Model Output Discussion - 3rd May Onwards 00z--->

[Summer Sun]

WSI euro weather: 11 to 15 days means from GFS and ECM keep temperatures below average (Moderate to high confidence), confidence for GFS Op is low

 

 

charts wsi euro weather

[knocker]

Funny I was just going to post this so will just carry on. The GEFS ens at 06z has temps below average for the whole run, sometimes a fair bit. Not confined just to the UK but you are okay if you are popping down to the Peloponnese.

Chart weatherbell

 

[049balt]

Lots of dry weather as we enter the last quarter of the month.

 

http://wxmaps.org/pix/prec4.html

[Summer Sun]

Lots of dry weather as we enter the last quarter of the month.

 

http://wxmaps.org/pix/prec4.html

 

Still looks fairly wet to me especially in some northern and eastern parts of the UK, you'd need the really light blues, Grey or white colours on the map for really dry weather. Have a look at Portugal and most of Spain for the next 7 days

[049balt]

Still looks fairly wet to me especially in some northern and eastern parts of the UK, you'd need the really light blues, Grey or white colours on the map for really dry weather. Have a look at Portugal and most of Spain for the next 7 days

I think it has updated, blue is pretty dry and also temps. looking much better for final week. It is the trend that is important. I live in Ireland and West is best, for the moment anyway, also it is consistent with Met office forecast.

Edited May 13, 2015 by 049balt

[ANYWEATHER]

Evening folks. The changeable to unsettled scenario continues up to T+240 and gone is the high pressure predicted in day ten, which is usually the case....       A rather chilly outlook as low pressure drags colder air across the nation from higher latitudes. As always, the North will bear the brunt, but winds in from a North Westerly at this time of year will always drag cloud and some showery rain across our country, although some sheltered spots will fair better in the strong sunshine. This is what the gfs and ecm show at the moment, but the two models holding hands wont last forever....  Ps .....some serious convective weather from these charts

Edited May 13, 2015 by ANYWEATHER

[Summer Sun]

Whilst no where will be warm next week the south could well avoid the worst of the rain with pressure here slightly higher no where is immune from some showers but the bulk of them look most likely for the north where your closer to the low pressure systems

 

Edited May 13, 2015 by Summer Sun

[knocker]

Tonight's anomalies although ending up with the same result by the 23rd take do not agree on the route as yet. The final result is HP mid Atlantic and trough north over the UK bringing cool unsettled weather.

 

The GEFS has arrived at this by Wednesday but the ECM has a low between Greenland and Iceland which results in a westerly airflow. so the evolution for next week still to be resolved although it looks a fair bet  it won't differ that much from that which is currently on offer by the 23rd.

Charts weatherbell

 

[knocker]

A quick look at the GFS run this morning out to the 22nd

 

The weekend has unstable westerlies for the north with the south under the influence of the ridge. This soon gives way as the next low approaches from the NW that duly arrives on Tuesday. This soon moves away but is quite quickly replaced by another depression that travels SE from north of Iceland and dominates the rest of the run ending up in the North Sea and dragging in some cool air from the NW.

[Polar Maritime]

The GFS continues to show a cool unsettled Pm flow next week, Turning Northerly for weeks end.

 

[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 THURSDAY MAY 14TH 2015.

 

THE CURRENT GENERAL SITUATION A depression will move ESE across Southern England and the English Channel through today with a ridge of High pressure following tonight. 

 

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

 

MODELS-2 WEEK HEADLINE Changeable with some showers at times especially over the North and East but spells of dry and fine weather too for all. Generally rather cool, especially by night.

 

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream axis will move gently North tomorrow and over the weekend to be travelling East across Northern Scotland. Then it eases back South as a UK trough is formed and realigns a long way South at the base of a trough late next week before breaking up and gradually returning North up the Western side of the UK two weeks from now.

 

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

 

GFS OPERATIONAL The GFS Operational this morning shows High pressure to the SW over the weekend gradually losing control of the UK weather as Low pressure to the North of the UK slips South across and just to the East of Britain. Showers and outbreaks of rain in cool weather seems likely for all areas for a large porton of the run before Low pressure develops strongly over the Atlantic reversing winds to a more Southerly wind and milder weather spreads North and East across the UK with rain restricted to the North and West.

 

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

 

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

 

THE GFS CONTROL The GFS Control run this morning follows a very similar path through the first 10 days of the run before High pressure is shown to build across the UK in 14 days time with fine and dry weather for all by then.

 

THE GFS CLUSTERS The GFS Clusters are very High pressure based this morning with High pressure shown by many members to lie across or just to the West or NW of the UK with fine weather as a result. Just 20% of members indicate an Atlantic influence affecting the North and West of Britain in 14 days.

 

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 cool and showery trough moving South over the UK early next week with High pressure lying close to the West of the UK by next Wednesday with fine and bright if never overly warm weather to all areas by then with the best weather in the SW.

 

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

 

THE FAX CHARTS The Fax Charts follow the theme of the raw data charts in as much as High pressure to the SW keeps the weather largely fine if rather cloudy at times over the weekend across the South whereas the North sees occasional rin from Atlantic troughs. These slip South across the UK at the beginning of next week.

 

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

 

GEM GEM this morning shows a similar drift into cool and showery territory next week as Low pressure slips SE across all areas in the shape of a trough and then quickly followed by another one to maintain the cool and showery theme well out towards the end of the month when rather better conditions look like developing then.

 

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

 

NAVGEM NAVGEM makes rather less of the longevity of the trough next week as High pressure moves in off the Atlantic later next week. So after several cool days with showers dry and warmer weather with some sunshine could be affecting all areas though with chilly nights late next week.

 

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

 

ECM ECM indicates a largely cool and showery theme as we move through next week and the start of the Bank Holiday weekend as Low pressure areas slip SE across or to the NE of the UK with cool and showery NW winds affecting all areas with the least showers towards the SW but temperatures never very inspiring anywhere especially at night when touches of frost remain a possibility.

 

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

 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart  from last night shows High pressure to the SW of the UK still badly positioned for the UK while Low pressure remains locked to the North and NE of Britain with cool air enveloping the UK in NW or West winds and showers.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trends mostly remain in agreement although with a few exceptions on cool NW winds and occasional showers across the UK for the extended outlook period this morning.

 

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 96.8 pts followed by UKM at 96.1 pts and GFS at 95.3. At 5 days ECM  leads UKMO with 86.0 over UKMO's 84.3 pts with GFS at 82.4. At 8 days ECM remains the leader with 53.4 pts over GFS's 52.5 pts. Then at Day 10 GFS gains superiority at 34.9 pts over ECM at 34.8. 

 

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 change in the overall theme of the output this morning. The story remains one of a North/South split in conditions at the weekend with the North seeing occasional rain in a Westerly breeze while Southern areas stay largely dry and bright. Then as we move into next week pressure falls for all as cool Low pressure slips South and SE over and to the NE of the UK with increasingly showery and cool conditions as winds veer NW. This pattern then appears to become locked in from much of the output with reinforcements to the pattern arriving from the North in time for the Bank Holiday Weekend. However, there are a few exceptions to this and the GFS Ensembles seem to like the idea of High pressure being close by to the UK in two weeks but whether that would be too late for the Holiday break is open to doubt. Navgem too builds High pressure in quickly later next week with brighter and warmer weather shown as a result. So a few different evolutions shown but all point towards rather chilly conditions in winds from a point between West and North for much of the time dragging cool winds down from the North so temperatures look like never being partiularly high in the near future. However, no large amounts of rain look likely and many parts of the South and West could see a lot of dry and bright weather with the most showers over the North and East in the afternoons. However, those same clearer skies to the South and West leave the door ajar in the risk of some areas receiving unwelcome ground frost at night. 

 

Next update from 08:00 Friday May 15th 2015

Edited May 14, 2015 by Gibby

[ANYWEATHER]

This is why we have to be careful when looking at the models and seeing something at T+168 and jumping on the band wagon and thinking high or low pressure is certain. Unfortunately for instance the ecm and the gfs is showing low pressure dominant up to T+240 ,in the day ten period, so disappointingly cool and rather unsettled for all. The charts below for instance show how much the ecm has changed its output in the last few days....

Edited May 14, 2015 by ANYWEATHER

[knocker]

Gibby

 

First I would like to say I think you do an admiral job with your daily analysis. It takes time and a fair bit of effort but I must admit I don't follow the bit highlighted in your GFS ops analysis.

 

 

GFS OPERATIONAL The GFS Operational this morning shows High pressure to the SW over the weekend gradually losing control of the UK weather as Low pressure to the North of the UK slips South across and just to the East of Britain. Showers and outbreaks of rain in cool weather seems likely for all areas for a large porton of the run before Low pressure develops strongly over the Atlantic reversing winds to a more Southerly wind and milder weather spreads North and East across the UK with rain restricted to the North and West.

 

 

It would be more precise to say the low develops NNW of the UK travels SE into the North Sea bringing bands of rain from the NW. This brings westerlies for a short while before the cooler NW pattern sets in. I'm afraid I don't follow the milder weather spreading north.

 

Anyway no big deal as the detail will be all change tomorrow.

 

[Summer Sun]

Gibby

 

First I would like to say I think you do an admiral job with your daily analysis. It takes time and a fair bit of effort but I must admit I don't follow the bit highlighted in your GFS ops analysis.

 

 

It would be more precise to say the low develops NNW of the UK travels SE into the North Sea bringing bands of rain from the NW. This brings westerlies for a short while before the cooler NW pattern sets in. I'm afraid I don't follow the milder weather spreading north.

 

Anyway no big deal as the detail will be all change tomorrow.

 

Having looked through the latter stages of GFS I can see why Gibby has posted this

 

[BlueHedgehog074]

For anyone getting a bit confused, this was probably the Low Pressure system Gibby was referring to towards the end of the GFS 0Z run (the one in the Atlantic drawing in the Southerly feed).

(Edit: Summer Sun's beaten me to it).

Will just add that the GFS/ECMWF and NOAA (6 to 10 day versions) anomaly charts continue to show a cool and unsettled picture for the UK with troughing over us (although with the lowest heights likely to be concentrated to our North or North-East). The worst of the disturbed weather conditions also would seem to be concentrated over Northern areas. Though I think as one or two people mentioned yesterday, despite the cool Westerly or North-Westerly flow it shows at the 500mb level, could still feel fairly warm/mild in sunny spells between the showery weather, most especially towards the South. Some kind of Atlantic ridging is evident too, which could help drop Lows down over us, or to our East, from the North-West.

Edited May 14, 2015 by DiagonalRedLine

[knocker]

Okay I apologise and withdraw my comment as I didn't appreciate he meant out to the end of the extended period.

[summer blizzard]

Operational Euro is almost bang in line with it's day 10 ensemble mean. With the anomaly chart not really changing the US pattern, i simply don't see more than a day or two of warmth from a transient ridge.

 

[Pennine Ten Foot Drifts]

I think regardless of the nuances of the different models, barring a fairly dramatic 'volte face' there is fairly strong and consistent model agreement that there is no solid settled spell, (and certainly no sustained summer heat), on the horizon, and that what we have in store is generally unsettled, general breezy, and predominantly at or below average temperatures, and any pleasant interludes will be just that, transient and scatterred. In other words, proper summer, (at least in terms of what most people would expect 'proper summer' to look like), doesn't look like it's going to arrive this May.

[Cheshire Freeze]

Operational Euro is almost bang in line with it's day 10 ensemble mean. With the anomaly chart not really changing the US pattern, i simply don't see more than a day or two of warmth from a transient ridge.

 

 

Some of the charts on offer are very reminiscent of June 2008 actually. In fact you could pretty much pluck any summer month in that run of summers where N blocking featured in one way or another such as what is projected. Hopefully we'll get a shot at some lovely Pm convective spells such as what is predicted for next Tues at present; slack LP and strong solar heating is ideal...I see the most storm activity from such set ups.

Edited May 14, 2015 by CreweCold

[Frank Trough]

Some of the charts on offer are very reminiscent of June 2008 actually. In fact you could pretty much pluck any summer month in that run of summers where N blocking featured in one way or another such as what is projected. Hopefully we'll get a shot at some lovely Pm convective spells such as what is predicted for next Tues at present; slack LP and strong solar heating is ideal...I see the most storm activity from such set ups.

 

they also have a passing resemblance to a number of spells in recent Mays (excluding last year). It's a month that really does have low expectations for me now.

 

[Milhouse]

May 2010 springs to mind as a month that started on a very cool and disappointing note but turned much drier and warmer for the last week of the month.The latest GEFS ensembles do look more promising for the end of the month so there is some hope. As for the next 10 days the warmest conditions will probably come later on next week as winds turn more westerly. The one saving grace is that the models arent showing a northerly/northeasterly bringing muck off the North Sea, but otherwise its a very uninspiring outlook. At least its not summer proper.

 

The temperatures below look pleasant enough i suppose in light winds.

 

[Gibby]

Gibby

 

First I would like to say I think you do an admiral job with your daily analysis. It takes time and a fair bit of effort but I must admit I don't follow the bit highlighted in your GFS ops analysis.

 

 

It would be more precise to say the low develops NNW of the UK travels SE into the North Sea bringing bands of rain from the NW. This brings westerlies for a short while before the cooler NW pattern sets in. I'm afraid I don't follow the milder weather spreading north.

 

Anyway no big deal as the detail will be all change tomorrow.

 

My fellow posters on here have already answered I know but to confirm from the horses mouth so to speak it was what the end of the GFS 00z run was showing that I was referring to and indeed showed a warm up with a switch of wind to the South or SW. On the other comment about the Low pressure moving South down over the UK  I was referring to a Low pressure trough attached to Low pressure moving SE down the North Sea. In the haste to get the info out to you folks I may have badly worded it but I still believe the general thrust of coolness from the North was clear enough to the less knowledgeable folks than us who don't necessarily care whether the coolness comes from the North or NW. Anyway all that aside thank you for your kind comments about my daily report and as long as people like reading them I will continue to compile them.

Edited May 14, 2015 by Gibby

[Frank Trough]

May 2010 springs to mind as a month that started on a very cool and disappointing note but turned much drier and warmer for the last week of the month.The latest GEFS ensembles do look more promising for the end of the month so there is some hope. As for the next 10 days the warmest conditions will probably come later on next week as winds turn more westerly. The one saving grace is that the models arent showing a northerly/northeasterly bringing muck off the North Sea, but otherwise its a very uninspiring outlook. At least its not summer proper.

 

The temperatures below look pleasant enough i suppose in light winds.

 

 

There are some similarities between the forecast charts for early next week and, dare I say it, 2012...please don't be an omen...

 

[Gael_Force]

There's more than a passing resemblance to 2003 too and as I've just posted on the ENSO thread, a PDO very similar in temp profile.

 

http://www.meteociel.fr/modeles/archives/archives.php?day=12&month=5&hour=0&year=2003&map=0&mode=2

 

We can see anything we want as far as similarity but there will always be the little nuances that make each month/season unique.

[Captain Shortwave]

It is all really dependent on how long that Atlantic ridge persists. If it does then it will be cool and unsettled for the UK as low pressure slips over the country from the north west.

From there we could see the ridge collapse offering a return to a normal westerly patter or the ridge could build into the UK giving settled weather. Or we could sheer the ridge and build heights towards Greenland. If the latter happens then again you could end up with a mobile and southerly tracking jet or you could stall low pressure in the mid Atlantic resulting in heights building across most of Europe.

 

Plenty of options available, it is just about when it will happen and to be honest there doesn't appear to be much sign of a change in sight, though a few operationals have sheered the ridge like the ECM at day 10.