Model Output Discussions 18z 31/01/2016

[nick sussex]

That stupid shortwave near Iceland needs to do one and bog off! That's a real pain as its just waiting to phase with the upstream troughing.

[feb1991blizzard]

Just now, nick sussex said:

That stupid shortwave near Iceland needs to do one and bog off! That's a real pain as its just waiting to phase with the upstream troughing.

Yes it looks like I may have spoken too soon and it may bugger us.

[nick sussex]

Just now, feb1991blizzard said:

Yes it looks like I may have spoken too soon and it may bugger us.

These Icelandic shortwaves would survive a meteor hitting the earth! You just know that regardless of any other changes that shortwave will survive intact in future runs. We might get away with it if the upstream pattern remains amplified.

[feb1991blizzard]

4 minutes ago, nick sussex said:

These Icelandic shortwaves would survive a meteor hitting the earth! You just know that regardless of any other changes that shortwave will survive intact in future runs. We might get away with it if the upstream pattern remains amplified.

Sorry Nick, I was way behind you, I was watching it on Netweather as meteociel not doing wonders for my computer speed lately so you were probably wondering what I was on about when I called a good run - just seen it on meteociel now.

Edited February 16, 2016 by feb1991blizzard

[nick sussex]

3 minutes ago, feb1991blizzard said:

Sorry Nick, I was way behind you, I was watching it on Netweather as meteociel not doing wonders for my computer speed lately so you were probably wondering what I was on about - just seen it on meteociel now.

No you were right it did try and bugger us! lol But the pattern remained amplified upstream although I'm sure the GFS will try and find something else to annoy me with! It didn't take long now that Siberian high wants to keep the pattern too far west!

Edited February 16, 2016 by nick sussex

[Banbury]

An interesting start to March still on offer from GFS

[Singularity]

Darn it GFS, I wanted the Scandi trough further south next week, not the small low sneaking across under the mid-Atlantic ridge! 

As for the longer term...

 

A faster transition to a -ve AO compared to the 12z, but the addition of a bombing low over Canada is not helpful. Good test though to see if the blocking signal indicates something robust enough to withstand such an onslaught and produce blocking NE of the UK perhaps.

 

Edit: oh I see from Banbury's post that it loses the battle but then comes back with a vengeance to win the war! Netweather's lagging behind a bit tonight.

That's impressively consistent with the 12z, and in fact so long as the model keeps producing a favourably aligned strat. split and MJO movement to phase 8, this theme may prove to be commonplace in the model's output for the end of Feb/early March.

Then, of course, the complications will be latched onto 

 

Edited February 16, 2016 by Singularity

[bryan629]

4 minutes ago, Banbury said:

An interesting start to March still on offer from GFS

two runs in deep deep FI , with similar endings.... 

The PV gets knocked out of the ring as well ..... 

 

[swilliam]

Heavens above  - we can get cold weather with a tanking -ve AO

If we do not get something interesting in a couple of weeks I will be amazed  - unfortunately probably not as extreme as this (this is for the benefit of NS who wanted to see some N blocking)

[Mildcarlisle]

And where did all this hype come from regarding snowfall from this front moving southeast? It may still happen that snowfall occurs but taking a look at this 'now' chart,head scratching can commence forthwith likes...

Edited February 17, 2016 by Mildcarlisle

[swilliam]

6 minutes ago, Mildcarlisle said:

And where did all this hype come from regarding snowfall from this front moving southeast? It may still happen that snowfall occurs but taking a look at this 'now' chart,head scratching can commence forthwith likes...

No hype - people discussing what the models were/are showing (including the MetO) which varied from no snow to significant snow from run to run. I would wait until it has happened in any case but whatever happens this is what was shown.

Edited February 17, 2016 by swilliam

[Cheshire Freeze]

Well we may finally get our E'ly....just as March is about to be ushered in

Potential for a big retrogression later on

Yep, HP tries to head out back into the N Atlantic with increased amplification

Plenty of signals for March but none of them particularly warm it has to be said!

On a side note, Monday could be fun.....hail, sleet and snow showers blown through on a strong NW wind....UKMO keeps the flow going from Sunday night right through to Monday night

GFS slightly quicker to blow it through

Still, perhaps some temporary local accumulations to lower levels where banding occurs

Edited February 17, 2016 by CreweCold

[snowblizzard]

7 hours ago, Mildcarlisle said:

And where did all this hype come from regarding snowfall from this front moving southeast? It may still happen that snowfall occurs but taking a look at this 'now' chart,head scratching can commence forthwith likes...

Cold air under cutting from NW - back edge sleet or snow!

But mainly only above 200 metres with those temperatures.

Absolutely nothing to get hyped about!

Edited February 17, 2016 by snowblizzard

[winterof79]

3 hours ago, CreweCold said:

Well we may finally get our E'ly....just as March is about to be ushered in

Potential for a big retrogression later on

Yep, HP tries to head out back into the N Atlantic with increased amplification

Plenty of signals for March but none of them particularly warm it has to be said!

On a side note, Monday could be fun.....hail, sleet and snow showers blown through on a strong NW wind....UKMO keeps the flow going from Sunday night right through to Monday night

GFS slightly quicker to blow it through

Still, perhaps some temporary local accumulations to lower levels where banding occurs

The way things are panning out in the model out put this season there are two hopes of the Easterly. Bob hope and ....ing no hope. Ensembles look nothing special either

Edited February 17, 2016 by winterof79

[Nick F]

Some notable medium-range differences between 00z GFS and EC operationals this morning,.

GFS keen on trough disruption again as a lobe of the trop Polar Vortex breaks away SE into Western Europe from t+216 eventually forming an upper low over the western Med while an easterly develops to the north over the UK (albeit not deep cold advection).

ECM, on the other hand, extends a lobe of the PV SE toward the UK, but has no trough disruption and keeps the UK under a cyclonic SWly flow.

The differences may stem to differing pattern upstream, EC develops a cut off upper low over SE USA which pulls the Azores high west into NE USA / Ern Canada keeping the upper flow flat over the Atlantic. While GFS keeps a high amplitude trough over eastern N America and thus more amplification downstream over the N Atlantic - which is more conducive for trough disruption over Western Europe.

so worth keeping any eye on those NOAA updates today ...

Edited February 17, 2016 by Nick F

[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 WEDNESDAY FEB 17TH 2016

THE CURRENT GENERAL SITUATION   A frontal trough will continue to move slowly and erratically East across the UK today and tonight followed by a ridge of High pressure moving East across the UK tomorrow.

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

 CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across the South of the UK lies around 5000ft or so across the South and nearer 2000ft over Scotland. Through the day and tonight the freezing level will fall over England and Wales to around 2000ft so that the level is broadly the same everywhere with snow showers across the hills and mountains of the North. Some sleet or snow may turn up on higher ground of England and Wales above 1000ft later today and tonight especially towards the Midlands and the SE. 

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 rain or showers at times with snow over hills. Temperatures mostly near or somewhat below average though with a few short milder interludes in the South.

THE GFS JET STREAM FORECAST  The Jet Stream will strengthen across the Atlantic Ocean over the coming days surging across the UK through the weekend and next week. Then the flow becomes more sine wave with a period of deep troughing across the UK late next week and a more diffuse pattern developing thereafter.

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

GFS OPERATIONAL The GFS Operational Run today shows a generally rather chilly and changeable pattern across the UK through the next few weeks. In Summary the run shows a lot of Atlantic based weather with spells of rain followed by spells of showers and colder conditions with snow in places and not necessarily just on Northern hills at times. A period of more generally cold weather as Low pressure slips South across the UK late next week is shown lasting several days as High pressure builds behind with sharp night frosts. Then towards the end of the period more rather cold Low pressure is shown to slip down over the UK from the NW with further rain or perhaps snow at times.

GFS CONTROL RUN The theme of the Control Run also shows a strong Atlantic influence to the weather pattern across the UK through the next few weeks. The alternating pattern of milder vs colder is also shown on this run although there seems a milder phase through the start of the second week as High pressure to the South pushes the Jet Stream North for a time and allows tropical maritime air into the mix in the South at least before it looks more changeable and rather cold again across many areas by the end of the run.

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

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

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 GFS Clusters today still show a lot of support for a NW flow to lie across the UK in two weeks time. As of previous days the differences between members remain focused on what extent this NW flow has both on temperatures and unsettledness of the weather likely across the UK with High pressure either focused near the Azores or displaced further North in the Atlantic.

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 a strong Westerly flow with heavy rain on Saturday swept away East on Sunday as a cold front sweeps through from the WNW. Then the early days of next week look cold and windy with wintry showers and frosts at night especially across the North and West. A ridge of High pressure is then shown to approach the UK from the Atlantic by midweek.

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

THE FAX CHARTS The Fax Charts today support the raw data reasonably accurately as it shows the slack pressure of the next few days reinvigorating to a strong Westerly flow by the weekend with fronts straddling England and Wales by then with heavy rain at times but milder too. Then a cold front is shown to sweep SE on Sunday with colder showery air reaching all areas with some wintry showers across the North and West.

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

GEM GEM today shows a complex Atlantic weather based pattern over the 10 day period with winds basically Westerly throughout with rain or showers at times. With much cold air to the North of the UK  there is every chance indicated in the model that the air over the UK could be often cold enough for snow on hills especially as usual over Northern Britain and more generally late in the period.

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

NAVGEM NAVGEM painta a changeable picture this morning and has small differences to the majority of the other models in as much as it shows milder conditions across the South lasting rather longer over the weekend still with rain at times though. Then next week the pattern remains changeable with colder air sweeping SE with some wintry showers in places giving way to drier weather with some night frosts by this time next week.

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

ECM ECM this morning looks very changeable over the next 10 days with the current wet weather slipping away east tomorrow ahead of strengthening and milder westerly winds with rain at the weekend. Deep Low pressure to the NE early next week pulls strong cold NW winds with sleet or snow showers in places lasting until midweek when a frosty ridge passes across from the West. Then hot on it's heels the end of next week turns wet and windy again for many in closer to average temperatures again at least for a time.

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

ECM 10 DAY MEAN The 10 day mean chart today shows the Jet stream a long way South in 10 days with Low pressure close to northern Scotland and High pressure well away to the SW. The UK looks likely to lie in a NW flow with rain or showers at times in temperatures near to or a little below average with snow a risk on hills of the North at least at times.

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

NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The overall theme remains for a Westerly Atlantic based pattern in fluctuating temperatures and rain and showers at times.

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECM show at 24 hours ECM ahead at 99.6 pts with UKMO at 99.5 pts and GFS at 99.4 pts.  At 3 days ECM is leading with 97.7 pts to UKMO's 97.2 pts while GFS lags behind at 96.7 pts. At 5 days ECM leads with 91.9 pts to UKMO at 89.9 pts and GFS at 89.0 pts. Then at 8 Days ECM has the leading spot from GFS with 69.6 pts to 65.5 pts. Finally at Day 10 GFS leads today at 51.8 pts to ECM's 51.2 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   High pressure remains elusive in the model outputs this morning and leaving temperatures aside it looks likely than the official Winter end of 2015-2016 will finish as it began with Atlantic based Westerly winds and rain at times the likely pattern as we enter the meteorological Spring. However, having said that the source of air for much of the period will ensure it is unlikely to be as mild as back in December as Low pressure areas to the North hone it much closer to the UK than then with rain, heavy at times for all areas followed by colder shower spells. With the Jet Stream still quite strong and a long way South at times it will feel rather cold for periods through the next few weeks and although widespread long lasting cold remains unlikely some short cold snaps between weather systems could provide enough excitement at times to provide some heavy showers with snow in places and possibly hail and thunder too especially in the North. Not much else to say really this morning with the main differences between the models focusing on timing and orientation of various weather systems as they cross the UK leading to day to day differences in the weather experienced at the surface within the general framework of the Atlantic based Westerly pattern.        

Next Update Thursday February 18th 2016 from 09:00

[peborant]

I am sorry but I do not agree with the fact that freezing level is at 2000ft at the minute as I have 2 inches of fresh snow lying IMBY at 45m asl however many ft that is (150ft??). Temps hovering around 0C since 3am. 

Model-wise it does look like we are headed to a colder period with short mild shots interspersed. As someone said a while ago, seasons appear to be two months behind schedule indeed. 

Edited February 17, 2016 by peborant

[johnholmes]

There are differences between the 3 anomaly charts I use, as Nick posts above differences between them but essentially, in the UK area, they show a flow north of west around the Atlantic ridge into the trough over Europe. The NOAA version last evening did not show this, see below, so with differences in the 3 then more caution than usual is required for the 6-10 day outlook.

 http://www.cpc.noaa.gov/products/predictions/610day/fxus06.html

[Nick F]

An interesting outlook from the extended 00z EPS mean as we head into the first few days of March.  By day 15, it shows a -ve height anomaly centred over the North Sea and over eastern USA, while +ve height anomalies dominate the arctic circle including Greenland and Svalbard. The 00z EPS control at day 15, though not to be trusted at that range shows ridging extending north from the Atlantic across Iceland and up to Svalbard and an upper trough centred over northern Italy. Cold start to March?

[NorthYorksWeather]

1 hour ago, Nick F said:

An interesting outlook from the extended 00z EPS mean as we head into the first few days of March.  By day 15, it shows a -ve height anomaly centred over the North Sea and over eastern USA, while +ve height anomalies dominate the arctic circle including Greenland and Svalbard. The 00z EPS control at day 15, though not to be trusted at that range shows ridging extending north from the Atlantic across Iceland and up to Svalbard and an upper trough centred over northern Italy. Cold start to March?

Cheers for that Nick. Certainly would tie in with some of the eye candy that the GFS was churning out in F.I, big question is can the signal be maintained and come to fruition? 

[Singularity]

I think it says a lot that the ECM 00z was such a dong when it came to next week and phasing those lows, yet still produced the dramatic dive south in the jet through Europe for days 9-10 with height rises to the north. 

Really there is impressive synergy between the longer range suggestions of ECM and GFS at the moment, ensembles included. With strong MJO forcing comes this potential for a more confident outlook - but as ever this season, the stratosphere raises some questions. A significant warming event, quite probably a SSW, is being indicated end of Feb/start of March, but exact timing is uncertain, and location even more so, with the vortex movement and extent of weakening changing significantly from run to run.

Put it this way though - the scope of potential ranges from an irritatingly chilly March with some cold rain for the south in particular to something on a par with March 2013 (yes, I know, that seems crazy - just three years after the coldest in about a century!), so there is a lot to play for here... but losing could be particularly unpleasant unless we happen to see a blocking high locate in just the right place for an early spring instead.

[Cloud 10]

Extreme caution advised,but the CFS has been churning out a lot of northern blocking in March charts over the last few weeks,the latest run was rather spectacular for example.

 

[bobbydog]

currently a strong signal for snow virtually everywhere on sunday. (much stronger than todays feeble effort anyway) just 4 days away-

[Blake]

Models still unsure about when precipitation will clear the SE just 24 hours out. One has it lingering until the evening...one has it clear early afternoon. 

 

[Ripeberry]

3 minutes ago, bobbydog said:

currently a strong signal for snow virtually everywhere on sunday. (much stronger than todays feeble effort anyway) just 4 days away-

Isn't it supposed to be very mild on Sunday?  If it can't manage to snow today, there's not a snowball in Hell's chance that it will snow at the weekend, lol!