Model Output Discussions 12z 03/05/2016

[Captain Shortwave]

At this stage there seems to be two good solutions and one bad solution on offer here.

Good 1 - the low zips westwards across the south of the UK which allows a renewed push of heights to build through France and into the UK resulting in a south of east flow with temperatures pushing into the mid-twenties, we do however face a potential washout day which could end up being bank holiday Monday. The 06z GFS showed this quite nicely, the 12z not so bullish about this.

Good 2 - The low stalls and fills somewhere near Germany which means it barely affects the UK, though there could be a rather brisk NE wind across eastern areas for a time.

   

Bad - The low moves across the UK and then stalls which is what the UKMO is suggesting.

   

Saying that even the UK would probably result eventually in a slack, showery and warm picture but of course we could see a couple of days of persistent rain as fronts move slowly across us.

Still looking very messy with uncertainty arriving as soon as Sunday which is only 3 days away.

 

Saying that the ECM ens look decent

      

Upper ridge through the UK, though the surface high being north of the UK would result in an east/north east feed which could leave NE England and Eastern Scotland rather grey at times, especially near the coast.

Edited May 26, 2016 by Captain Shortwave

[northwestsnow]

24 minutes ago, Scorcher said:

What sort of evolution would you expect then? 

GFS/UKMO/BBC all have the trough in or over the UK 120 - 144h, only the ECM looks settled, i hope its right of course!

[knocker]

The 6-10 anomalies tonight all agree on high pressure being in charge with the GEFs perhaps hinting at a possible intrusion of an unstable low pressure area that might impact the south.Temps a little above average.

In the 10-15 period a continuation of the ridging into Iceland with the Atlantic trough to the west although towards the end of the period indications that the ridge breaks down as the trough gains more influence and a more zonal regime sets in.

Edited May 26, 2016 by knocker

[len]

4 hours ago, knocker said:

I see the the GFS has retarded the movement west of the low a tad

Please Knocker (or anyone) can you direct me to these charts?

Thanks. Len

[knocker]

Just now, len said:

Please Knocker (or anyone) can you direct me to these charts?

Thanks. Len

Sorry Ien no can do they are behind a paywall.

[Singularity]

1 hour ago, northwestsnow said:

GFS/UKMO/BBC all have the trough in or over the UK 120 - 144h, only the ECM looks settled, i hope its right of course!

The 22:45 update was, thankfully, a consideration of the range of possible outcomes for BH Monday, stating that it could be anything from soaking wet to warm and dry, depending on how far west the 'angry area of rain' advances.

Longer term, a picture is emerging of something akin to a split polar vortex scenario in winter, except of course at this time of year it's just two surface lows divided by cross-polar ridging.

While that ridging may be dire for the Arctic sea ice, it appears that it might actually be aligned favourably to bring dry, warm(or at least a little above average) conditions to much of the UK, depending on the position and alignment of troughs in the North Atlantic and Europe.

  

Helping with the temperatures is the fact that Scandinavia is set to be flooded with relatively warm air by Monday, this then feeding across during the following days - the pace of this depending on how that troublesome low from Europe behaves. ECM's solution, holding it across Germany, is the best for achieving a warm easterly, though the setup does threaten some cooler, murky conditions for eastern coasts - the North Sea SSTs are largely near or a shade above average so fairly typical early summer onshore wind conditions can be expected.

Both ECM and GFS are suggesting that the broad trough near the Azores will be with us for the next 10-14 days and perhaps beyond, as new lows spin in from North America. They also indicate some progression east, which helps to locate the mid-latitude component of the cross-polar ridge across the UK rather than to the west. Hopefully this will come to pass, i.e. we avoid the toning down of west-east progression that is so often seen with the models. Given that they are already showing so little progression, could we really see much more lost? Unfortunately, the reverse, retrogression, is all too much of a possibility. It just takes one of those lows coming off the U.S. losing momentum while still west of the Azores trough, and then drawing said trough toward it rather than moving into the trough and being assimilated.

So we can't rest easy on the early June prospects just yet. Let's just focus on getting that low to stay in Germany for BH Monday (my apologies to any German readers who come across this!).

[knocker]

A brief look at the latest EC32 means.

Firstly it slowly clears the area of low pressure to our east further east Weds/Thurs leaving ridging north over the UK to the main area of high pressure to the north.

This analysis lasts about a week until 8th as the HP to the north declines and the Atlantic trough to the south west becomes more influential although temps still holding up and continue above average.

From there until around the 20th after a brief ingress from the Atlantic there is a general trend for the Azores HP to push in from the south west again bringing some settled weather with temps still a little above average.

Back to the present. Monday and Tuesday continue to be quite wet over most of the UK with the METO currently pushing the front through a tad quicker than the GFS. This follows a pleasant weekend with perhaps isolated showers but quite warm with temps a little above average.

 

Edited May 27, 2016 by knocker

[mb018538]

ECM doesn't look bad at all again this morning, after the messy low disappears off the scene by the middle of next week, things settle down again with the trough stalled out to the west. 850s slightly above average, with temperatures in the sun in the 20-22c I would imagine. Not bad at all.

[northwestsnow]

Yes, i'm very happy with the 00z runs,

UKMO 144 http://www.wetterzentrale.de/pics/Rukm1441.html

Has moved away from the trough scenario quite nicely this morning, GFS brings plenty of settled warm weather and ECM looks good out to day 9 although i fear the trough in the Atlantic may try to break through but thats FI.

All in all aside from a couple of messy days early next week things looking pretty good ,yaaaaay!

EDIT By day 10 its warm for the UK but the trough still looks menacing, all in all though a pretty nice start to June,perhaps more so across the north and west initially away from the continental trough but then for most as the trough fills and moves away S.

Edited May 27, 2016 by northwestsnow

[Summer Sun]

Better from UKMO this morning with the high winning out still the risk of some rain / showers for the south with the trough close by but Midlands north should be fine

 

Highest temps would always be in the west where your sheltered from the NE'ly breeze

[johnholmes]

The NOAA and EC-GFS anomaly charts looking pretty similar to one another suggesting mostly settled dry weather for the UK in the 6-10 day period and probably extending beyond 10 days looking at the NOAA 8-14, perhaps a tendency to break down to a more unsettled flow from the SW by day 14, see below

http://www.cpc.noaa.gov/products/predictions/814day/500mb.php

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

The fine details of course will come from the synoptic model outputs with the usual possible changes at even short time scales, much as we are seeing as to how they are dealing with BH Monday details. But with an upper ridge dominant the vagaries of surface features may be less than usual until the break down. Just where the surface flow sits will decide if the east coast of the UK joins in with the rest of the country!

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 09:00 ON FRIDAY MAY 27TH 2016

THE CURRENT GENERAL SITUATION The basic story of High pressure to the North of the UK and Low pressure to the South looks like remaining for the next couple of days at least with slack and unstable winds from the East affecting the South in particular.

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

CURRENT SNOW FORECAST AND/OR FREEZING LEVEL OVER THE UK The freezing level and snow forecast is now suspended until the beginning of October.

http://www.snow-forecast.com/maps/dynamic/uk

http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow.gif

MODELS-2 WEEK HEADLINE Some thundery rain or showers at times but plenty of dry and fine weather too this especially in the North. Occasionally warm in the South.

THE GFS JET STREAM FORECAST The Jet Stream is expected to remain very slack over our part of the Northern hemisphere over the next week as Low pressure remains to the South of the UK and High pressure to the North. However, this morning there is a theme of moving the Jet Stream North and strengthening it in the second week as Low pressure finally repositions itself to the NW with higher pressure over Europe by then.

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

GFS OPERATIONAL The GFS Operational Run today shows High pressure maintained to the North of the UK over the next week or so with Low pressure over or to the South of the UK continuing to promote the best conditions for the North of the UK while thundery rain or showers affect the South at times. Then through the second week Low pressure builds North over the Atlantic and eventually allowing pressure to rise to the South and SE with winds swinging more to a SW or West direction with rain at times returning to the NW while the South and East slowly become largely dry with more intermittent rain while temperatures stay well up to normal or somewhat above in places.

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

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

GFS CONTROL RUN The Control Run disagrees with the Operational Run in the second week as it shows High pressure being maintained to the North of the UK with Low pressure to the South maintaining a largely Easterly feed across the UK with thundery showers at times edging up into Southern Britain at times even out to the end of the run.

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=144&mode=0&carte=0

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=384&mode=0&carte=0

GFS ENSEMBLE DAY 14 DATA The clustering today shows no dominating weather pattern likely to be present in two weeks time with most members showing very slack conditions across the UK with the risk of showers for some but no really unpleasant weather likely.

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 The UKMO model this morning shows Low pressure to the SE and High pressure strengthening further to the NW at the start of next week continuing to promote winds from a NE quarter, quite strong with time and continuing to bring the risk of some rain at times towards the SE and although some warm air around some cool weather too under any persistent cloud and rain and more generally near the East coast.

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

THE FAX CHARTS The Fax Charts main message this morning revolves around how much progress is expected into the UK from the East of Low pressure developing over the Low Countries on bank Holiday Monday. The current thinking is that the second half of Monday could be very wet in the East with a lot of uncertainty on how far West that travels before Monday's end. By Tuesday showers or rain looks very likely overall of England and Wales as the Low pressure is shown to make landfall over the SE.

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

GEM The theme of GEM this morning shows the easterly flow lasting throughout next week before just weakening a little at the end of the run as the UK then falls under very slack pressure. In the meantime the easterly flow maintains the risk of rain and showers at times across the South, thundery in places while the North sees largely dry and bright weather though even here these areas are not immune to a shower. The end of the run shows fairly benign weather over the UK with fewer showers in general.

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

NAVGEM NAVGEM too shows a sustained period of east or NE winds between High pressure to the North of the UK and Low pressure to the South and SE with thundery showers at times especially over the South while the best weather remains likely in the far NW.

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

ECM ECM today is maintaining the pattern of High pressure to the North and Low pressure to the South through much of next week with thundery rain or showers at times in the South and East while the best weather remains to the NW. Then towards the end of the run this morning High pressure to the North slips SE to the East of the UK with Low pressure then lying across the Atlantic veering winds to a warm SE flow with the risk of showers restricted then to the far West and SW.

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

ECM 10 DAY MEAN (12z) The 10 Day mean Chart from last night continues to show a lot of slack pressure over and around the British Isles with the risk of showers remaining in light winds and reasonable temperatures overall.

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

NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS There remains no strong desire for the models as a whole to remove Northern blocking High pressure over the next few weeks at least with just a shuffling around of pressure systems in an overall benign an quiet weather pattern.

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECM show at 24 hours ECM ahead at 99.5 pts with UKMO at 99.3 pts and GFS at 99.2 pts.  At 3 days ECM is leading with 97.2 pts to UKMO's 95.9 pts while GFS lags behind at 95.6 pts. At 5 days ECM leads with 88.6 pts to UKMO at 86.3 pts and GFS at 84.7 pts. Then at 8 Days ECM has the leading spot from GFS with 57.3 pts to 51.4 pts. Finally at Day 10 ECM has the lead from GFS with a score of 35.6 pts to 34.0 pts.

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day1_PMSL_MSL_G2NHX.png

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.png

MY THOUGHTS  Changes from the models again today remain quite small and focused at the least reliable end of the output runs. In the meantime a continuation of quite benign weather patterns remain although a quite nasty area of Low pressure close to SE Britain early next week could result in some very wet weather for a time. Outside of that the weather will often be bright and warm with some thundery showers at times across the South. Throughout much of the period the best weather will often be over the far NW of Britain while some cool sea mist and haar may affect the East coasts at times but on balance the weather will feel quite warm and humid. Then looking for signs of change longer term there is still some hints of a shift towards lower pressure moving further North over the Atlantic with pressure rising towards the East and maybe SE late in the period. Should that occur a slow shift of emphasis of any showers will move towards the far West while the East and SE see the driest, warmest and brightest weather by then. However, all this is embryonic at the moment as well as being well outside the reliable time frames so let's see how things develop i the coming days to see if there is a growing trend for change as we move deeper into June. I won't be near a PC over the long weekend so there will be no report from me now until Tuesday so enjoy the warmth over the weekend and let's hope that inclement Low to the SE doesn't spoil the party for many on Bank Holiday Monday.

Next Update Tuesday May 31st 2016 from 09:00 

[carinthian]

 

 

6 minutes ago, johnholmes said:

The NOAA and EC-GFS anomaly charts looking pretty similar to one another suggesting mostly settled dry weather for the UK in the 6-10 day period and probably extending beyond 10 days looking at the NOAA 8-14, perhaps a tendency to break down to a more unsettled flow from the SW by day 14, see below

http://www.cpc.noaa.gov/products/predictions/814day/500mb.php

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

The fine details of course will come from the synoptic model outputs with the usual possible changes at even short time scales, much as we are seeing as to how they are dealing with BH Monday details. But with an upper ridge dominant the vagaries of surface features may be less than usual until the break down. Just where the surface flow sits will decide if the east coast of the UK joins in with the rest of the country!

Hope

[carinthian]

Hope you are right JH with regards to 6-10 days forecast. I have never trusted NEly flows at this time of year. Since I have been in Skipton for 2 weeks,felt  the chill. Played many a game of cricket on the high wolds in mid -summer with 3 sweaters on ! Even BH Monday has great uncertainty at the moment. Could be freezing cold and wet or pleasantly sunny. Furthest west looks best. Skipton sort of  in between, hopefully will see the sun again shortly.

[Summer Sun]

At t120 its ECM which is slower in clearing the low this morning when compared with UKMO

[johnholmes]

1 hour ago, carinthian said:

Hope you are right JH with regards to 6-10 days forecast. I have never trusted NEly flows at this time of year. Since I have been in Skipton for 2 weeks,felt  the chill. Played many a game of cricket on the high wolds in mid -summer with 3 sweaters on ! Even BH Monday has great uncertainty at the moment. Could be freezing cold and wet or pleasantly sunny. Furthest west looks best. Skipton sort of  in between, hopefully will see the sun again shortly.

You will have noticed I did not suggest a NE'ly flow as I have no idea just where the surface ridge will sit during the 6-10 day period. It could give a NE'ly flow, or E'ly or SE'ly, who knows yet-the answer is no one with any degree of certainty. Like you fingers crossed that it settles, with a very light flow and a favourable one here (being a touch selfish).

[Summer Sun]

UKMO again shows the low getting pushed away next week as high pressure from the north starts to build still the chance of some showers in the south along the east coast it will be fresher with the risk of some cloud and or fog further west will see the best temps but pleasant enough anywhere in sunshine and shelter

 

The beebs forecast from the other night showing the low moving right over the UK is starting to look unlikely now

Edited May 27, 2016 by Summer Sun

[knocker]

Still looking good in the 7-12 day period with HP in ascendance and temps above average

[Matthew.]

Going by the models the 1/13 week of Summer is looking dry, sunny and warm(even warmer than the 1/13 Summer of 76). Long may it continue!

Edited May 27, 2016 by Matthew Wilson

[Fourty Point Three Degrees]

9 minutes ago, Matthew Wilson said:

Going by the models the 1/13 week of Summer is looking dry, sunny and warm(even warmer than the 1/13 Summer of 76). Long may it continue!

Not by Alex Deakins week ahead forecast over on bbc as HP is always trying to wedge its way in from the North bringing Easterlies in the first week so nothing notably warm and with LP close by theres still a threat of a gloom fest!  

[Matthew.]

5 minutes ago, 40*C said:

Not by Alex Deakins week ahead forecast over on bbc as HP is always trying to wedge its way in from the North bringing Easterlies in the first week so nothing notably warm and with LP close by theres still a threat of a gloom fest!  

Strange enough on the bbc website things look on the whole very good with temps 1c above average or so. Easterlies at this time of year wont be bad if the isobars open up.

[Scorcher]

18 minutes ago, 40*C said:

Not by Alex Deakins week ahead forecast over on bbc as HP is always trying to wedge its way in from the North bringing Easterlies in the first week so nothing notably warm and with LP close by theres still a threat of a gloom fest!  

Is it me or are there more overly pessimistic people in this thread than ever before? An easterly is not a bad direction at all in Manchester, and the source of air is warm. And no, nothing notably warm at first but above average for many, certainly. I'd be slightly concerned if I lived on the East coast but at least the North Sea is starting to warm now so many places might still do better than expected.

[March]

Looking at the next 10 days, it looks average to above average. Not sure what Alex is smoking. 

[East_England_Stormchaser91]

ECM at the end has produced some eye candy for storm lovers! 

[knocker]

Not complete agreement on the position of the upper high between the NOAA and ecm anomalies thus same applies to the orientation of the surface high. Suffice it to say looks a pleasant few days with temps above average. Of course the finer evolution is in the detail.

In the 10-15 period not too bad agreement with the proviso the towards the end of the period with the ecm the Atlantic trough becomes more influential as the HP dissipates.