Model output discussion 8th Feb - Cold for now, but then what?

[knocker]

The low pressure to our east wanders around in the northern N. Sea for a couple of days before the next complex upper trough arrives at the weekend with a couple of surface lows, the first of which arrives west of Cornwall Saturday 00. These will bring rain to the south and perhaps some snow on the hills further north

This heralds a surge of the high pressure to the east and the accompanying deconstruction of the trough and initiating the Azores high pressure to do likewise with the jet doing a rapid right turn into North Africa.

Thus for the rest of the week the influence of both the HP systems is paramount and the UK is a bit of a battle zone as the Atlantic struggles to make inroads so a N.S split is very much on the cards until the breakthrough at the end of the week. So essentially we are looking at a very mixed bag with temps around average but trending above next week.

Looking further ahead we may still be looking at amplification in the Atlantic with the upper flow in the NW and the troughs running SE further west.

Edited March 1, 2017 by knocker

[NO LONGER POSTING]

When do you finally call it quits on cold weather? We are now in March and although statistically March is still fairly cold it's rare to have proper cold. The same speaks for April. 

The issue is cold late March early April can be devastating for farmers, nature and animals. Every year we have the same issue where we chase chase chase cold and then spring trys to kick in. 

The models don't really have much cold on them this morning (certainly the gfs anyway) but where do we draw a line in the sand and say enough cold now, time for spring warmth and get things in gear? 

 

[knocker]

13 minutes ago, Surrey said:

When do you finally call it quits on cold weather? We are now in March and although statistically March is still fairly cold it's rare to have proper cold. The same speaks for April. 

The issue is cold late March early April can be devastating for farmers, nature and animals. Every year we have the same issue where we chase chase chase cold and then spring trys to kick in. 

The models don't really have much cold on them this morning (certainly the gfs anyway) but where do we draw a line in the sand and say enough cold now, time for spring warmth and get things in gear? 

 

Early December?

[mb018538]

The ECM turns on the warmth in the latter half of this morning run:







Upper teens in the south by 216 hours. No cold weather on offer on this mornings extended runs. At 144 it looks at though the continental feed might hang on, but is soon shoved out of the way.

[knocker]

Although of course varying i detail the ecm does a passable imitation of the gfs. Perhaps temps up around 14C again next week.

[mb018538]

It certainly does. Where does that leave us in terms of winter? With what looks like probably the first half of March now unlikely to deliver anything, is that it for Winter 16/17? It'll take one heck of a blast to get us anything decent in the second half of the month.

[Frosty.]

Well it's the first day of the meteorological spring and the Ecm 00z gives us a brief taste of warm spring days to come with this little beauty!

[jvenge]

GEFS 0Z are not quite as good as the 18z when it comes to the depth of the cold on offer out into FI. Still, a few are showing a good chance of something interesting, but the uppers would be a concern and one wonders just how low those temperatures can get on the ground with what's on offer. We are far from ice day territory. Something to watch, though.

[Frosty.]

The Gem 00z builds high pressure into the uk later in the run with some pleasant early spring conditions.

[Summer Sun]

Wouldn't last too long with the low out west waiting in the wings but maybe the upper teens for the south?

[Man With Beard]

Some SW versus NE battles coming up for D5/D6 and ECM this morning shows what would happen if a decisive win for the SW occurs - Hello Spring for southern/eastern areas:

The type of early March chart that would push towards the 20C mark. #bbq

[jvenge]

Hmm, not sure on that, maybe to 15 or so in some parts? I can't see ECM surface temperatures, but it is hard to imagine close to 20 based on the above 850.  Most 12-14, I'd say. I think what it would give is relatively mild nights though, with night time temperatures of 10 degrees or so.

[Man With Beard]

3 minutes ago, jvenge said:

Hmm, not sure on that, maybe to 15 or so in some parts? I can't see ECM surface temperatures, but it is hard to imagine close to 20 based on the above 850.  Most 12-14, I'd say. I think what it would give is relatively mild nights though, with night time temperatures of 10 degrees or so.

This chart produced 21C at exactly the same time of year - not too different as far as the UK is concerned.

uppers were a little higher but not much

[Frosty.]

29 minutes ago, Summer Sun said:

Wouldn't last too long with the low out west waiting in the wings but maybe the upper teens for the south?

It's the kind of chart I look forward to in summer, ideally with the low further to the southwest to improve longevity and heat intensity but temps would still briefly soar into the 80's F with the chart above in the summer months..hope we are in for a good one!

Edited March 1, 2017 by Frosty.

[knocker]

The ext EPS this morning shows a diffuse and weakening vortex over the Pole, positive anomalies and some ridging to the west of the UK and a trough to the east running south to the Mediterranean. Ergo an upper flow tending NW and a possibility of interludes of more 'wintry' weather as systems traverse south east. Temps generally a little below normal.

[Man With Beard]

I shall carry on the conversation with myself. Just a few days later (D12/D13), both GEFS and ECM means have heights pushing into the North Atlantic:

  

Obviously a number of ways that the low/high pressure systems may interact in such a circumstance, but one to watch as it may provide winter 2016/17 with one last (first?!!) hurrah if the pressure set up resembles the GEFS mean in any way - could it lead to the first genuine northerly of the season?

Just a reminder that the latest NOAA was clearly open to the suggestion too

Edited March 1, 2017 by Man With Beard

[Frosty.]

There is tons of Arctic potential on the GEFS 6z in both the mid and longer range, more than I've seen for a while and reading between the lines of the latest MO update doesn't indicate any downgrade to me regarding the possibility of cold spells with a risk of snow during the weeks ahead..all to play for.

Edited March 1, 2017 by Frosty.

[Methuselah]

Well Frosty, as much as I love your unbridled enthusiasm, there's been 'tons of Arctic potential' ever since the end of November? Gimme some plume potential, eh?

[Frosty.]

6 minutes ago, Ed Stone said:

Well Frosty, as much as I love your unbridled enthusiasm, there's been 'tons of Arctic potential' ever since the end of November? Gimme some plume potential, eh?

That's what I love about March / April Ed, you can get an early plume and a freeze. There are a lot of cold 6z perturbations today, something particularly wintry may be on the way for mid / late March.

[Methuselah]

7 minutes ago, Frosty. said:

That's what I love about March / April Ed, you can get an early plume and a freeze. There are a lot of cold 6z perturbations today, something particularly wintry may be on the way for mid / late March.

I love lying snow in January - it brightens everything up and relieves my SAD - but, come March and April, it's a pain in the bum!

[Frosty.]

Just now, Ed Stone said:

I love lying snow in January - it brightens everything up and relieves my SAD - but, come March and April, it's a pain in the bum!

I'm happy if we get an early plume / warm spell from now on or a potent Arctic blast so it's win win for me..anyway, interesting model output with something for everyone.

[johnholmes]

3 hours ago, Man With Beard said:

I shall carry on the conversation with myself. Just a few days later (D12/D13), both GEFS and ECM means have heights pushing into the North Atlantic:

  

Obviously a number of ways that the low/high pressure systems may interact in such a circumstance, but one to watch as it may provide winter 2016/17 with one last (first?!!) hurrah if the pressure set up resembles the GEFS mean in any way - could it lead to the first genuine northerly of the season?

Just a reminder that the latest NOAA was clearly open to the suggestion too

I'm not at all clear how that NOAA chart suggests a northerly?

[Fourty Point Three Degrees]

I wouldn't count on any cold spell delivering the full fruit you'd expect to see mid-January. The sun is far too strong and too near to our side of the equator.

[MP-R]

7 hours ago, Surrey said:

When do you finally call it quits on cold weather? We are now in March and although statistically March is still fairly cold it's rare to have proper cold. The same speaks for April. 

The issue is cold late March early April can be devastating for farmers, nature and animals. Every year we have the same issue where we chase chase chase cold and then spring trys to kick in. 

 

Quite right! Personally, I tend to still look for cold spells until March 21st, don't look for prolonged hot spells until after June 21st, don't look for signs of autumn until September 21st, and don't look for prolonged cold until December 21st. Generally speaking this way of thinking hasn't failed me too many times. Of course there are exceptions e.g. March/April 2013; first half of June 2006; September 2008, 2011 and 2015; and December 2010. Needless to say, expectations will vary countrywide.

Back to the here and now. GFS looks very mobile at least until the 09th/10th (nothing unusual there) when real uncertainty starts for me. We get very close to a mild anticyclonic spell and a few days later very close to a cold northerly. This weekend in particular looks quite wet with a low crossing the southern half of the country.

ECM is boardly similar, making more of a warm interlude on the 09th/10th before a return of the Atlantic on its last slide.

GEM  and UKMO also singing similarly but with more emphasis no rain, especially across the south between the 04th and 06th.

All in all, unsettled and changeable and often quite windy. Indeed, a week on from Doris, my location is looking at wind gusts in the 50-60MPH region again tomorrow.

 

[Rollo]

1 hour ago, MP-R said:

Quite right! Personally, I tend to still look for cold spells until March 21st, don't look for prolonged hot spells until after June 21st, don't look for signs of autumn until September 21st, and don't look for prolonged cold until December 21st. Generally speaking this way of thinking hasn't failed me too many times. Of course there are exceptions e.g. March/April 2013; first half of June 2006; September 2008, 2011 and 2015; and December 2010. Needless to say, expectations will vary countrywide.

Back to the here and now. GFS looks very mobile at least until the 09th/10th (nothing unusual there) when real uncertainty starts for me. We get very close to a mild anticyclonic spell and a few days later very close to a cold northerly. This weekend in particular looks quite wet with a low crossing the southern half of the country.

ECM is boardly similar, making more of a warm interlude on the 09th/10th before a return of the Atlantic on its last slide.

GEM  and UKMO also singing similarly but with more emphasis no rain, especially across the south between the 04th and 06th.

All in all, unsettled and changeable and often quite windy. Indeed, a week on from Doris, my location is looking at wind gusts in the 50-60MPH region again tomorrow.

 

Quite right afer March 21st even the the best snowfalls that just might occur  melt pretty quickly here up till then there is an outside chance that it may last a couple of days,given that this winter we have had about half a day of lying snow the chances appear pretty slim.