Spring Model Discussion 25th March 2013 012z onwards

[Chris W]

A personal look ahead to April 4th when I will be flying overseas. I will be a mildie for that day alone as I wouldn't mind my flight from Heathrow taking off on time!

On a less personal note the end of the GFS runs have been hinting at mild for a little while though it has been pushed back repeatedly. If that high sinks SE it could finally be the tipping point to more typical spring conditions but we will see.

[Methuselah]

So, going entirely by today's model-output, we've another good month's crap on the horizon?

[CongletonHeat]

Still frosty though

I can live with cold nights as long as the days have some warmth, possible double figures daytime from that chart and would seem like heaven compared to now.

[nitro_deluxe]

Well it appears that Easterlies are the new westerlies for the UK!

Just a quick question will this very cold weather, affect temperatures in the summer, just the sea around us is alot colder than usual especially for mid spring?! Thanks..

Good point and the answer most definitely must be a yes - what actually happens on the ground is the difficult bit to call or before the milder if not warmer weather finally makes a visit to our shores.Increase in fog/mists/coastal haar perhaps with also some beefy convective activity to boot.

[Yarmy]

I can live with cold nights as long as the days have some warmth, possible double figures daytime from that chart and would seem like heaven compared to now.

Moreover, no biting easterly wind which is the real pain.

[mushymanrob]

Personally I'm enjoying this cold spell but what worries me is when we see a change to the upstream pattern, will it be replaced with a dry and warm high or something far more unsettled which could end up eating away a large chunk of the Summer as well. These patterns over the last few years tend to become blocked for 2-3 months, so any change in the longwave pattern that follows will probably stick around for some time, fingers crossed it's the dry and warm high we see.

couldnt agree more with you (except the first line...lol)... these blocked patterns are hard to shift and this isnt going anywhere fast although it might be less severe. then afterwards i agree that we could get either a dry warm anticyclonic regime or a pretty changable wet one.

So, going entirely by today's model-output, we've another good month's crap on the horizon?

looks that way, im a big believer in patterns because historically synoptic patters tend to last a while, especially these blocked ones. now ive seen what jh interpretation of the anomaly charts suggests and that supports this notion. looks like we are going to experience a poor spring this year after being spoilt in recent years.... oh well...

Edited March 27, 2013 by mushymanrob

[Purga]

Good point and the answer most definitely must be a yes - what actually happens on the ground is the difficult bit to call or before the milder if not warmer weather finally makes a visit to our shores.Increase in fog/mists/coastal haar perhaps with also some beefy convective activity to boot.

I remember after Feb 1986 the sea surface temperatures over the N Sea and Channel got very low circa 2C in parts and there was a long period of misty cold conditions on many occasions even when the synoptics look quite warming.

[Purga]

C'mon Mr NAE - where's all the snow then?

Naff all here at the moment.

Edited March 27, 2013 by Purga

[SomeLikeItHot]

C'mon Mr NAE - where's all the snow then?

Naff all here at the moment.

Saw a forecast this morning that had it snowing in London at 9am, but up above me was the clearest blue sky I've seen in a long long time.

[fergieweather]

C'mon Mr NAE - where's all the snow then?

Naff all here at the moment.

That raw signal is merely testifying to increasing likelihood of flurries/light snow showers as slack upper vortex drifts south. As previously noted, these PPN type charts, irrespective of NWP source, should never be taken at face value without cross-reference to forecast ascents...

[mushymanrob]

C'mon Mr NAE - where's all the snow then?

Naff all here at the moment.

seen some flakes drifting around in the wind... no settling though...

this is now the snowiest march ive ever seen with lying snow for 6 consecutive days and counting... although its pretty clear now, just deeper drifts left.

[fergieweather]

That raw signal is merely testifying to increasing likelihood of flurries/light snow showers as slack upper vortex drifts south. As previously noted, these PPN type charts, irrespective of NWP source, should never be taken at face value without cross-reference to forecast ascents...

Compare with modified version for same timeframe:

[Purga]

That raw signal is merely testifying to increasing likelihood of flurries/light snow showers as slack upper vortex drifts south. As previously noted, these PPN type charts, irrespective of NWP source, should never be taken at face value without cross-reference to forecast ascents...

Thanks for the clarification Ian.

[Rupert Blair]

seen some flakes drifting around in the wind... no settling though...

this is now the snowiest march ive ever seen with lying snow for 6 consecutive days and counting... although its pretty clear now, just deeper drifts left.

Down here in deepest Sussex there still some little bits of drift left from 16-17 days ago.. Not much now though

[Mark Neal.]

Compare with modified version for same timeframe:

That modified version is much more comparable to the current radar, snow flurries around here. But not as extensive as the NAE was going for!

[Summer Sun]

Still frosty though

Mild by day though

[offerman]

Mark,Reply to your earlier post about cold sea, well this could lead to more extremes if we get some hot weather as more differentials between the heat of the land and cold sea. AIMHO i`m no expert and could be wrong but that's my take.

I know a warmer sea also can mean more energy and bigger storms but also greater temp differentials can play a key part to.

[Captain Shortwave]

Mild by day though

Urgh even the Yarmouth/Lowestoft/Beccles triangle exists for warmer temperatures too. These models hate this area of the country

[weather_it_will]

C'mon Mr NAE - where's all the snow then?

Naff all here at the moment.

Been snowing here all day on and off in Birmingham area.

Edited March 27, 2013 by Deep Freeze

[Iceni]

Down here in deepest Sussex there still some little bits of drift left from 16-17 days ago.. Not much now though

In west Suffolk we still have some drifts left along the n/e or e hedgerows and the wind is still bitingly cold. We've kept our Christmas decorations of icicles along the thatch — even on the south side of the house, the wind's keeping them cold.

[Summer Sun]

The ECM Birmingham ensemble continues its slow but steady rise in temperatures from Monday

The average ranges from 6c on Easter Monday to 9c by April 9th & 10th the average for the time of year is 12 to 13c

From Easter Monday the average low ranges from -1c to +3c the average for the time of year is 4c

Precipitation is below or on average right through to April 9th

Edited March 27, 2013 by Gavin.

[swilliam]

Mild by day though

Thats average not mild (nice in the sun though if we manage to get any. Edited March 27, 2013 by swilliam

[Purga]

Down here in deepest Sussex there still some little bits of drift left from 16-17 days ago.. Not much now though

Yes - noticed some of that old snow at Turners Hill left by the side of the B2110 to East Grinstead the other day. Anyway should be in the regionals I guess.

The 06z ENS showing a split with some runs still going for -10C uppers right out to 11th April.

Just need the precipitation to coincide.

Edited March 27, 2013 by Purga

[phil nw.]

It could be well into April before we see daytime temps.exceeding 10c widely going by the various 00z Ens. outputs.

The 3 images below are the NAEF`s and ECM 500hPa anomalies alongside the mean 850hPa temps.

all for day 10.

As can be seen still the same overall upper air pattern-High pressure to our north and low pressure to our south.

The PFJ still on a southerly track taking much of the unsettled conditions through France and areas in S.Europe.Nothing to drive our resident cold pool away at this stage,just a very gradual easing of the coldest air with the increase in solar output as we go further into April.The mean 850`s still showing the UK very much in colder air at day10.

Weatherwise looking at the 2m and precip. graphs for London it looks like a largely dry and cold period through Easter and beyond at this stage with an ongoing risk of night frosts.

We can`t rule out one of those systems just to our south encroaching further north but at this stage the blocking high is modeled to be the dominating feature for the UK keeping things fairly settled.

http://www.meteociel...1-168.GIF?27-12

Again the 2m graph shows those surface temps remaining in single figures for the foreseeable so let`s hope at least we see some sunny spells to brighten things up whilst we continue to wait for a proper warm up.

[Summer Sun]

A look at summer curtsey of CFS

Uppers

June

July

August

Average pressure for the same time

June

July

August

And the 2m temperatures

June

July

August

PS these CFS charts got this cold spell in advance so its going to be a case of seeing what it shows over the coming weeks

If I understand the 2m temperature correctly that would bring average temperatures in the high teens?

A look at the remainder of spring can be found here - http://forum.netweat...80#entry2667888

Edited March 27, 2013 by Gavin.