Spring Model Discussion 21st March 2013 006z onwards...

[Summer Sun]

Well all in all not a bad run from GFS positive steps tonight in that we slowly start to loose the coldest uppers from later this week in the south west first

By Easter Saturday the coldest uppers start to relax further north

This process continues through Easter Sunday

Easter Monday see's the 0c uppers head further south again but its only parts of Scotland and maybe Northumberland which are left with the coldest uppers

Temperatures should be higher than of late someone may hit 10c but 6c to 8 or 9c looks likely along the south coast (5c to 7c widely across the country)

Into April and the coldest uppers have relaxed still chilly for the time of year but temperatures would at least be higher than they have been of late

So all in all not too bad the positive step is the coldest uppers finally look like relaxing starting later this week and continuing for most through the weekend temperatures would continue to be below average but given the stronger sunshine now it wouldn't feel too bad in any sunnier periods

Edited March 24, 2013 by Gavin.

[Captain Shortwave]

@Gavin

Well it looks like the Easter weekend is again looking like being cold for most if not all with the chance of showers and longer periods of snow for lucky/unlucky locations. GFS looks the mildest option with the GEM/UKMO keeping things very wintry for the time of year.

[Derecho]

GFS keeps the cold going to the end of the month at least with the 12Z, if we get a breakdown from the low to the SW it would bring a big risk of more flooding... so hopefully such a scenario won't occur. (although this run is rather wet but not especially so)

The 12z attempts to bring the sort of cold weather breakdown I'd prefer, a build of pressure to our east and no stalling fronts, come April and I think even I'm looking for signs of some warmth in the output now. (the 12z also still has low minima though).

I wouldn't be surprised for the cold to stick until the end of March though. We will get the low CET this month deserves, given how rare cold Marches are this one has been quite a shock.

With the North Sea is anomalously cold as it is at the moment hopefully we can avoid winds from an easterly quarter during April, quite a lot of the 12z does unfortunately. Hopefully subsequent runs will see pressure building over the UK instead, at least it's a bit of minor encouragement from GFS.

Edited March 24, 2013 by Quicksilver1989

[nitro_deluxe]

LOL that's alot of straws!! can't see milder returning in a hurry,or until possibly another dumping part deaux for some...

Bit like the last,temps creep up a notch,winds slacken for a time then the LP systems appear,tightening those isobars and boom in comes the colder air again.

Of course,snow cover over alot of the UK is going to help peg down those temps too so no great shakes before then either.

Mad,mad,and i'll say it again mad! if we do get a rinse and repeat type scenario into latter part of the week/Easter weekend!

[mushymanrob]

At least this very cold spell has finally put the nails in the coffin of one myth on here that

gets banded about every February and that is that down here in the south the extra

solar energy makes laying snow much much harder.

Obviously to those of us that have experienced very cold weather in February we know that

to be rubbish but to those that have not well here we are a full month on from late February

with three inches of snow on the ground and icicles hanging from the shed roof that have

not melted or dripped once since first light.

erm, how has it done that? the suns strength DOES make lying snow HARDER to come by.... harder, not impossible!

since 1970 every late snowfall has melted (here) within 24 hours, in winter it would have laid all day. now after 54 hours of snow here, its brightend up, and its rapidly thawing. that would be much more difficult in winter when the suns low and daylength is restricted to 6-7 hours.

i see the gfs 12z has no killer blow to the cold, just a less intense cold for most away from the southwest. the northeast keeps it. personally i dont like this scenario the gfs and ecm has thrown up into april... that of a high pressure anchored just to our north. classic for north sea haar, stratus, dull cold nothingness, as in april 74.

LOL that's alot of straws!! can't see milder returning in a hurry,or until possibly another dumping part deaux for some...

Bit like the last,temps creep up a notch,winds slacken for a time then the LP systems appear,tightening those isobars and boom in comes the colder air again.

Of course,snow cover over alot of the UK is going to help peg down those temps too so no great shakes before then either.

Mad,mad,and i'll say it again mad! if we do get a rinse and repeat type scenario into latter part of the week/Easter weekend!

bib... but if everywhere else is like here, its thawing quite rapidly, despite temps only hovering a degree or two above zero...

[nitro_deluxe]

bib... but if everywhere else is like here, its thawing quite rapidly, despite temps only hovering a degree or two above zero...

Just prior to the latest blizzards/snow event we had some pretty reasonable temps if anything some places were basking in warmth a few days beforehand! this time around,it's far from it so a different kettle of fish or should the next battle commence.You'd need to be a brave person at this stage to draw any lines where rain could be snow or indeed vice versa,come next Thursday and beyond.

[FENDER.]

No thaw here, or anywhere else I have been to today (around the West Midlands)

[Snowman.]

This reminds me of January.

Couple of models wanted to remove the cold after a couple of days over time they altered it and turned it into the even that Wales was issued a red warning.

Could be something similar going through the models at the moment.

No thaw here, or anywhere else I have been to today (around the West Midlands)

Nope secound ice day for most of the UK in march now thats very rare.

[snowking]

GEFS Mean at day 6 very similar to the UKMO this evening:

Certainly a trend towards LP staying to the South, and the UK remaining rather below average temperature wise

SK

Edited March 24, 2013 by snowking

[IanR]

we had blanket of lying snow yesterday morning, nothing now apart from a few clumps here and there where the drifts were, surprised how quick its gone given the air temps, but the sun did come out for 15 minutes this afternnon and did its work at melting the rest of it, i suspect the wind is having a slight thawing effect as well

[Tom Jarvis]

I really feel sorry for Gavin now it is like the tide has changed and instead of looking for the start of a cold spell we are looking for the end which appears in fi only to be crushed by the next set of runs showing bitter easterly all the way through.lol

[Panayiotis]

From Derek on twitter regarding why snow is disappering:

Derek Brockway â€@DerekTheWeather19m

Not much snow will melt this week but some of it will disappear, invisibly, due to SUBLIMATION (solid to gas) with low humidity & dry winds.

Edited March 24, 2013 by Panayiotis

[valiant]

This is why my ice cubes shrivel up in my frost-free freezer. Peer reviewed evidence if ever there was.

[Summer Sun]

GFS full ensemble for London

Good agreement there on no return to the bitter cold we have now a relaxation in the cold looks likely to occur later this week

[AWD]

Not one member brings the 5c Isotherm to the UK;

A stronger cluster reluctant to bring in anything milder at the weekend now too, compared to previous GEFS. Although the stronger cluster still goes above 0c, just, a noticeable cluster do remain below 0c into April now.

A cold set of ensembles for the start of April unfortunetly.

Edited March 24, 2013 by AWD

[Blake]

Raintoday radar in last 4 x 15 min updates showing precip starting to budge south. This should fall in line with what the NAE is showing in regards to wintriness in the home counties tomorrow.

[-uksnow-]

GFS full ensemble for London

Good agreement there on no return to the bitter cold we have now a relaxation in the cold looks likely to occur later this week

Gav, I enjoy your posts but come on look at the spread there and also the number of runs prolonging the cold, as Matt H said, the GFS ens have been playing catch up all winter, this is far for sorted yet as seen by the colder theme brought on by the 12z's so far after this mornings cold wobble - I'm not saying cold will win as I simply don't know at the moment and it's got to end sometime, but there is alot of runs to go before we know the situation of the end of the weeks potential snow event!

All eyes on the ECM about to roll out..

[karlos1983]

GFS full ensemble for London

Good agreement there on no return to the bitter cold we have now a relaxation in the cold looks likely to occur later this week

I don't really see anything resembling Mild in those. Incredible cold given the time of year. Perhaps slightly less cold from roughly the weekend, but even that now has to be a case if more runs needed, Atlantic will break through eventually, but I think it's a while of yet!

[Duane S.]

GFS full ensemble for London

Good agreement there on no return to the bitter cold we have now a relaxation in the cold looks likely to occur later this week

After what seems like at least a month of you posting FI charts / ensembles etc showing a proper warm-up Gav, sooner or later you are going to have to be right! A broken clock and all that... We are now firmly in spring after all so it's only a matter of time!

Continuation of stunning charts (if you like that type of thing, which indeed I do) for late March and the 12zs so far seem pretty keen on some decent trough disruption leading to an undercut and a likely snow event for some come the end of the week. Thereafter, I doubt many have a firm grip on where we head. I certainly wouldn't like to call that one.

Edited March 24, 2013 by s4lancia

[Dave Kightley]

GEFS Mean at day 6 very similar to the UKMO this evening:

Certainly a trend towards LP staying to the South, and the UK remaining rather below average temperature wise

SK

two big dumps on the Channel islands in one month???

[Methuselah]

two big dumps on the Channel islands in one month???

That explains the smell, then?

[Polar Maritime]

That explains the smell, then?

Dirty buggers them lot on the Channel Islands.

Edited March 24, 2013 by Polar Maritime

[SP1986]

We do have to entertain this fact that this cold could be locked in for a long time yet, I would consider May, and whilst that seems unbelievable, this pattern is well and truly locked in, for a while yet. I was wondering if it's possible that Meteorological Spring would not happen this year at all.. and to be honest based on some outputs, this won't be far from the truth.

[NorthNorfolkWeather]

After what seems like at least a month of you posting FI charts / ensembles etc showing a proper warm-up Gav, sooner or later you are going to have to be right! A broken clock and all that... We are now firmly in spring after all so it's only a matter of time!

Continuation of stunning charts (if you like that type of thing, which indeed I do) for late March and the 12zs so far seem pretty keen on some decent trough disruption leading to an undercut and a likely snow event for some come the end of the week. Thereafter, I doubt many have a firm grip on where we head. I certainly wouldn't like to call that one.

I think in all fairness, Gavin was pointing out a relaxation in the intense cold we've had, rather than a wonderful warm spring.

Indeed it does look as though there will be a warm up of sorts, but as Mushy has also pointed out, it's bound to get warmer, the solar influence is much stronger and increasing by the day, the charts have been incredible for the time of year, in some ways glad it wasn't December/January, I would have been cut off for weeks.

As for the next week, mainly dry until the end of the week and the discussion on th etrack of that Low will probably still be going on Thursday

[Tamara]

This is why my ice cubes shrivel up in my frost-free freezer. Peer reviewed evidence if ever there was.

Yes indeed, I have my own experiment in progress

Interesting to see what the ECM does this evening with the low. It was a warm outlier on the operational this morning and the 12z suite thus far much more in line with ensemble expectation.

ECM 12z t96