Model Output Discussion 31/03/14 onwards.

[knocker]

The ECM have backtracked on their cyclonic position for the Easter weekend. Watch this space. But given it's a fine balancing act between the cold and warm air confidence must be low on any outcome at the moment.

Edited April 10, 2014 by knocker

[phil nw.]

Yes still a lot of uncertainty from Wednesday in the 12z runs.

As much as i would like the ECM operational to be correct it does go against the Ens means in which both ECM and GFS dig in a cooler north westerly around mid week.

http://www.wetterzentrale.de/pics/Reem1681.gif

http://www.wetterzentrale.de/pics/Rz500m6.gif

again the GFS suite a little earlier on this.

 

The UKMO still shows less of a trough developing affecting only the north at this time. 

[johnholmes]

Been away much of the day and not read any previous posts so apologies if this does not fit in.

The 3 main anomaly charts, see my summary below and their links, have changed quite substantially since the beginning of the week, especially in the 6-10 day time frame (obviously this is now 4 days further on than it was on Monday!), NOAA along with ECMWF-GFS, although here not consistently unlike the NOAA version.

 

Noaa

Change on 6-10 as trough digs down over uk with usual height now at 546dm-lowest for some time, period 16-20 april=easter lead in and to Easter Sunday

8-14 as often case eases the most marked issues down=trough and +ve values but height is only up to 552+dm with flow suggested wly, so unlike a few days  with highish heights and about wly, now suggests wly but bit colder at height and thus probably at the surface, no sign really of the +ve heights indicative of surface heights close to the s of the uk.

So unsettled and coolish is probably the current best suggestion for the lead into and over easter, maybe even rather cold prior to the actual weekend?

 

and comments on the ECMWF-GFS for today

thur10apr

Ec-gfs

Differences between models again, gfs showing quite marked troughing uk area with ec no(the 12z version has though=a marked trough and cut off beneath it!)

 

http://mp1.met.psu.edu/~fxg1/ECMWF_12z/hgtcomp.html

12z version

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

 

http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

Edited April 10, 2014 by johnholmes

[Cloud 10]

Looking at the 12z runs from ecm and gfs again at just 96 hrs seems to reveal the bias in 

these two models with the ecm being very amplified with the jetstream and the gfs

being much flatter.

 

ecm..  gfs..

 

 

latest 120 hrs fax chart not supportive of gfs.

 

Edited April 10, 2014 by Cloud 10

[Frosty.]

Met office still going with a change to relatively colder and unsettled weather from the north west by mid next week with the possible exception of the south east corner where the residue of high pressure may persist. Since the ecm has been, shall we say, under performing since november, I still believe we are on course for a cooler, breezier and wetter spell later next week. The north of the uk nowhere near as warm or settled as further south during the entire forecast period.

Edited April 10, 2014 by Frosty.

[Captain Shortwave]

The recurring theme this Spring has been for any cold unsettled weather that has been forecast has fallen like a house of cards in the wind. Could the ECM being that far off the mark at even 4 days out. Also given the model today has steadily moved away from the cooler/unsettled trend, I would be very surprised if it had been led astray.

Must add even though the UKMO does not agree with the ECM, it very much refuses do go in line with the American models. 

The morning suite will shed some more light I think. Very much still in the air. 

[davehsug]

Looking at the 12z runs from ecm and gfs again at just 96 hrs seems to reveal the bias in 

these two models with the ecm being very amplified with the jetstream and the gfs

being much flatter.

 

ecm..ECM1-96.gif  gfs..gfs-0-96.png

 

 

latest 120 hrs fax chart not supportive of gfs.

 

fax120s.gif

It would be difficult to get to any meaningful Northerly from that fax. Although FI has been ridiculously short these last few months. Even this week isn't really panning out how it looked on Sunday's countryfile forecast. I at last felt confident enough to say that Easter didn't look great in work this morning, then I looked at the 00z ECm lol!

[snowmadchrisuk]

Well the GFS continues this morning , with what can only be described as the Coldest Northerly for at least a year , and it now creeps further into High Res .Snow even for the South from some of the GFS charts this morning , if it comes off quite a spell for late April..

 

Edited April 11, 2014 by snowmadchrisuk

[Captain Shortwave]

The recurring theme this Spring has been for any cold unsettled weather that has been forecast has fallen like a house of cards in the wind. Could the ECM being that far off the mark at even 4 days out. Also given the model today has steadily moved away from the cooler/unsettled trend, I would be very surprised if it had been led astray.

Must add even though the UKMO does not agree with the ECM, it very much refuses do go in line with the American models. 

The morning suite will shed some more light I think. Very much still in the air. 

And the GEM caves in and says no to any cooler and unsettled weather and only breaks things down by Easter Sunday

Good Friday and Easter Saturday would be rather warm with temperatures into the low 20s in places. Cooler and more unsettled during the later part of the weekend but nothing more than a return to average(ish) westerlies.

UKMO is similar to yesterdays and also says no to low pressure diving south east and bringing in a northerly.

GFS whilst it still says yes to a northerly is beginning to show signs of amplifying the ridge over the UK into the beginning of next week (more akin to other models), this could be the start of a slow and painful backtrack. If the ECM sticks this morning, it will be very likely that all signs of the cold northerly by the end of next week will have disappeared.

[Frosty.]

The Gfs 00z op run shows a transition to colder and more generally unsettled weather from the north west by the middle of next week with a blast of showery polar maritime veering towards arctic for a time by the end of next week, at least for scotland with snow showers and a few very frosty nights followed by an atlantic ridge toppling south eastwards cutting off the arctic flow but quickly followed by another surge of cold, showery weather from the north west, and then another by the very end of the run, again it's northern britain and especially scotland which bears the brunt of this. For the southern half of the uk, high pressure has much more of a say, occasionally building in across the south with lots of fine, sunny and mild / warm days but with some chilly nights and ground / slight air frosts...no back down from the gfs

Edited April 11, 2014 by Frosty.

[Frosty.]

The Ecm 00z op run delays the change by a day or so compared to the gfs with the in situ anticyclone next week proving to be rather more stubborn than the gfs shows but eventually colder and more unsettled weather piles in from the north west, however, the south has a mild / warm week, the coldest and most unsettled, windiest weather is bottled up across the north west of the BI, the ecm tries to pull the trigger and enable a much colder and disturbed pattern to invade from the north west atlantic but it hits a brick wall as it comes up against higher pressure across mainland europe and literally runs out of steam, most of the pent up energy ends up digging south into the mid atlantic as the jet buckles. I would say the ecm is more of a half way house, perhaps not even that with only the north western half of the uk feeling the change most of all whereas the gfs is currently far more progressive in introducing a colder, unsettled spell later next week to all areas...which model will be right?  the ecm has no form, an interesting met office update coming up me thinks..MOGREPS holds the key.

Edited April 11, 2014 by Frosty.

[Summer Sun]

GEM showing a nice warm start to the Easter weekend this morning it may not be perfectly dry but at least it wouldn't be cold

 

 

By Easter Sunday the east holds onto the warmer air but it becomes slightly cooler from the west as it turns more unsettled for all

 

 

By Easter Monday the SE holds onto warmer air for one more day

 

[Summer Sun]

Interesting run from UKMO again this morning with it once again showing high pressure lasting longer than we initially thought

 

After a unsettled spell in the north over the weekend we get a short live north westerly on Monday

 

 

But after that its a case of high pressure dominating

 

Edited April 11, 2014 by Summer Sun

[knocker]

Looking at this mornings ECM doesn't really make us much wiser. We are still looking at the cold air to the north and warm to the south with a transient ridge on Wednesday. By the weekend it's a north/south split with fresh westerlies. But this could still go either way I suspect with my limited knowledge. A trough with a plunge of colder air which seems favourite at the moment or a build up of heights from the south. Take your pick and if anyone asks me what the weather is going to be like over Easter I'll just say I'll phone a friend.

Edited April 11, 2014 by knocker

[vladthemert]

I dont know whether im coming or going with the models playing hokey cokey with its cold or hot game

 

Incidently our rag said long term met talks of a 2 month heatwave upto june.  Surely too early call it almost as bad the national calling for next ice age every week a cold snap due.  

[Spikecollie]

I notice Météo France are progging a breakdown with thundery showers and thunderstorms from Wednesday next week over there - looks like it could be an action packed start to our Easter break if it comes off, but I'm not sure it's exactly what we want...

[draztik]

Looking at the ensembles this morning, very little has changed with regards to the cooler outlook twrds Easter. ECM ens shows the UK to be under a broad westerly pattern, with NWesterly incursions at times, this would bring below average conditions nationwide; temp chart continues to show a negative anomaly for the UK over Easter.

days 7-12 temp anom / ecm 0z

GFS, too keeps with this cooler theme, with temps below average into the bank holiday and beyond.

days 7-12 temp anom GEFS 6z

and just because we can, cfs ensembles trending below average into May.

May Outlook / cfs ens temp anom

[Chris K]

Looking at the ensembles this morning, very little has changed with regards to the cooler outlook twrds Easter. ECM ens shows the UK to be under a broad westerly pattern, with NWesterly incursions at times, this would bring below average conditions nationwide; temp chart continues to show a negative anomaly for the UK over Easter.

days 7-12 temp anom / ecm 0z

GFS, too keeps with this cooler theme, with temps below average into the bank holiday and beyond.

days 7-12 temp anom GEFS 6z

and just because we can, cfs ensembles trending below average into May.

May Outlook / cfs ens temp anom

 

Well....I suppose it is better to have it now than in Summer....*gulp*

 

The trend for the SE to see the better weather still seems evident in the models, but with the migration of high pressure from the azores seemingly wanting to move into Europe and beyond, the further East it gets I would assume then that the door opens more easily for Low pressure to follow in from behind.

 

It still looks a bit uncertain as to how the High pressure behaves once stretching across us into Europe. Some still go for it sticking close enough to allow a milder contiental feed to drift across the Southern half of the UK, whereas others allow the Low pressure influence more of the UK from the NW, bringing cooler unsettled conditions to a more widespread area...

[Summer Sun]

Once again this afternoon its UKMO which continues to go for a more settled outlook well next week

 

 

Interesting trend from UKMO it has to be said GFS agrees to t96 but t120 and t144 is more unsettled

 

If UKMO is right it could become quite warm on Wednesday especially for the south with a nice southerly flow

 

Edited April 11, 2014 by Summer Sun

[Cloud 10]

Interesting how the GFS 12z has "found" some amplification in the jet-stream for its

Monday chart compared to yesterday.

 

yesterday..  today..

 

yesterday..  today..

 

Must have been lost behind the sofa. 

[Captain Shortwave]

Looking at the ensembles this morning, very little has changed with regards to the cooler outlook twrds Easter. ECM ens shows the UK to be under a broad westerly pattern, with NWesterly incursions at times, this would bring below average conditions nationwide; temp chart continues to show a negative anomaly for the UK over Easter.

days 7-12 temp anom / ecm 0z

GFS, too keeps with this cooler theme, with temps below average into the bank holiday and beyond.

days 7-12 temp anom GEFS 6z

and just because we can, cfs ensembles trending below average into May.

May Outlook / cfs ens temp anom

I agree, nothing has changed..... the extended ensembles continue to go cold and continue to be wrong. I mean if they were right then March would have been a colder than average month and the first half of April likewise. No need to digress any further.

The GFS continues to backtrack, whilst some may disagree, look at midweek now. The GFS now has the high in the same location the other models did a day ago. Very poor and frankly it's clearing heights far too quickly still in my opinion. UKMO is very consistent with it's output over the past couple of days. 

Heads up for Wednesday, could be a very warm day potentially. Especially over England.

Edited April 11, 2014 by Captain shortwave

[ANYWEATHER]

I agree, nothing has changed..... the extended ensembles continue to go cold and continue to be wrong. I mean if they were right then March would have been a colder than average month and the first half of April likewise. No need to digress any further.

The GFS continues to backtrack, whilst some may disagree, look at midweek now. The GFS now has the high in the same location the other models did a day ago. Very poor and frankly it's clearing heights far too quickly still in my opinion. UKMO is very consistent with it's output over the past couple of days. 

Heads up for Wednesday, could be a very warm day potentially. Especially over England.

No done deal yet with the gfs or indeed other models , except some unsettled and colder conditions over Easter, but how cold and how unsettled still remains out to the jury. Ive known the gfs for instance, to show a strong signal for colder weather, then drop it, then bring it back much nearer the reliable timeframe....  

[gottolovethisweather]

No done deal yet with the gfs or indeed other models , except some unsettled and colder conditions over Easter, but how cold and how unsettled still remains out to the jury. Ive known the gfs for instance, to show a strong signal for colder weather, then drop it, then bring it back much nearer the reliable timeframe....  

 

Whilst I agree, Anyweather, I don't see an incursion of anything particularly cold further South than say the Midlands, in fact most probably we will continue on the drying trend which I am personally happy to see in spite of being a coldie at heart. The chase for phantom Northerlies is getting tiresome as it has done over the last six months to be fair, the coldest synoptics have never looked likely to threaten our shores partly due to that raging Jet and the Polar Vortex shenanigans. If we have to receive some rain IMBY, I would rather it came from a Thundery breakdown given time is ticking by, in fact that is now a distinct possibility it seems. I stated the following in my post from the other day and ..........

 

http://forum.netweather.tv/topic/79573-south-westcentral-southern-england-regional-weather-discussion-27214-18z/?p=2954887

 

The Northwest/Southeast split pattern continues on unabated, bar a weakening frontal system occasionally effecting the Southern section of the UK.

Edited April 11, 2014 by gottolovethisweather

[ANYWEATHER]

Ecm and Gfs look distinctly similar by Good Friday , Im sure there will be lots of rollercoaster rides before we get to that time frame!  

[Winter Cold]

Very quiet in here tonight to say we MIGHT be looking at our best chance at seeing a snow flake in the whole of the last 6 months over the Easter period!

 

Best thing is, we'll all be off work so we can sit and watch the snow fall, if it happens. My fingers are crossed anyway....

 

Lots of cold air here on tonights ECM, spilling in from the North West

 

GFS looking similar too.