Model Output Discussion - Spring 5th March Onwards 6z--->

[stodge]

a pleasant calm week?...

luck will play a part, as spoiling cloud could well rob us of any pleasant sunshine, but at least its looking dry. the old double edged sword will raise its head too... sunny days could lead to frosty nights. i note that the current expected 'uppers' arent too mild so it could be chilly.

 

note the noaa 8-14 day chart suggests a flattening out of the upper air flow

 

814day.03.gif

 

this would suggest the gfs 00z 's fairly atlantic dominated run would most likely verify

 

The GFS has played the return of the PV and the Atlantic at the end of the month as a theme for several days and it's getting impossible to ignore.

 

I do wonder if it is, as we have seen at other times this winter, a response to changes in the stratosphere. We see a brief warming of sorts leading to amplification which then breaks down to a reset with the PV heading back to Greenland/NE Canada and the Atlantic firing up for a period before the next amplification.

 

Signs on the extreme FI of the 06Z Operational output of the PV finally relenting right at the end of the month so a 7-10 day period of Atlantic dominated weather before the next change triggered by the final warming which is being well advertised.

[Frosty.]

6z shows mild weather returning to the south / se on Tuesday and Wednesday but cooler further north and west but by the second half of the week, it looks more pleasant / benign nationwide with light winds and more in the way of sunshine but nights look cold where it's cloud free, the fine weather lasts into next weekend, at least further south but week 2 is trending more unsettled with the Atlantic really cranking up through low res so it could be an unsettled run up to Easter.

[Milhouse]

The GFS 12z is actually a decent run for delivering some fairly high temperatures under high pressure. Pressure building throughout next week, then declining from the north during next weekend. Becoming rather pleasant too.

 

 

What is for sure is high pressure will be not too far from the UK throughout the next week, The GFS 12z has it in the ideal position for some pleasant conditions. The ECM has the high further west allowing fronts and cooler air to slip down from the north.

[Frosty.]

The Ecm 12z shows two pulses of cold air from the NE / North with a risk of wintry showers and the outlook turns increasingly unsettled from the northwest, before all that there is a window of fine and pleasant weather before it turns more unsettled at the end of the week although it does briefly settle down again in the south for a day or so. The run up to Easter looks more likely to be unsettled than settled with the Atlantic cranking up and with a nw / se aligned jet, further cold incursions would be likely.

[KyleHenry]

The Ecm 12z shows two pulses of cold air from the NE / North with a risk of wintry showers and the outlook turns increasingly unsettled from the northwest, before all that there is a window of fine and pleasant weather before it turns more unsettled at the end of the week although it does briefly settle down again in the south for a day or so. The run up to Easter looks more likely to be unsettled than settled with the Atlantic cranking up and with a nw / se aligned jet, further cold incursions would be likely.

Agreed it all points to cool wet and windy last ten days of March. Grim is the word that comes to mind.

[Winter Cold]

Evening model watchers!

 

 

Well the ECM continues to be the worst scenario of the big 3 tonight as its the most west with the high next weekend and brings in cooler, showery air:

 

  

It has the UK under sub zero uppers throughout the run pretty much!

 

 

The UKMO is an improvement on this mornings run, holding onto higher pressure into Saturday:

 

 

 

GFS strongest with the ridge:

 

 

 

Looking further ahead, then the GFS isnt showing what most would like to see im afraid, with a distinctly cool an wet run up to Easter and end of month:

 

     

Edited March 15, 2015 by Winter Cold

[ANYWEATHER]

Nothing spectacular in the days ahead with both ecm and gfs show high pressure in some format in control, Day to day forecasts will prove difficult in the days ahead. From t+168 they both show The Atlantic comes steaming in.....

[Frosty.]

Agreed it all points to cool wet and windy last ten days of March. Grim is the word that comes to mind.

It's normal early spring weather and it's not all doom and gloom, we have fine pleasant conditions just around the corner and even when it turns more unsettled there will still be some dry and sunny weather too but there is something for coldies, if there are any left? and also for those who prefer milder.

Edited March 15, 2015 by Frosty.

[Polar Maritime]

GFS & ECMWF both continue to show a cool/unsettled Pm flow from the 24th. With a wintry mix over high ground.

 

Edited March 16, 2015 by Polar Maritime

[IDO]

No sign of a return to anything unsettled in the reliable time frame and March continues to be very dry and above average temps as a whole for the south. The London temp graph suggests no rain in the next 8 days with temps average to just below:

 

 

It is after D8 that the models hint at a change, as the Scandi heights sink and the jet move further south. The GEFS MJO has been consistent of a dying signal in phase 7, so a return to zonal or quasi-zonal looks likely:

 

 

The GEFS after D10 hints at a return to baby ridge & troughs in a mobile westerly flow so for the south rain should not be too significant and a return to mild and cooler PM and TM flows. Nothing from the ECM or GEM to suggest anything too different to the GEFS. ECM suggests colder 2m temps for later this week but I am not sure they will be that cold. Last night they were forecasting 8c for Friday but UKMO are currently suggesting 11c:

 

 

Looking at the GEFS mean uppers and comparing them with the ECM op suggests the latter are probably overdoing them:

 

 

 

So pretty much a normal mix of average March weather. Certainly no late wintry period, all the pre-winter signals were off the mark for our region. No prolonged early Spring warmth either, but the next best, with a nice settled period for the S/SE. The CET was +1.3c for the first half of March so clearly above average but that includes only a few warm days.

Edited March 16, 2015 by IDO

[johnholmes]

The detail to be decided of course but both NOAA 6-10 and EC show a pretty similar idea with GFS at times also joining the same idea.

As Frosty suggested last evening, pretty normal fare for early spring. 

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

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

and the 8-14 NOAA

still with the ridge in the Azores area and a fairly westerly upper flow across the Atlantic into the UK. So perhaps a sort of NW-SE type split with the more settled weather occurring more often in the SE area.

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 08:00 ON MONDAY MARCH 16TH 2015.

 

THE CURRENT GENERAL SITUATION A cold but slack East to NE flow will continue to affect all areas weakening tomorrow with a ridge over Scotland slipping slowly South.

 

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

 

MODELS-2 WEEK HEADLINE A lot of dry weather with some sunshine and just occasional rain moving down from the North later. Temperatures will be close to average or a little below overall.

 

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream Ensemble Forecast shows the flow well away to the West and North of the UK currently. It then steers South close to Western Britain as UK High pressure builds late in the week. Thereafter the general theme is for the flow to strengthen across the Atlantic and surge East across the UK in week 2 with ony a slow relaxation North late on.

 

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

 

GFS OPERATIONAL The GFS operational run doesn't differ much from yesterday with the continued theme of this week being governed by High pressure across the UK from midweek. With time this is then shown to recede South and SW opening the door to Atlantic Westerly winds and lower pressure with rain at times extending to all areas on occasion in temperatures close to average

 

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

 

http://www.wetterzentrale.de/pics/Rtavn3841.gif 

 

THE GFS CONTROL The GFS control run shows a very similar scenario through the period with the same drift towards more unsettled and windy weather in Westerly winds and rain at times next week.

 

THE GFS CLUSTERS 90% of the GFS clusters show Westerly winds two weeks from now with variations in degree of extent and influence from Low pressure likely to lie close to the North of the UK. Only 10% of the pack indicate High pressure close enough to the South to cut off the influence the Westerly winds have and restricting then to the North only.

 

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 High pressure close to the UK from midweek. A weak trough is pulled South in the flow setting up another day or so of chilly NE winds across the South before the High pressure in the NW slips South across the South with weak Atlantic troughs affecting the North next weekend. 

 

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

 

THE FAX CHARTS The Fax Charts show High pressure well in control of the UK weather this coming week with variable cloud cover, some sunshine especially midweek before the later charts show more influence from Atlantic troughs affecting the North by the start of next weekend as the High recedes to the SW.

 

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

 

GEM GEM today shows quite a chilly feel to it as our current rather stagnant pattern which lasts much of this week turns more and more into a rather cold pattern under Northerly winds and wintry showers with sharp night frosts next week as High pressure sits in cold air by then just to the West.

 

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

 

NAVGEM NAVGEM too keeps a cold feel about it as a High pressure ridge is maintained across the UK in one shape or another. The positioning and influence of that is determined by the shuffling of weather systems over Europe with spells of chilly and cold NE winds enhanced at times especially in the South with some wintry showers possible later in the East and SE. 

 

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

 

ECM ECM this morning shows a High pressure ridge later in the week across the UK with fine and bright conditions but still with a chill NE wind across the South enhanced again for a time. As we move through next weekend and the new week the trend is for the Atlantic Westerly winds to return are shown with rain at times especially in the North at first but perhaps more generally by the end of the 10 day period. 

 

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

 

ECM 10 DAY MEAN There is strong support now from the ECM model members that in 10 days times we will lie under a westerly feed of air between Low pressure South of Iceland and High pressure near the Azores with a typical early Spring changeable weather pattern for all.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The collapse of the European High next week is still well supported with the evolutions thereafter maintaining a tendency for Atlantic Westerly winds and rain at times to develop slowly next week especially in the North.

 

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 97.8 pts followed by UKM at 97.3 pts and GFS at 96.6. At 5 days ECM  continues to lead the field at 91.2 pts over UKMO at 88.6 pts and GFS at 87.4. At 8 days ECM remains the leader with 66.6 pts over GFS's 60.6 pts. Then at Day 10 ECM retains superiority at 49.6 pts over GFS at 45.7. 

 

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 Not much new to talk about this morning from the outputs that hasn't been covered by me in previous reports as the pattern seems locked in the quiet High pressure based pattern this week with sometimes leaden skies and drizzly rain mixed with brighter and in places sunnier, milder weather with some sunshine especially midweek. Then the slow trend towards more unsettled and Atlantic based weather next week develops. There are of course differences within the models on how the more unsettled pattern evolves with the majority going for a straight Westerly delivering rain and showers in a typical March setup while a slightly fewer number show more of a NW or even Northerly airflow develop later with attendant wintry showers and frosts at night. The general theme though from the Euro's is that the former pattern will be more likely with some strong Westerly gales at times in the North to accompany the rain from depressions South of Iceland. It may also be that the South will see the least effects from this pattern though it looks likely that even here will see some rain next week. All in all though a lot of fine weather still to come before things turn more traditionally unsettled. Having said that there is nothing dramatic shown again this morning and given the time of year conditions won't be terribly exciting weather wise with Spring proper (i.e sunny and warm) still a little way off beyond the parameters of the current output.   

 

Issued at 08:00 Monday March 16th 2015

[BlueHedgehog074]

GFS & ECMWF both continue to show a cool/unsettled Pm flow from the 24th. With a wintry mix over high ground.

 

Interestingly, both the anomaly charts below - the 'ECMWF/GFS 8 to 10 day mean' and the 'NOAA 8 to 14 day 500mb chart' - are in fairly good agreement for a cool(ish) Atlantic set up to take over. Lower than average heights generally dominating to our North and North-West with higher than average heights close by to our South and South-West. While nothing particularly cold and blocked looking likely, the flow, at the 500mb level, seems to be between the West and North-West on the charts. As such, does appear to suggest the possibility of a Westerly dominated pattern generally leaning towards cool, polar, air getting into the mix at times. Some slight differences between each chart, such as the GFS 8 to 10 day mean (to the right on the first image below) having the higher than average heights to the South/South-West being a little more influential over Southern UK. This of which could also mean the worst of any unsettled weather being a bit more concentrated towards Northern UK, otherwise, again, quite good confidence from the charts to see a Westerly outlook take over.

Before then, it looks as though the cloudy, cool, Easterly the Scandinavian High has provided will start to lose its power. Brighter and milder weather looking to take hold over the UK as the Azores High Pressure ridge builds over the UK during mid-week. Looks as though Spring will be trying to fight 'Winter' away from the British Isles.

Then seems likely low Pressure will drop down towards Scandinavia with some troughing developing to our East. This of which may provide a brief cold Northerly over the UK should it back far enough West before the UK/Atlantic ridge topples Eastwards and cuts off the Northerly/North-Easterly flow. Admittedly, out of all the charts, the ECMWF is probably the best chart this morning for this possible brief Arctic plunge for the early weekend.

Maybe cold enough for a few odd sleety showers, most especially over the hills and over to the East (for those that want it) should the likes of the ECMWF be handling the outlook correctly (but wouldn't completely bet on it). Either way, some brief flow between the North and North-East does seem quite likely towards the end of this week.

[stodge]

The GFS 06Z output continues the theme of a strong Atlantic at the end of the month possibly as an initial response to the final stratospheric warming over Asia pulling the remnants of the PV back to its "normal" Greenland/NE Canada home. A procession of LP passing just to the north of Scotland but the emphasis possibly more on PM rather than TM air.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015031606/gfs-0-288.png?6

 

Very typical - ridge, depression, ridge. Another coldish plunge to the NE of the USA right at the far end of FI but also perhaps a sign of the final weakening of the PV - we'll see.

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

 

AO trending back positive - indeed a few members saying quite strongly so - after a negative spell this week suggesting the Atlantic-dominated spell is set but a huge spread by the end of the month so a lot of options on the table and a suggestion the Atlantic-dominated spell might only be 7-10 days.

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

 

Likewise, the NAO, after a dip to near neutrality, goes positive again but a big spread among the members so, as you'd expect, plenty of options to end the month.

[Newberryone]

The general consensus re a gradual breakdown towards the end of the month does seem to be gathering momentum in the model output today.

However, with pressure still relatively high towards the southwest in FI, I wouldn't be in the least bit surprised if this change doesn't be downgraded somewhat in the coming days.  

[Frosty.]

6z shows a good recovery in temperatures in the south by tomorrow and wednesday with 12-13c compared to today's chilly 7-8c and there will be more in the way of sunshine, temperatures slower to recover further north and west but they do improve as this week goes on, however, later this week the orientation of the high changes and winds go around to NEly which draws colder and cloudier weather across the east in particular but by the weekend it turns milder and brighter again. Low res becomes more unsettled as the northern arm of the jet strengthens.

[Summer Sun]

The high is hanging on slightly longer on this run compared to the 06z

 

12z

 

 

06z

 

 

The low does break through in the end

 

 

GEM updating slowly and longer term it also shows the high lasting longer than previously shown

 

Edited March 16, 2015 by Summer Sun

[Man With Beard]

Been away from this board a while - just too busy - but doesn't seem much is changing. Spring has definitely forgotten to show up aside a couple of days last week, and I wonder if March may squeeze in below average. The winter tendency for the Azores high to hang back to the west looks set to continue, and in tandem with a strengthened trough the the northeast, it looks set to stay on the cool side for quite some time. For the whole of Europe, too, right down to the Med

[stodge]

http://meteociel.com/modeles/ecmwf/runs/2015031612/ECM1-120.GIF

 

That wouldn't be warm for lowland East London in truth.

 

http://meteociel.com/modeles/ecmwf/runs/2015031612/ECM0-144.GIF?16-0

 

A chilly Sunday you'd think as well.

 

http://modeles.meteociel.fr/modeles/gem/runs/2015031612/gem-0-120.png?12

 

GEM - very similar.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015031612/gfs-0-120.png?12

 

GFS - much more benign with a lighter NE'ly for my corner of the world.

 

http://meteociel.com/ukmo/runs/2015031612/UW120-21.GIF?16-18

 

UKM sides with ECM and GEM so looks like a chilly weekend for the SE.

 

Longer term the Atlantic comes in as you might expect.

[Frosty.]

Ecm 12z shows colder air slowly pushing south at the end of this week but most of this week will become milder and more pleasant with increasing amounts of sunshine and lighter winds. One thing I've noticed with the 12z runs is a less unsettled FI, nothing like as unsettled as earlier runs today, the lows don't look as deep and they are further north. Today's met office updates painted a very unsettled outlook but it doesn't look bad to me.

Edited March 16, 2015 by Frosty.

[mushymanrob]

Spring has definitely forgotten to show up aside a couple of days last week,

Not so sure about that sir, whilst warmth and sun might not have been overly evident so far march has been pretty normal, and could have been alot worse.

[ANYWEATHER]

High pressure in some format rules the roost in the near time frame , devil in the detail, but just like today forecasting tomorrow is proving difficult , and judging by the whole of the model output, Spring will take some time to Spring    

[Milhouse]

Not so sure about that sir, whilst warmth and sun might not have been overly evident so far march has been pretty normal, and could have been alot worse.

 

Indeed. The CET is round about average at the moment so you cant really get a more typical start to Spring than we have had. The models are painting a very nondescript and average outlook tbh. Cloudy and cool for some with the odd milder day mixed in. Some Spring sunshine too.

[mushymanrob]

Indeed. The CET is round about average at the moment so you cant really get a more typical start to Spring than we have had. The models are painting a very nondescript and average outlook tbh. Cloudy and cool for some with the odd milder day mixed in. Some Spring sunshine too.

 

not overly wet either, mostly quite dry.... i dont look upon the current charts as ones that lack early warmth so much as ones that doesnt return us to winter weather which is very common in march...

if we pick up the westerly upper flow the noaa 8-14 dayer suggests then march looks like 'averageing out'... with no real extremes of warmth or cold.

[IDO]

The trend from yesterday's 0z is to extend the higher pressure over the UK. This morning both ECM and GEM still have HP in charge at D10 for the south:

 

 

 

The GFS & GEFS are not so keen, with a similar theme to yesterday from D9-13. Though again the next 8 days in the S/SE still looks dry with temps just below average as a whole:

 

 

The mean 850s follows the seasonal average for the next 16 days so no sign of any late cold or early warmth:

 

London Aberdeen: 

 

Looking at the GEFS in FI and there is no signal for an extended zonal washout. In fact the opposite is the current signal with HP beginning to become more dominant again. Early days but its good to see no wet or cold weather as we see the Easter period coming into the GEFS:

 

D16 mean;

 

With the strong MJO forcing, the Pacific jet is flattening the omnipresent Pacific Ridge so the winter pattern is finally countered. Upstream a mobile de-amplified pattern which with the PV hopefully moving towards a sleepier mode will give the Azores a chance to influence our weather for a benign warmer setup as we enter April. The CFS mean anomaly for April is looking promising in that direction:

 

Edited March 17, 2015 by IDO