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

[Interitus]

Not an exact science of course but when GEFS constantly shows the pressure rising in Iceland in far FI at >1005 average (with the OP normally much higher) there is often something in it in terms of HLB possibilities. Too early yet but the first time for quite a while this winter I've seen it.

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There may be something in it however the average March SLP is just above 1005mb as can handily be found from NAO datasets, so the charts just show scatter around the mean, and if anything generally lower.

Edited February 24, 2015 by Interitus

[IDO]

Lest we forget a frigid wnw flow that brought decent snowccover to parts of nw england late jan ???

That was one of the coldest non polar norwesters I can recall.

Hi

Only one day has the high daily temp in Manchester fallen below 4c this Feb. the average high for Manchester this Feb is 6.25c. It is pushing it to say that is not run of the mill IMO for temps. The average snowy days is seven and I suspect that will not be passed by the end of the month. Compared to parts of the U.S. where they are still expecting PV reloads this and next week I think it is clear this winter has been a non event for many, though the usual suspects have, as I would expect, some snowy days. The Jan NW'ly was a taste of winter for some but it didn't really register on my radar and as they say, one swallow does not make a summer.

[winterof79]

Lest we forget a frigid wnw flow that brought decent snowccover to parts of nw england late jan ???

That was one of the coldest non polar norwesters I can recall.

Quite blue.Not just for the N/W either.More central northern areas had snow laying for a good while.This week seems restricted to areas north of Yorkshire.

March may be shaping up to be below average by a bit.As ever though,we have to see it come in to more reliable territory.

[johnholmes]

meantime the sometimes maligned 500mb anomaly charts, not consistently with one another, the EC has had various ideas on a similar theme with GFS a bit more consistent and NOAA 6-10 the most consistent of all 3 (as it often is). The NOAA 6-10 is shown below and seems to suggest to me a fairly strong Atlantic flow at 500mb from mid N America with heights over the UK a shade above normal so never that cold. Probably fairly changeable or unsettled even with switches from one weather type to another. The far south seeing less of this but still liable for an occasional outbreak of changeability.

No deep lasting cold and no major sign of lasting warmth. typical late February to early March really? Nor does the MJO give any support to lasting cold. It is probably too late for the MJO as we get to a season change to be all that helpful anyway.

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

[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 chilly Westerly flow across the UK will slowly become less cold as a series of frontal troughs cross over from the West through tonight and tomorrow.

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

MODELS-2 WEEK HEADLINE Changeable and windy with rain at times and hill snow across the North especially at first. Possibly brighter and drier from the South later.

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream Ensemble Forecast shows a strong West to East flow across the Atlantic through this week before it weakens somewhat as it moves back more to the North of the UK later in the period.

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

GFS OPERATIONAL The GFS operational today shows a very changeable week ahead with the emphasis slowly shifting away from rather cold conditions later this week to milder westerly winds, still quite strong at times with rain at times too for many. through the second week a shift to High pressure from the South dries things up generally but as this shifts to the NE and pressure builds to the nW a cold and unsettled pattern is shown to develop later.

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

http://www.wetterzentrale.de/pics/Rtavn3841.gif
 
THE GFS CONTROL The GFS control run is quite similar in the shorter term with rain at times in fluctuating temperatures but less keen on developing a colder theme later with High pressure then shown over Europe with a ridge to Southern England making the South drier and rather cold for a time and without the rise of pressure to the NW that the operational shows unsettled, windy and milder conditions look likely for the NW.

THE GFS CLUSTERS The GFS Clusters this morning look very undefinitive as a mix of options are shown between High pressure to the SW or West to a more unsettled West or SW flow for all with rain at times and High pressure further away to the South or SW.

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 again shows an unsettled and changeable period throughout its run this morning with rain at times on brisk Westerly winds for all and brief colder phases with showers, wintry on hills over the North.

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

THE FAX CHARTS The Fax Charts this morning show a series of troughs crossing the UK over the next 24-48hrs with spells of showers then rain and milder air briefly. Then a cold front crosses the UK from the NW on Thursday with further rain the colder air again before further milder and unstable air returns from the West on troughs over the weekend.

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

GEM GEM this morning shows a period of storminess developing early next week following this weeks changeable mix as fast moving vigorous Lows move East over or to the North of the UK. Then towards the end of the run High pressure builds quite quickly from the SW with more settled conditions developing for many by 10 days time.

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

NAVGEM NAVGEM maintains it's theme from yesterday showing a strong Westerly flow across the UK through the next week with some milder weather at times but with colder interludes too with showers turning wintry over the hills at times.

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

ECM ECM this morning shows the same basic theme though with some differentials these mostly focusing on the end of the period when the build of pressure from the South and SW is coupled with rising pressure over NE Europe which could lead to a chilly if dry period as we move forward from the end of the run towards next weekend.

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

ECM 10 DAY MEAN The 10 Day Mean Chart shows a strong build of pressure towards Southern Britain coupled with High pressure over Eastern Europe too. How these two features interact later is up to debate but for now it provides dry and brighter conditions than for some while for many with any rain confined to the far NW

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

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend towards drier and more anticyclonic weather later in the period is maintained with small nuances between output on how this transpires.

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 97.5 pts followed by UKM at 97.1 pts and GFS at 96.4. At 5 days ECM  continues to lead the field at 90.0 pts over UKMO at 88.1 pts and GFS at 86.2. At 8 days ECM remains the leader with 63.6 pts over GFS's 58.7 pts. Then at Day 10 ECM retains superiority at 46.3 pts over GFS at 41.9.

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 The theme of drier weather shown between the output remains for later in the period with the current unsettled and changeable conditions contiuing for around another week with the same day to day fluctuations in temperature remaining a feature amongst the rain and showers at times plus some wintriness at times over Northern hills. Then more interestingly there are strong signals emeging of drier weather moving first into the South of the UK and probably extending further North later. How this transpires synoptically is yet to be pinned down but it looks like a High lying close to the South will bring benign and dry conditions in temperatures largely close to average by day wuth the risk of patchy frost at night as winds look like maintaining something of a Westerly element at this time. All this while pressure is also becoming High over Eastern Europe and some output acknowledges this in hinting that the Southern UK High could become absorbed by this in some way which could give rise to something of a continental feed into the UK later and if this transpired would lead to colder conditions across the UK in SE or East winds. All a long way off to take very seriously at the moment but it is something that is been shown in a minority of output in recent days and should be watched with interest. However, I'm sure there will be much waxing and waning on this scenario over future model output and in any event it all seems a million miles away yet given that we have definately got at least another week of Atlantic volatility looking likely before any of that happens. So summarising unsettled and changeable over the next week or so with rain and showers and temperatures near to or occasionally a bit below and above average before more settled conditions arrive from late next week with a cessation in the amount of wind and rain for most and more in the way of sunshine by day and possible frosty nights.  

Issued at 09:00 Tuesday February 24th 2015

[mushymanrob]

easterly what easterly?...

 

when the gfs shows something in fi, and these charts (this run has been consistent in suggesting a gradual pressure rise in the southwest as the azores high drifts closer) dont...i know which data i believe will be proven to be more accurate.

of course alot of the gfs's fi mid/high latitude blocking in so deep in fi that it might not show on these charts yet.

but until they do (and IF they do) then these phantom fi easterlies arent really worth thinking about as theres more to suggest they wont happen, then that they will.

but just supposing they do... and it is possible and common for an easterly in march, without the deep draw that happened two years ago i suspect itll be nothing more then cold for colds sake.... just prolonging this lacklustre winter. not delivering the snow (i believe) most coldies desire, just grey stratus benign gloomy (like march 69).

 

 

[knocker]

This morning's anomalies are not looking at any sustained build up of heights ti the NE. Both the GEFs and ECM toy with ridging just to the south east of the UK with a weak trough Scandinavia to eastern Med. and HP eastern Europe. Surface analysis of this is the HP to the south (westerly flow) with cut off trough eastern Med and LP to NW of UK. The ext period tends to retrogress the HP more to the SW. Temps around average, perhaps slightly above and it would appear typical March scenario.

The EC32 tends to support this although there is a suggestion of more of a height build up the NE around T432 but would probably just mean the HP more centred over the UK before reverting to more zonality with the HP to the SW

Charts courtsy weatherbell

 

Michael Ventrice â€@MJVentrice 

12Z ECMWF EPS keeps the high latitude North Pacific blocking established in the 11-15d. Prolonged winter as a result.

Edited February 24, 2015 by knocker

[Weather-history]

Some of the charts next week do remind me somewhat how March 1995 started off. UKMO 0z even has a potential runner on it, like what happened in early March 1995.

Edited February 24, 2015 by Weather-history

[winterof79]

easterly what easterly?...

 

814day.03d.gif

when the gfs shows something in fi, and these charts (this run has been consistent in suggesting a gradual pressure rise in the southwest as the azores high drifts closer) dont...i know which data i believe will be proven to be more accurate.

of course alot of the gfs's fi mid/high latitude blocking in so deep in fi that it might not show on these charts yet.

but until they do (and IF they do) then these phantom fi easterlies arent really worth thinking about as theres more to suggest they wont happen, then that they will.

but just supposing they do... and it is possible and common for an easterly in march, without the deep draw that happened two years ago i suspect itll be nothing more then cold for colds sake.... just prolonging this lacklustre winter. not delivering the snow (i believe) most coldies desire, just grey stratus benign gloomy (like march 69).

Your chart shows the MLB in exactly the same place as GFS for that timescale.The Development of the afore mentioned is what could be of interest in that it migrates eastward on the model output further down the line.

 

 

All open to debate and may not happen but worthy of discussion all the same.

Edited February 24, 2015 by winterof79

[winterof79]

No hook up to Scandi this run though so far.

 

 

The 00z ensembles have a good cluster cold towards the end.

[Winter Cold]

I agree Frosty. Its been fun watching the GFS consistently play about with height rises to our NE. The 0z continued on from yesterday with it this morning, and although the 6z doesnt quite make it, as you say it would probably go that way if it went on further.

 

We then have ECM showing rising pressure to our north/east this morning for the first time.

 

Its nice to see anyway, and who knows, there is obviously a fairly strong signal for it to keep being shown. Ill be watching with great interest in the next few days to see if we can count it down in the runs to more reliable time frames

[Captain Shortwave]

The trend is still the same for week 2 with pressure building over the south of the UK

Reflected in the ECM ens too

So I think the Azores ridge into the south of the UK will likely verify, the bigger question is how the build of pressure into the rest of Europe pan out given there are lower than normal heights over south east Europe. Can we get a ridge building over northern Europe where we see the Azores ridge and Russian high link up, or will we end up with low heights continuing to drop to our south east and keep a more changeable theme, albeit with drier than normal conditions prevailing, especially for the south.

 

For the record the 06z GFS shows no real blocking, I suspect there was a data transfer error on that chart Frosty as the 11th March looks like this on meteociel

Edited February 24, 2015 by Captain shortwave

[mushymanrob]

Your chart shows the MLB in exactly the same place as GFS for that timescale.The Development of the afore mentioned is what could be of interest in that it migrates eastward on the model output further down the line.

 

 

All open to debate and may not happen but worthy of discussion all the same.

 

ah yes, but you have quoted the 06z gfs which has dropped the mid/high latitude blocking the 00z suggested along with its associated easterlies. sorry i should have posted the gfs 00z charts for that timescale that did illustrate my point.

i agree that the 06z is in line with the 8-14 day anomaly chart i posted earlier, both of which dont suggest the easterlies and scandi block previous runs had.

of course the high might migrate to scandinavia, and produce easterlies, but its unlikely in the next 10 - 12 days or until the noaa chart suggests pressure build up that way.

[Frosty.]

The trend is still the same for week 2 with pressure building over the south of the UK

Reflected in the ECM ens too

So I think the Azores ridge into the south of the UK will likely verify, the bigger question is how the build of pressure into the rest of Europe pan out given there are lower than normal heights over south east Europe. Can we get a ridge building over northern Europe where we see the Azores ridge and Russian high link up, or will we end up with low heights continuing to drop to our south east and keep a more changeable theme, albeit with drier than normal conditions prevailing, especially for the south.

For the record the 06z GFS shows no real blocking, I suspect there was a data transfer error on that chart Frosty as the 11th March looks like this on meteociel

It was a howler of a mistake by me captain, that 6z chart I posted was from yesterday's run, but anyway, I agree with winter cold, I still think there is a good chance of an easterly in March. Edited February 24, 2015 by Frosty.

[summer blizzard]

A lovely run from next week onward on the 6z..

 

[stodge]

Yet what are we to make of this from the 12Z Op:

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015022412/gfs-0-144.png?12?12

 

Quite a nasty little storm to greet the new month.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015022412/gfs-0-186.png?12?12

 

The following storm, however, slows down and deepens to the south of Greenland encouraging the pressure rise to the British Isles though perhaps less convincing on the 12Z than the 06Z.

[Summer Sun]

Yet what are we to make of this from the 12Z Op:

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015022412/gfs-0-144.png?12?12

 

Quite a nasty little storm to greet the new month.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015022412/gfs-0-186.png?12?12

 

The following storm, however, slows down and deepens to the south of Greenland encouraging the pressure rise to the British Isles though perhaps less convincing on the 12Z than the 06Z.

 

UKMO is nowhere near as deep with the low at t144

 

 

GEM though is closer to GFS at 965mb

 

 

Need to wait and see what ECM comes up with later on

[Man With Beard]

Looking at the latter stages of GFS, I feel a spring-watch coming on. Sunday 8th March represents a SW flow which, if winds remain above calm, can lead to early season warmth. Perhaps a 16C could be squeezed out of the chart for that day in the south. Long long way to go of course.

[Gael_Force]

All these high pressure charts seem to be stuck out at 200 hours. We were supposed to be seeing high pressure for the start of March....this weekend....it's been postponed!. For days the GFS has been playing around with HLB at the end of the runs .....it's not moving forward in time!

 

If the pattern over the US doesn't shift, what's the betting that the weather will still be westerly and unsettled two weeks from now?

[Polar Maritime]

Northern Ireland and N/W Scotland could be in for a rough ride for the turn of the new Month, 'if' the GFS became reality. With heavy rain and severe gales giving blizzard conditions and over high ground over the spine of the country, As cold -7/-8 uppers get pulled in with a biting wind chill. Would make for a very interesting period of weather..

 

Edited February 24, 2015 by Polar Maritime

[Eugene]

All these high pressure charts seem to be stuck out at 200 hours. We were supposed to be seeing high pressure for the start of March....this weekend....it's been postponed!. For days the GFS has been playing around with HLB at the end of the runs .....it's not moving forward in time!

 

If the pattern over the US doesn't shift, what's the betting that the weather will still be westerly and unsettled two weeks from now?

 

Yep spot on and after looking at the 12Z ensembles next mid weeks ridge is flattened by more atlantic lows.

 

That direct westerly early next week is very impressive with 850's just as cold as a direct northerly, very rare indeed, wonder what repurcussions the deep cold weather over that side of the atlantic has on our weather, more wet and windy weather no doubt.

[IDO]

ECM maintains it's recent theme in FI of building heights:

 

D8:   D9: D10: 

 

Hopefully its not the ECM up to its old tricks again! For instance the GEM is not buying it:

 

 

It does have some support from the GEFS but there are other clusters so I am not sure the models have resolved D8 plus yet, though I suspect a continuation of the current quasi zonal spell is less likely than a build in  pressure from the south. The GEM D16 mean from this morning going that way:

 

 

 

[legritter]

Interesting charts this evening ,nice to see some low 850mb temperatures being forecast on different models .still i,m sure if we can get a bit of luck, March could deliver [i will take whats on offer and hope for an upgrade ] .lets hope the back end of winter early spring is our cold weather friend .

[Winter Cold]

Early March still looks like starting on the cold and wintry side, with ECM sticking to its guns for a few days of -5 to -8 T850s. Its nice to see GFS also displaying similar values. Few charts below from tonights ECM:

 

 

 

ECM still playing about with throwing ridges up towards the end aswell, following on from its 0z run. GFS has returned to the playground aswell, after its brief departure on the 6z. As has been said, not much movement forward in time frame yet, however its still reasuring to see the signal remain if your a coldie

[mushymanrob]

Been some low 850's this week and theyve failed to produce anything too unpleasantly cold, so ive no reason to suppose IF nextweeks predicted 850's come off they will produce anything other then a normal chilly fresh early spring weather type. The predicted temps are notoriously inaccurate that far out.