Model output discussion - 21st Jan Onwards

[TomDav]

10mb Zonal winds dropping to 12.1 m/s on the 18Z

Also a nice arctic high at the end of the run

[kumquat]

Not such a bad place to be. 1st of February. Displacement of vortex out of its usual home:

18Z GFS

 

ECM at same timeframe singing the same tune (or, at least, trying to get there)

In both scenarios, downforce of cold air from the pole with a cake-slice swathe of high pressure swinging around the globe and pressing, pressing to our locality.

Just about the right timing to force cold air into Europe and then swing it back with reverse zonal flow as heights cut in above.

[blizzard81]

2 minutes ago, kumquat said:

Not such a bad place to be. 1st of February. Displacement of vortex out of its usual home:

18Z GFS

 

ECM at same timeframe singing the same tune (or, at least, trying to get there)

In both scenarios, downforce of cold air from the pole with a cake-slice swathe of high pressure swinging around the globe and pressing, pressing to our locality.

Just about the right timing to force cold air into Europe and then swing it back with reverse zonal flow as heights cut in above.

You make it sound so easy. If only

[Man With Beard]

Heading in the right direction - we now have 2 out of 51 ECM ensembles members bringing snow to London by D13... thats one more than yesterday ...  but oh dear.

http://www.weathercast.co.uk/meteo/eps/ensemble-tt6-london.gif

[wishingforsnow]

4 minutes ago, Man With Beard said:

Heading in the right direction - we now have 2 out of 51 ECM ensembles members bringing snow to London by D13... thats one more than yesterday ...  but oh dear.

http://www.weathercast.co.uk/meteo/eps/ensemble-tt6-london.gif

However the average is trending downwards towards the end of the run...

[kumquat]

3 minutes ago, Man With Beard said:

Heading in the right direction - we now have 2 out of 51 ECM ensembles members bringing snow to London by D13... thats one more than yesterday ...  but oh dear.

http://www.weathercast.co.uk/meteo/eps/ensemble-tt6-london.gif

 

I'm seeing the greatest spread fanning out at T+120 after the crazy snow shenanigans in the USA. That system embeds itself into the vortex and wings its way over here like it has something to say. I'm not so sure that feature is being modelled very well.

[Ali1977]

Well this mornings runs are particularly rubbish for anything cold...I wish I could go forward in time and see if it's actually worth watching the models over the rest of winter waiting for something better... Still, guess that's part of it!!!

[IDO]

The GFS op and control keeping to their guns with HP to the south and LP to the North up till D16:

 mean: 

From the mean there is little sign of any hope of an Atlantic ridge developing quickly from the D16 mean. The ECM has moved towards the GFS this morning with regard to the PV chunk circling to our north at D10 so preventing those pulses of Azores energy pushing north:

ECM D10:   Gem: GFS: 

GEM is not dissimilar but with less grouping of the PV energy. The Alaskan heights  combined with the residue ridge over Russia means that the PV piece on our side of the NH is restricted in its movement and with no sustained HLBs it just gets pushed between Greenland and Scandi, and back again, and that is hopeless for any cold.The next 10 days look poor for cold and I would say confidence from there is higher than normal so little change up till D15, as this holding pattern has us on the wrong upper air cold axis. A sign as we move towards D15 on the GEFS that the Euro heights will push west allowing lower heights over Europe, but with the PV chunk to our NW we need other factors to get cold from that scenario.

From an IMBY perspective a predominantly dry run for the south from D4 to D15 on the GFS op:

RAIN:   Temps: 

So the NW again at risk of the most rain but hopefully not as bad as December. A mild end to Jan looks likely so the CET should be >1c above average (15c possible in the next 72 hours). 

The displacement of the strat PV looks likely in early Feb, with possibly a SSW to follow, so potential for changes to feed in around the D15 mark and I think that is what we now have to look for.

 

 

[Frosty.]

Tomorrow looks very springlike according to the Gfs 00z with 13c 55f widely and in any sunny breaks 15/16c could be yours!

[Frosty.]

The Gfs 00z gradually shows high pressure building in close to the south with the bulk of the unsettled weather targeting the north, it's a generally mild run, indeed there are some very balmy springlike days with temps easily into the mid teens celsius, however, there is more of a polar maritime influence for a time later next week with snow on northern hills and slight frosts making it feel more seasonal and towards the end of the run the charts have a bit more of a wintry flavour, at least in the north but overall it's not what we would expect in the heart of winter, it's laughable really

Edited January 23, 2016 by Frosty.

[bluearmy]

no sign to me that any movement of the trop vortex to scandi will result in its complete departure from eastern canada. a small lobe would be ok but cant see that amount of withdrawal sticking. add to that the euro high anomoly going nowhere for the next fortnight - either the models are all wrong or any proper wintry weather is second half feb onwards at best. i guess the events in the strat may be confusing the picture but we know that a model built to get the strat/trop coupling right (GLOSEA-5) isnt seeing anything before mid feb either.

find a way to remove those euro heights and we would be in a very different place, either via a southerly jet or a ridge to our west.

Edited January 23, 2016 by bluearmy

[fergieweather]

8 minutes ago, bluearmy said:

no sign to me that any movement of the trop vortex to scandi will result in its complete departure from eastern canada. a small lobe would be ok but cant see that amount of withdrawal sticking. add to that the euro high anomoly going nowhere for the next fortnight - either the models are all wrong or any proper wintry weather is second half feb onwards at best. i guess the events in the strat may be confusing the picture but we know that a model built to get the strat/trop coupling right (GLOSEA-5) isnt seeing anything before mid feb either.

Latest (yesterday's) GloSea5 remains consistent and - as I mentioned on Thursday eve - has ECMWF support:

- Broadly westerly pattern to mid-Feb

- Switch to meridional pattern mid-Feb onwards, with ridging in Atlantic; UK flow NW-N'ly

- Thus increased prospect of colder weather relative to 1st half of month

[Frosty.]

2 minutes ago, fergieweather said:

 

- Switch to meridional pattern mid-Feb onwards, with ridging in Atlantic; UK flow NW-N'ly

- Thus increased prospect of colder weather relative to 1st half of month

About flippin time..lol

[West is Best]

36 minutes ago, fergieweather said:

Latest (yesterday's) GloSea5 remains consistent and - as I mentioned on Thursday eve - has ECMWF support:

- Broadly westerly pattern to mid-Feb

- Switch to meridional pattern mid-Feb onwards, with ridging in Atlantic; UK flow NW-N'ly

- Thus increased prospect of colder weather relative to 1st half of month

 

This is the same GloSea5 that completely missed the last and only cold spell of the winter, telling us that the signals were for continuation of rampant Atlantic?

The models are zonal with a whopping great Bartlett high to our south, which is THE dominant signal right now and for the immediately foreseeable future. Unfortunately.

Edited January 23, 2016 by Paul

[cornish snow]

7 minutes ago, fergieweather said:

Latest (yesterday's) GloSea5 remains consistent and - as I mentioned on Thursday eve - has ECMWF support:

- Broadly westerly pattern to mid-Feb

- Switch to meridional pattern mid-Feb onwards, with ridging in Atlantic; UK flow NW-N'ly

- Thus increased prospect of colder weather relative to 1st half of month

 

Toppler?

[snawbaw]

Just checking...do models only show probabilities for weather?  They are not actual forecasts are they?

[Mair Snaw]

15 minutes ago, fergieweather said:

Latest (yesterday's) GloSea5 remains consistent and - as I mentioned on Thursday eve - has ECMWF support:

- Broadly westerly pattern to mid-Feb

- Switch to meridional pattern mid-Feb onwards, with ridging in Atlantic; UK flow NW-N'ly

- Thus increased prospect of colder weather relative to 1st half of month

Thank you again Ian for your valued input.... this sounds like it goes along with what has been said since Autumn that this winter would be a late starter.. and that anything before this would be brief.. i guess many are just getting hung up on seeing a UK wide blizzard, but when does this ever really happen?? that said some very good stuff to view as we go along our way... winter is not all about the snow falling... i do like a good snow fall like many in here but a good storm or 2 is also something to be enjoyed as long as it does not come with the amount of rain we have seen this winter..

Edited January 23, 2016 by bigsnow

[Nouska]

30 minutes ago, West is Best said:

 

This is the same GloSea5 that completely missed the last and only cold spell of the winter, telling us that the signals were for continuation of rampant Atlantic?

The models are zonal with a whopping great Bartlett high to our south, which is THE dominant signal right now and for the immediately foreseeable future. Unfortunately.

Hey, don't shoot the messenger or the model - things in the atmosphere have been pretty extreme for a few weeks. It is not some static entity the models are dealing with and we do not know what the cluster percentages were. Met office can only go with probabilities.

[Ali1977]

30 minutes ago, West is Best said:

 

This is the same GloSea5 that completely missed the last and only cold spell of the winter, telling us that the signals were for continuation of rampant Atlantic?

The models are zonal with a whopping great Bartlett high to our south, which is THE dominant signal right now and for the immediately foreseeable future. Unfortunately.

A bit harsh, Ian is passing on info from one of the best Weather models in the world - obviously it can't see into the future, but apart from the little blip ref cold last week ( which it actually did pick up) it has performed v well lately. 

A pattern change is probably easier to pick up than specific weather events so I for one think the chances of it happening are quite high, especially taking into account what is happening in the NH.

[Dunstable Snow]

The NH view on the ECM at 240 is interesting. Pressure high right across the Artic from Alaska to Siberia and a strong -AO signal. The core of the PV this side of the globe still to the North West of the British Isles leaving us in a Westerly/South westerly flow and pressure high to the south. Can things progress positively from here with the core of the PV relocating to Scandi and western Siberia and low heights draining away from Greenland and NE Canada? This would appear to be the route map outlined by many of the experts including IF and the meto. How long will it take and how far north will the ridging get ? A mid Atlantic ridge that doesnt ridge strongly up into or link with high pressure in the Artic is about as exciting as Sunday tea at my nan's for those of us south of the north midlands (particularly when we get beyond mid winter)  I think we all deserve significantly  better than that given what we have had to suffer over the last three years.

Enjoy your weekend everyone.

 

[IDO]

31 minutes ago, West is Best said:

 

This is the same GloSea5 that completely missed the last and only cold spell of the winter, telling us that the signals were for continuation of rampant Atlantic?

The models are zonal with a whopping great Bartlett high to our south, which is THE dominant signal right now and for the immediately foreseeable future. Unfortunately.

We are getting an insight into what the expensive super computers are forecasting, they will feed in far more data and knowledge than any of us, so over the long term their results will be impressive compared to what you hope for. Anyone who expected this winter to be a cold one pre Feb was relying on a SSW, and IMO it is always best not to place hope in one of these every year. Cold will probably come and unfortunately it will be more a cool Spring than a cold winter, as the background cold signals continue to be delayed. 

What at we do know is that the majority of times (see last three years) when a zonal spell is forecast it has great confidence within the models, the fact all the main models are singing the same song is testament to that. Models handle zonal well, they don't handle blocking at all well in comparison.

The cold spell you refer to was not really a cold spell down south, just average winter fare, and by far Jan will be remembered more down here for the dry weather and milder temps and lovely clear blue skies (6c many days during the "cold" spell). Another mild sunny day south of London this morning. 

[Abyss]

Two days ago it was signs of NW/N in early February. Today it's from mid February.  Never a good sign

[West is Best]

1 minute ago, IDO said:

 

The cold spell you refer to was not really a cold spell down south, just average winter fare, and by far Jan will be remembered more down here for the dry weather and milder temps and lovely clear blue skies (6c many days during the "cold" spell). 

I take issue with that. We were building snow'men' in Surrey and when I went through London and up to East Anglia it was bitterly cold.

[Paul_1978]

Interesting update from Ian. Personally a north westerly doesn't hold much interest, as I'm sure is the case for many on here :-(

[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 SATURDAY JAN 23RD 2016

THE CURRENT GENERAL SITUATION   A weak ridge of High pressure will move away East today as a new set of frontal troughs move NE over SW areas tonight and the rest of the UK tomorrow followed by a very mild and moist SW flow.

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

CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across the British Isles ranges from 5000ft across NE Scotland today to 7000ft over the SW rising further tonight to exceed 10000ft for much of the UK tomorrow. With these sort of freezing levels snow cannot be expected.

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

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

MODELS-2 WEEK HEADLINE  Changeable and windy weather with rain at times. Generally mild but some cooler spells in the North with wintry showers at times.

THE GFS JET STREAM FORECAST  The Jet Stream forecast today shows the flow to blow setting up in a NNE direction up the West and NW of the UK for the next few days. It then realigns to blow West to east across Northernmost parts of the UK for the remainder of the period quite strong at times with much of the UK remaining on the milder side of the flow at least until late in week 2.

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

GFS OPERATIONAL The GFS Operational Run today shows no change to the output of late with persistent and often mild and strong West or SW winds across the UK with fast moving bands of rain running through on the flow. High pressure moves up close to the South at times restricting the heaviest and most persistent falls of rain to the North while these areas too see occasional colder interludes with wintry showers albeit very briefly between weather systems.

GFS CONTROL RUN The theme of the Control Run today is the same as the Operational Run in every respect with mild Atlantic winds maintaining relatively mild and changeable conditions for all with rain at times especially across the North and West with some drier spells across the South and East closest to High pressure over Europe.

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 DATA  The theme of the GFS Ensemble Clusters this morning are still very mixed but a 60% pack seem to support High pressure lying to the SW of the UK with a West or WNW flow across the UK with average temperatures and rain at times especially towards the North. 40% show High pressure to the SE of the UK and 20% of this group has High pressure well to the SE with the influence of Low pressure right across all areas of the UK in a cyclonic Westerly flow.

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 strong WSW winds next week in a changeable pattern of fast moving troughs crossing the North with rain at times followed by brief colder interludes with showers while the South stays milder with more occasional rainfall than further North.

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

THE FAX CHARTS The Fax Charts today detail the complexities of the mild SW flow with troughs crossing NE or east on regular occasions alternating mild with chillier conditions in the North while the South stays relatively mild and breezy with rain or drizzle at times.

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

GEM GEM this morning shows windy weather over the next 10 days with winds always coming from a SW, West and later NW direction. Very mild air at first becomes somewhat cooler though not cold later with rain at times still for many though still most prolific across the North where colder conditions could bring wintry showers at times.

http://www.wetterzentrale.de/pics/Rgem2401.gif
NAVGEM NAVGEM today shows a windy but broad mild West or SW flow across the UK across the next 7 days with rain and drizzle at times with some slightly colder more showery conditions across the far North and rather less wet and windy weather at times in the South where some very mild days look likely. 

http://www.wetterzentrale.de/pics/Rnvg1681.gif
ECM ECM today looks very disturbed for the UK over the next 10 days. throughout the period a very strong Jet flow across the UK ensures all areas see spells of sometimes very wet and windy weather with temperatures on the mild side of average. It may become somewhat colder at times with brief interludes of wintry showers between weather systems but overall the most important message from ECM this morning is the return of troublesome amounts of rain again to many western and Northern areas in particular.

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

ECM 10 DAY MEAN The 10 day mean chart shows rock solid support for Low pressure to the North of the UK and a broad trough west of it to Greenland maintaining a strong Westerly flow across the UK with rain and showers at times. While generally mild colder interludes will no doubt affect all areas at times when some wintry showers could affect the North especially in the middle of the period.

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

NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The models this morning continue to portray the Atlantic under complete control of the UK weather over the next two weeks.

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 GFS at 99.5 pts then UKMO at 99.4 pts.  At 3 days ECM is leading with 97.6 pts to UKMO's 96.8 pts while GFS lags behind at 96.6 pts. At 5 days ECM leads with 90.1 pts to GFS at 88.3 pts then UKMO at 88.1 pts. Then at 8 Days GFS has taken over the leading spot from ECM with 67.4 pts to 67.2 pts. Finally at Day 10 ECM is ahead of GFS at 49.4 pts to 48.3 pts respectively. 

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   There remains little differences from the models to that shown of late with absolutely rock solid support from all the main Operational's and many of the ensemble members too for a continuation of the recently set up Atlantic domination we have had to endure for 90% of this Winter. For the next few days it is going to be almost exceptionally mild again with 15C exceeded by many tomorrow, some 22C higher than was the case just 4 days prior. It may be spoilt by cloud and light rain though with the North and West as usual seeing the worst of this. Thereafter the very mildest conditions do seep away somewhat with a more traditional mild then cool alternation of events as various frontal systems run quickly through any one place on the very strong Atlantic flow with gale or severe gales at times. The most alarming thing shown within some outputs this morning is the return of collective rainfall events offering the possibility of a return to flooding issues developing none more so than in the areas already affected this Winter. This may not occur if the passage of troughs is quick but there is some output which shows trailing fronts straddling the UK at times giving sustained rainfall to the places underneath them, something to watch for sure. In the longer term there is still a desire to shift the vortex of Low pressure further to the East towards Scandinavia but unfortunately heights refuse to fall over Iberia leaving the UK in just a rather colder flow from a Westerly point still and Winter still very much on hold as a result. So I'm afraid that it is looking well into February now before any chance of cold returns for the UK and with a flat zonal pattern that exists currently coupled with such a strong Jet Stream again any changes look likely to be slow and arduous.   

Next Update Sunday January 24th 2016 from 09:00