very springlike 15c 59f this afternoon with sunny spells and south westerly winds but relatively much colder, windier and unsettled weather is on the way.

[Polar Maritime]

A few posts have been moved/removed, If you think a post should not belong in here please hit the report button instead of replying to it.

Many Thanks, PM.

Edited February 18, 2015 by Polar Maritime

[Mucka]

The upcoming spell has been very well signposted so not too much to add.

The GFS has slowly come on board with the Euros re deeper more influential troughs and it handled the mid term poorly for some time having the Azores ridge far too influential.

This cool/cold zonal phase looks likely to last into early March whereupon the signs are high pressure will look to become more prominent (and good to see MetO backing this idea in 30 day forecasts) though what shape any blocking takes and whether it can get into the higher latitudes is hard to know - best guess for now would be more mid latitude blocking.

 

Until that shows its hand in the output though we will be more inclined to pick out likely transient snow events as this zonal spell sets up.

Edited February 18, 2015 by Mucka

[IDO]

A couple of very nice days in the south with a sunny 10.5c reached already today in London (15.3c in Scotland today as well). Shame it all changes tomorrow. Just to show how poor ECM is with it's temp forecasts. It's 0z run suggested a max of 8c for London:

 

 

Pretty poor at that range. However it consistently underestimates temps so not a shock for me. Forecast highs from UKMO for the next 4 days for London are 7, 8, 7 & 9c so above average and by the weekend I will expect the CET to be back above average for Feb.

 

Despite the coldish westerly flow, I am not seeing anything wintry at sea level and as IF tweeted for the SW:

 

  fergieweather
W COUNTRY Rain Thurs & Fri...unsettled & often windy weather prevails frm Sun into end of Feb; with this pattern continuing into early March
18/02/2015 15:01

 

Very zonal and reminiscent of Winter 13/14 for the south. Looking at the CFS it does look like any promise for a late HLB pattern is slipping away as it has throughout this winter. The latest March anomaly:

 

 

 

If we can push that pattern further north maybe a pleasant start to Spring. 

[KyleHenry]

My latest Synoptic Analysis - an increasingly unsettled and sometimes disturbed weather pattern for the last 10 days of February:

 

http://www.netweather.tv/index.cgi?action=news;storyid=6464;sess=

Completely agree, High pressure systems N Pacific and Sibera putting the squeeze and elongating the cold air away from US into North Atlantic. Unsettled is the theme and as always the UK is getting the okay dokay treatment towards the first week of March.

What happens after this phase has still some interest for model watching

[stodge]

Afternoon all

 

A rare chance for me to peruse the evening output.

 

GFS indicating some very disturbed conditions to end the month

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015021812/gfs-0-192.png?12

 

The third of a group of increasingly vigorous depression so plenty of wind and rain and probably snow for the Scottish elevations.

 

GEM also looking profoundly disturbed with some strong depressions near Scotland and plenty of PM airmasses which wouldn't be warm and again looking good for blizzard conditions to altitude in Scotland and perhaps elsewhere.

 

UKMO has this strong winter storm for the end of the weekend and early next week:

 

http://www.meteociel.fr/ukmo/runs/2015021812/UW120-21.GIF?18-17

 

Certainly a change from the recent benign conditions and a reminder to even the most snow-starved that early spring is as much if not more likely to deliver the goods than parts of winter.

 

Out into the furthest recesses of FI and not much changing:

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015021812/gfsnh-0-300.png?12

 

The resilience of the PV in the absence of any significant SSW has been a strong feature of the second half of winter. Some will point to solar activity as a key player - others to extended LP to the NE of Scandinavia which may both play a part but none of the key indicators (MJO, AO, NAO) have given us any kind of help this winter - AO has dropped negative only briefly on three occasions,

 

I also thought along with someone on top of a Surrey hill that we might see blocking establish in early March but that appears to be dead in the proverbial now as the jet has fired up big time. None of this excludes the blocking establishing later on and while there's much talk of spring I'm to be convinced we won't have a cold surprise or two later in March - snowy Easter anyone ?

[fergieweather]

 

I also thought along with someone on top of a Surrey hill that we might see blocking establish in early March but that appears to be dead in the proverbial now as the jet has fired up big time. None of this excludes the blocking establishing later on and while there's much talk of spring I'm to be convinced we won't have a cold surprise or two later in March - snowy Easter anyone ?

 

The anomaly signal for rising MSLP by mid-March is now looking stronger as of this morning's GloSea run (and thus reflected in latest UKMO public forecast wording). GS5 aligns itself steadily closer with the last EC Monthly prognosis, albeit the latter sees (sizeable area of) HP becoming more dominant to SW/W, whereas the UKMO model favours anticyclonic conditions establishing more centrally across the UK. So, moderate confidence now in this sort of benign outcome by mid-month, but very little confidence on associated temperature regime (given divergent signals for the block positioning). Either way, some increasing optimism for a more settled, drier story emerging by mid-March but insufficient confidence, for now, to get too excited by it just yet.

Edited February 18, 2015 by fergieweather

[knocker]

The anomaly signal for rising MSLP by mid-March is now looking stronger as of this morning's GloSea run (and thus reflected in latest UKMO public forecast wording). GS5 aligns itself steadily closer with the last EC Monthly prognosis, albeit the latter sees (sizeable area of) HP becoming more dominant to SW/W, whereas the UKMO model favours anticyclonic conditions establishing more centrally across the UK. So, moderate confidence now in this sort of benign outcome by mid-month, but very little confidence on associated temperature regime (given divergent signals for the block positioning). Either way, some increasing optimism for a more settled, drier story emerging by mid-March but insufficient confidence, for now, to get too excited by it just yet.

 

Thanks fergie. Be interesting to see tomorrows EC32 update.