Model Output Discussions 18z 31/01/2016

[Ali1977]

Should not grumble with better looking charts, but I wish the WAA at day 6 was SE/NW rather than the opposite - we know what follows a few cold days - more wind and rain!!!

Edited February 8, 2016 by Ali1977

[Daniel*]

4 minutes ago, Weather of Mass Disruption said:

Really dislike marginal situations as from experience we (IMBY) always end up on the wrong side and just get loads of cold rain... 

Unfortunately in the UK marginal situations tend to give way to the most heaviest/disruptive snowfalls.

This run is good if snow is what you're after most particularly for midlands northwards no deep freeze but it's substantially better than the 'norm' with multiple potential snow events.

[Banbury]

3 minutes ago, Daniel* said:

Unfortunately in the UK marginal situations tend to give way to the most heaviest/disruptive snowfalls.

This run is good if snow is what you're after most particularly for midlands northwards no deep freeze but it's substantially better than the 'norm' with multiple potential snow events.

Associated ppn charts don't have that much snow North

[Timmytour]

6 minutes ago, Ali1977 said:

Should not grumble with better looking charts, but I wish the WAA at day 6 was SE/NW rather than the opposite - we know what follows a few cold days - more wind and rain!!!

Just trying to imagine how things might look on tomorrow night's pub run if that low off the eastern seaboard doesn't actually develop.....

 

[shaky]

No change towards ecm on the gfs 18z!!infact its even more slidey than the 12z!!!lets hope for a better ecm in the morning!!!

[Snowy L]

18 minutes ago, Timmytour said:

Just trying to imagine how things might look on tomorrow night's pub run if that low off the eastern seaboard doesn't actually develop.....

 

Surely we should want that low to develop and go above that Azores high to continue the slider conveyor belt. All mid-latitude blocking does is provide an escape route for high-latitude blocking to leave the high latitudes.

[weirpig]

decent bbc weather forecast   met keeping close eye on developments  of possibility of snow.  All good

[Frosty.]

The way things are going, I wish it was the weekend already because it looks absolutely fascinating with significant snow potential on the Gfs 18z..even in the very short term there looks like being some hill snow around tomorrow, even in the south! Temperatures then generally falling away later this week and through the weekend, close to ice days for some with accumulations..a forecasting nightmare but for snow starved coldies...lamp post and radar watch later this week!

[syed2878]

4 hours ago, nick sussex said:

Do you mean the NCEP one? I'm still waiting for that to update, it should be out later this evening. The more in depth one is out tomorrow evening.

The link for tonights update is here, scroll down to expert discussions and the PDF  update.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml

On the same page you'll see Global Tropics Hazards and Benefits Outlook, link to that and this gives you a more in depth discussion which is updated tomorrow.

If you missed it Singularity did a great in depth post on the previous page. Currently theres a divergence between the ECM and GEFS.  Thanks nick.

 

 

[snowice]

ECM going the way with Gfs at 120hrs slider -7uppers in North pushing south 

[Man With Beard]

Cross model agreement on the slider scenario for T96-T144, with ever increasing cold being sucked in from the east.

I don't think it's wishful thinking, but I would be very sceptical of the lack of precipitation on GFS hi-res charts. This set-up is made for snowfall - it's an Atlantic low being influenced by an easterly wind. I expect we will be speaking snow on Sunday/Monday, locations to be decided but it will not be just for the few. 

[SMU]

Yes morning all

cross model agreement at 120 now

with the UKMO 1 full day ahead of the ECM yet again - same scenario as Jan

snow for some for the weekend

 

Could well be winters only hurrah !

nB the 18z & now the 00z ECM chops up that mega low sending energy SE

could we squeeze more snow from the NW

s

 

Edited February 9, 2016 by Steve Murr

[Chris K]

14 minutes ago, snowice said:

ECM going the way with Gfs at 120hrs slider -7uppers in North pushing south 

GFS 0z lowers risk of snow though in my opinion (Although parts of Wales and northern UK still see some from it - more of a wintry mix further South)

We still get a decent northerly cold blast but it remains a toppler at this stage.

 

[chris55]

ECM comes on board regarding the overall pattern in the shorter range.

The first slider doesn't really get going on the 00z runs (Friday) and what is there skirts to the south.

However we do get a few more shots into the weekend as other lows attempt to push in.

some frontal snowfall looks odds on for some before Monday.

 

 

[Ali1977]

Some very interesting Ens out there for last 3rd of Feb, this weekend may not be the only chance of a cold spell.

[IDO]

A colder flow over the weekend as the transient ridge topples but the slider low after T100 modelled differently by the big boys with the GFS now blowing it up and now a washout rather than a snow event, though subject to change:

So although other models are better it does look marginal. Maybe it will firm up in the next few days. 

Further on nothing blocked on the hi-res and backed up by the vast majority of GEFS right out til D16. The mean T850s stays below 0c for the next 16 days but no sign of any fierce cold, that is elsewhere on our latitude:

London ENS: 

Seasonal stuff so potential for something wintry to crop up and obviously better than December's set up.

Dr Cohen's blog with respect to the SSW suggests East US and East Asia will get the main pulses of cold into mid March. W Europe depends on the Atlantic blocking and we could end up mild (MLB) or cool/cold (HLB), but no real sign of any sustained US type cold, though still trop to strat propogation forecast in the next week or two so no final conclusions yet. So anything after D10 on the models even less relevant than normal as we await the last piece of the Winter jigsaw to fit into place.

 

[shaky]

Where are all the posters this morning!!we finally get the ecm to agree and now no one wants to post lol!!!!a bit of fatigue kicking in maybe!!!anyway ecm suddenly wants to slide the lows for this weekend which is excellent news!where the snow falls is anyones guess!!

[Paul_1978]

1 hour ago, Chris K said:

GFS 0z lowers risk of snow though in my opinion (Although parts of Wales and northern UK still see some from it - more of a wintry mix further South)

We still get a decent northerly cold blast but it remains a toppler at this stage.

 

Yep the weekend and Monday have got the potential to be brilliant, but as it stands ultimately it all only lasts 3/4 days before the Atlantic wins over. Still, looking forward to seeing how it pans out though!

[Nick F]

After the wild weather in the south yesterday, to me it now looks like a fairly quiet period of weather for the rest of the week for many, bright and cold in the north, bright and cool in the south - though some showers around, mostly around coasts, wintry in the north with snow over higher ground. 

00z EC and GFS high res show a Slider low across southern areas progged for Saturday could bring some snow across Wales, The West Country, The Midlands and perhaps central  S England - particularly as the low clears ESE into northern France and cold air undercuts from the north. Way off though and track of this low may change. Apart from Saturday, not a lot going on other than wintry showers near coasts, some overnight frosts but as should be expected this time of year. The cold northerly Sunday onwards probably fairly dry, other than wintry showers on windward coasts.

As the northerly relaxes high pressure building in could bring some hard frosts, models maybe too progressive trying to bring the Atlantic low pressure influence back in from the West too next week.

 

[johnholmes]

The latest Met Fax charts show how complex Friday into Sunday could turn out to be. Overall one would expect rain for most low lying areas with having had no real cold prior to the event. However, light winds and moderate rain in this type of situation can fairly easily turn to snow (evaporative cooling process) so one or two areas might get a white surprise. Then of course the uncertainty of just where moderate rain might fall-not known until 12 hours possibly less before the event. So an interesting spell for the southern half of England as folk watch the twists and turns involved.

[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 TUESDAY FEB 9TH 2016

THE CURRENT GENERAL SITUATION   A westerly airflow across the UK will ease later and veer NW behind a weakening trough moving South over England and Wales tonight. Another trough near SE England will move away East this morning.

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

 CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across the British Isles is now rather lower than of late with levels between 2000 and 4000ft across the UK. There will be some snowfall at times on hills above 1000ft but as usual mostly over adjacent hills and mountains to coasts to the West and NW.

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

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

MODELS-2 WEEK HEADLINE  Mostly unsettled with rain or showers. Fluctuating temperatures with some snow at times over higher ground especially in the South at the weekend.

THE GFS JET STREAM FORECAST  The Jet Stream remains generally to the South of the UK over the next 4-7 days with the UK covered by Low pressure. Later next week the flow becomes more variable and generally further North than currently before returning a point just South of the UK in a West to East flow late in the period.

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

GFS OPERATIONAL The GFS Operational Run today shows Low pressure under control for another week at least with a slack few days of winds to come with chilly air and scattered showers before Low pressure slips ESE across the South towards the weekend into the cold air and giving rise to a messy mix of rain and snow across the South over the weekend. Then next week sees cold and showery weather under Northerly winds give way to fine and frosty weather for a time. Then through the second half of next week milder westerly winds return with rain at times across the North and West with wet weather probably extending to all areas later with Westerly gales at times.

GFS CONTROL RUN The theme of the Control Run is also very unsettled with chilly and showery weather between now and Friday before Low pressure slips SE across the SW and brings rain and snow into the UK from the SW over the weekend. This then sets up a chilly week next week too with another major Low pressure sliding SE across the heart of the UK with severe gales and heavy rain and snow followed by colder air and wintry showers again midway through the second week. The belated High pressure ridge on this run is much more shallow and short-lived as Low pressure from the NW brings renewed cloud and rain again by the end of the period.

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 indicate High pressure to the SW in 14 days time with winds across the UK likely to be blowing from between West and North. Changeable conditions look most likely with most members indicating varying degrees of how much Low pressure to the North and NE affects the UK with their attendant rain or wintry showers.

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 unsettled conditions continuing across the UK well into next week. Low pressure is shown to slide SE across Southern Britain at the weekend and with cold air by then well ensconced across the North of the UK a messy mix of rain and snow will affect the South of the UK in particular over the weekend before all areas become cold and showery early next week ahead of a cold and frosty ridge of High pressure likely by midweek

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

THE FAX CHARTS The Fax Charts today illustrate small changes involving the movement further South of the Low pressure area towards the weekend moving ESE across the far SW and France. The complex trough structures currently producing showers close to coasts and those associated with the Low pressure towards the weekend over the South and SW will increasingly give rise to the risk of snowfall in places as the air across the UK becomes slowly colder.

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

GEM GEM today shows another week or so of unsettled weather and with temperatures rather lower than of late and with Low pressure taking a more Southerly track close to the South over the weekend rain and increasingly likely snow will affect the South at times before a short spell of NNE winds and wintry showers become the precursor to an equally short frosty and cold period. Then later next week milder and stronger Westerly winds are re-introduced with rain at times returning to many areas.

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

NAVGEM NAVGEM today keeps the drier phase early next week rather shorter than some of the rest of the output with the cold and unsettled weekend with rain and snow further North than the rest of the models. This phase of weather is then displaced by a weak ridge of High pressure with the chance of frost before wind and rain from off the Atlantic returns along with milder air to all areas later next week.

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

ECM ECM today is probably the most complex of the lot this morning making a real dog's dinner of the prospects for the weekend with a very unclear boundary between mild air to the SW and cold and unstable air across the UK. Low pressure moving ESE on this run at the weekend seems quite shallow with a messy mix of rain and snow over the South for a time before it all slips away East over Europe leaving  a 24 hour spell of cold Northerly winds with wintry showers near coasts before frosty fine weather for another 24 hours become displaced by less cold Westerly winds and rain at times gradually pushing in from the West erratically towards the end of next week.

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

ECM 10 DAY MEAN The 10 day mean chart today shows a similar pattern to that shown yesterday with Low pressure likely to lie near Iceland and a trough down across the UK and NW Europe with High pressure near the Azores. West or NW winds with rain or showers almost everywhere continues to be the main message given by this chart again today.

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

NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS There are some hints that following the ridge of High pressure early next week a change to a more Low to the North High to the South pattern develops.

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 97.6 pts to UKMO's 97.0 pts while GFS lags behind at 96.5 pts. At 5 days ECM leads with 90.8 pts to UKMO at 88.8 pts and GFS at 88.1 pts. Then at 8 Days ECM has the leading spot from GFS with 67.0 pts to 63.9 pts. Finally at Day 10 GFS leads today at 48.6 pts to ECM's 48.0 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  At least things are looking a lot less stormy on the charts this morning than were projected some days ago. Nevertheless there is plenty of diversity shown on all the output this morning with wide ranging conditions day to day shown for all areas over the next few weeks with temperatures on the cold side for the next week then returning to a more yo yo pattern again later. In the short term we are settling into a quieter period of weather and quite chilly too with some showers especially near coasts and these could well be wintry over the hills. Then towards the weekend all eyes will be on developments to the West of the UK as Low pressure areas look poised to slip ESE across the SW of the UK on their way down over France. Engaging the cold air across the UK will be watched with interest as this could result in some snowfall across the South but to what point and location is yet to be decided. However, whatever happens the weekend looks cold and raw for many with that chance of cold rain or snow across the South. It doesn't look the start of a long cold spell though because the whole complex shifts away East over Europe next week with just a day or so of cold North winds and wintry showers and night frosts displaced later by a return of a more Atlantic based less cold Westerly pattern with rain or showers at times especially across the North and West. The above is the most likely sequence of weather events over the UK in the next two weeks but I should stress the situation is very complex and subject to change given that the prospects for this weekend and the exact course of Low pressure then is yet to be nailed down giving potential changes to the pattern thereafter. So a typical February mix of weather in the offing this morning with almost something for everyone over the next few weeks though hopefully much of what happens will be rather less dramatic than some of the events the UK has seen in general this season so far.        

Next Update Wednesday February 10th 2016 from 09:00

Edited February 9, 2016 by Gibby

[carinthian]

Not sure how far North and East the precipitation at the weekend makes in roads. The slider low could even make a further track further south than this mornings . One to watch , could produce some surprise snowfall in places further south as JH as indicated. However, I have a feeling height rises to the NW will push the main precipitation into France. Good weather watching this week and looks like plenty of snow heading for the Alps and a wintery end to the week over much of the UK. Most medium long range forecasts, including UKMO favour a return to a rise in height to the south again with a milder outlook, however models may now be too progressive to bring back the milder Atlantic flow. We will see.

 C

[Cloud 10]

A comparison of the ECM between yesterday and today.

 

 

 

Also a comparison of last night's fax chart and the updated one this morning,with the colder air further south,and everything else with it.

 

old..new..

[The Weather Dragon]

My opinion - after 11 years of roaming these forums - the best cold has come from short term upgrades - not from looking deep into fantasy island - which at times can be 120-144 onwards

[tight isobar]

Well the slider LP could just become a coastal 'clipper' with a wintry mix on the coast's and weak northern most snow precipitation on its vwry leading edge. 

However @3-4 days out even as a gambling man...I wouldn't take the punt. As with sliding scenarios any incur/correction northwards could see dilution of air and some moderate/heavy snowfall over a large quadrant of land.far to early given the obvious miss-modeling @early range!..but at least both ample opportunity and something of interest in the winter of bore. ....thus far!