Model output discussion - 20th Feb onwards

[Nouska]

1 hour ago, Man With Beard said:

On the GFS 12Z the strongest winds stay away from the coast.

The latest Argepe, however, is another story - it tries to develop what I imagine would be a sting jet late Monday Morning, with gusts over 90mph in off the Bristol Channel. 

UKMO 12Z output for 10 metre winds.

    

Source.    http://meteocentre.com/models/explorateur.php?lang=en&map=fr&run=12&mod=ukmet&stn=PNM&comp=1&run2=12&mod2=ukmet&stn2=PNM&hh2=042&fixhh=1&stn2_type=prog&mode=latest&yyyy=latest&mm=latest&dd=latest&hh=000

[Singularity]

http://www.theweatheroutlook.com/twodata/chart.aspx?chart=/charts/ecm/192_mslp850.png?cb=311

The low over Iberia in 5-6 days time is causing the models some trouble. This ECM 12z run shows us the scenario in which it gets trapped in situ and drives a plume of unseasonable warmth up toward the uk.

This model has been toying with this on and off for a good few days now - and GFS has had a few goes at it too but often a bit later in time. 

The above chart could produce 23*C or so in the SE if there is a good bit of sun.

Edited March 26, 2016 by Singularity

[Frosty.]

I would love to see an early plume like the Ecm 12z op shows this evening with temps soaring into the mid 70's F. These are charts which really whet the appetite for the next 5 months!

[Tim Bland]

Will be interesting to see ECM mean later. Not a single gefs member supports the warm southerly flow so it's unlikely IMO 

[Frosty.]

2 minutes ago, Tim Bland said:

Will be interesting to see ECM mean later. Not a single gefs member supports the warm southerly flow so it's unlikely IMO 

And yet there is mention of warm spells in the met office update which would tie in with what the Ecm 12z op shows which is good news as we look ahead to April.

[Milhouse]

Lots of options on the table for how April will begin. the ECM throws in a lovely sumemrlike Southeasterly while the GEM bullzodes the Atlantic back in without giving high pressure time to build. I believe we will end up with a middle of the road scenario like GFS version of events. Settled for a time with temps in the low to mid teens.

[abruzzi spur]

12 hours ago, Steve Murr said:

If we look at this set up & then compare October 1987 there are a lot of similarities-

I havent looked on the METO page but there should already be amber warnings out & sunday overnight into monday may eventually be upgraded to red...

S

Flippin 'eck Steve, are you sure?  Would be amazed.   MO has been steady with yellow all day, now we have smaller areas in the warning zone, today was properly lively in Reigate for about 20 minutes as the squall line went through.  Tomorrow  suggests nothing of interest,  Monday lively again but, really, do you see a red warning? i can't see it.  if I'm wrong then I'll be back to say well done.

[Paul]

Nick's put together another really interesting synoptic analysis blog - looking at tomorrow and Monday

http://www.netweather.tv/index.cgi?action=news;storyid=7251;sess=

[johnholmes]

Currently the exit point looks like being he Lincs area, with the probability of it being south rather than north of that county. So about back to what looked most likely 48 hours ago. 24 hours ago Newcastle or the Yorks coast seemed most likely.

[Singularity]

The differences between ECM and GFS arise from the former firing the jet SE from the mid-Atlantic for day 8, heading south of a ridge over Norway, while the latter powers the jet east, pushing a trough across to the vicinity of the UK by day 9.

This has serious ramifications going forward, because there is a strong signal for the pattern to become very amplified from around day 9 or 10, at which point the position of the trough determines whether the UK is on the warm or cool side, and of course how unsettled - or not - the conditions are. 

ECM reinforces the theme of the polar jet diving down south of Iberia, while GFS has forced the pattern a great deal further east, with chilly results for the UK:

  

As contrasts go, that's a strong one. The ECM solution is a beauty although it does threaten to turn conditions cool and murky from the east a few days down the line. I'd be alright with a trade-off of a few days in the high teens to low 20's for the same number with low cloud off the north sea and temps barely making double digits, provided two of the former spanned the weekend 

[knocker]

The ecm this morning has Katie whipping across the UK during the early hours. At 00z it's over the woodshed and moves rapidly NE to exit over the Lincolnshire coast by 12z. The strongest winds will be in the channel but gusts 70+ kts could still impact the south coast and the SE.

[Polar Maritime]

NetWx-SR take on the wind gusts & Low track for Easter Monday.

Edited March 27, 2016 by Polar Maritime

[Frosty.]

The Ecm 00z op run shows a nice warm up across the south of the uk during next weekend into the early part of the following week with very pleasant conditions for early April.

[knocker]

The north Pacific blocking and the deep cold trough over N. America

is having considerable influence on our weather as forecast with the anomalies.

Both the the GEFS and ECM have a trough orientated SE from this, acting as LP channel to the trough running south into Europe over, or adjacent to the UK. I mention adjacent because the ecm has it running to the west which makes a considerable difference to the UK outlook. Although the weather continues to be unsettled the ecm interpretation would likely suggest LP to the SW, with heights building over Scandinavia, a warm flow from a southerly quadrant would ensue so most of the varying weather likely in the southern half of the UK. The GEFS more likely to have the LP over the UK and thus a tad cooler.

In the 5-10 period the ecm moves the tough east over the UK veering the upper flow westerly thus becoming more unsettled generally. The GEFS not dissimilar although it does make rather of the HP nudging from the SW.

Edited March 27, 2016 by knocker

[Milhouse]

Some unseasonably warm temperaures getting tantasingly close to the UK on the GFS 12z. Just goes to show what the better ECM would be capable of delivering.

[Frosty.]

It could get really interesting next weekend according to the Gfs 12z op run with an unseasonably warm plume across the near continent with temps in the mid 70's F and mid to high 60's F across the southeast / east Anglia next weekend, a bit more westward adjustment would see the SE becoming very warm, even the risk of a few thundery showers drifting up from the continent too. Looking further ahead, the Azores high ridges across the UK into the following week with pleasant warmth in the mid teens celsius and then it becomes colder and more unsettled with even a chance of snow on northern hills..it's a typical mix of early spring weather with something for everyone.

[knocker]

The GFS just loves cyclogenisis.

 

[ANYWEATHER]

Evening to One and All!! At last we are looking at a Normal Spring From late March we get April Showers....

[Man With Beard]

I note that both EURO4 and GFS have upped south coast wind speeds for tonight by 5-10 mph on their latest runs

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2016/03/27/basis12/ukuk/ismh/16032800_2712.gif

 

I think we'll top 80mph easily on the south coast tonight, somewhere. The GFS suggests, dare I say it, even 90mph is not impossible??

[Eugene]

6 hours ago, Milhouse said:

Some unseasonably warm temperaures getting tantasingly close to the UK on the GFS 12z. Just goes to show what the better ECM would be capable of delivering.

 

Average temps and rainfall?

[Singularity]

24 minutes ago, Man With Beard said:

I note that both EURO4 and GFS have upped south coast wind speeds for tonight by 5-10 mph on their latest runs

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2016/03/27/basis12/ukuk/ismh/16032800_2712.gif

 

I think we'll top 80mph easily on the south coast tonight, somewhere. The GFS suggests, dare I say it, even 90mph is not impossible??

Yes the storm obs are suggesting that it is at least as strong as ARPEGE kept insisting it would be. 

The strong winds associated with the wrap-around show up far more clearly on the 18z GFS, thanks to both a deeper low and a shift north in the track.

Watching for a a potential sting jet. The dry air slots are becoming apparent but I'm not sure about the warm conveyor.

[Cheshire Freeze]

7 minutes ago, Singularity said:

Yes the storm obs are suggesting that it is at least as strong as ARPEGE kept insisting it would be. 

The strong winds associated with the wrap-around show up far more clearly on the 18z GFS, thanks to both a deeper low and a shift north in the track.

Watching for a a potential sting jet. The dry air slots are becoming apparent but I'm not sure about the warm conveyor.

The Arpege has totally owned the GFS here by the looks of it.

[johnholmes]

this link gives the strongest wind gusts and rainfall

http://www.weatheronline.co.uk/weather/maps/current?LANG=en&CONT=ukuk&LAND=UK&REGION=0003&SORT=3&UD=0&INT=06&TYP=windspitzen&ART=tabelle&RUBRIK=akt&DATE=1459144800&CEL=C&SI=mph

The centre looks now to exit around the Wash. Much as predicted about 72 hours ago by UK Met if my memory is correct?

well the link below shows it in fact went just south of the Humber

http://meteocentre.com/analyse/map.php?map=UK&date=2016032808&size=large&lang=en&area=eur

Edited March 28, 2016 by johnholmes

[knocker]

A serious disagreement between the GEFS and ecm vis the 5-10 anomalies. The GEFS has the trough just to the SW of the UK running south to the western Mediterranean With height rises over Scandinavia and ridging in the western Atlantic. This would incline to more unsttled weather in the west and south but with the flow from the southern quadrant temps would be pleasantly warm.

The ecm is having none of this with a trough running from the vortex N. Canada SE over the UK suppressing the ridging in the western Atlantic. This would lead to a more unsettled period generally with a cooler Pm WNW airstream.

The jury is out.

Edited March 28, 2016 by knocker

[stodge]

Afternoon all

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240

As Knocker implies, still all to play for and the Ensemble members show a clear divide between the Atlantic returning and some form of blocking which is either driven by HLB or, and this has been the interesting development for me, an increasing trend for lowering heights over Europe as LP moves up from Africa. The Control shows this as an example.

One or two members holding out for height rises over Greenland and an Arctic outbreak as well.

It's one of the more interesting times of the year for those of us liking to see unusual synoptics and while the outcome of the war may not be in doubt, the "battle" between spring and winter isn't yet over and as today has shown for some, even snow can't yet be ruled out.