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

[Dennis]

GEM model - more signs of a Greenland setup possible

Edited February 15, 2017 by Dennis

[knocker]

Once more the anomalies are in good agreement and showing no significant change from recent runs.

In the 6-10 period still the quite complex vortex with the main lobe beginning the switch to N.Canada/Greenland from NE Europe accompanied by the retrogression of the ridge to the GOA. With the trough in the NW Atlantic and still positive anomalies with some ridging in the eastern Atlantic we are still looking at an upper flow from a westerly qudrant and thus in general terms still a N/S split in the UK with the south remaining predominately dry and the temps around average or above.This doesn't rule out transient Pm incursions. Of course the det runs will sort the details but, IMO, it's always worth remembering that the fluid (phasing) interaction of the cold and warm airmasses over the Atlantic is always going to be subject to day to day variations and timing differences with the models so a one model scenario in this time frame should be treated with caution.

No significant change in the later time frame with the main lobe now over Canada/Greenland and a pretty zonal Atlantic.Ergo remaing unsettled temps around average

Edited February 15, 2017 by knocker

[snowbunting]

Liking the fact that both ECM and GFS are suggesting some form of a Nly around the 22nd /23rd of the Month. I get a feeling that the GFS is playing up the atlantic again.

What comes of this warming of the stratosphere, awaits to be seen, A repeat performance of 2006 surely cannot be ruled out?

 

[cheeky_monkey]

2 minutes ago, snowbunting said:

Liking the fact that both ECM and GFS are suggesting some form of a Nly around the 22nd /23rd of the Month. I get a feeling that the GFS is playing up the atlantic again.

What comes of this warming of the stratosphere, awaits to be seen, A repeat performance of 2006 surely cannot be ruled out?

 

What Happened in 2006 exactly??

[karyo]

4 minutes ago, cheeky_monkey said:

What Happened in 2006 exactly??

March 2006 was a wintry paradise!

[snowbunting]

3 minutes ago, karyo said:

March 2006 was a wintry paradise!

Just a Tad, 17 days of snow falling, winter refused to go away, it was after a pretty disappointing winter 05/06.

[Fourty Point Three Degrees]

Some unusually warm daytimes to look forward to in the upcoming days. Should feel rather pleasant in any sunshine, I wont be surprised if we can touch the first 20c of the year before the month is out.

[jethro]

3 minutes ago, 40*C said:

Some unusually warm daytimes to look forward to in the upcoming days. Should feel rather pleasant in any sunshine, I wont be surprised if we can touch the first 20c of the year before the month is out.

Seriously? I'd be shocked and stunned.

[March]

It's unlikely but the record for the first 20C is early March so with climate change I wouldn't rule out a Feb foehn effect 20C in the near future.

[knocker]

This morning's GEFS is much as expected with the changes upstream and the Canadian vortex becoming more influential. Thus a continuation of the westerly upper  flow across the Atlantic and the fluid interaction of the warm and cold air. The det will determine the detail in the ten day time span, or thereabouts.

Once the low tracking across N. Scotland today is out of the way we have high pressure building from the south west and with the cell to the south slipping south east this initiates a warm WNW flow over the UK and by midday on Sunday the situation is thus.

This persists until Tuesday, giving temps in 14C-16C region on Monday before the aforementioned interaction pushes the high Pressure SW. This veers the wind and introduces cooler air from the NW over the UK and returning the temp to around average or a little below for a short time.

From this position the depression that can be seen on the chart above 986mb in the western Atlantic, deepens and tracks NE south of Iceland, and then east bringing some unsettled and windy conditions to the end of the week. In a nutshell much what one would expect.

Edited February 16, 2017 by knocker

[knocker]

Although differing on detail the ecm singing from the same song sheet. Temps of 14C quite widespread on Monday so certainly 16C can't be ruled out in some spots.

Edited February 16, 2017 by knocker

[Stephen W]

From my untrained eye, there does not seem to be much evidence of a displaced SPV appearing within the exetended modelling at the moment.  If anything, it seems pretty much in situ with lots of energy being expelled at higher latitudes. The Azores high seems very prevalent, waiting in the wings to throw up a warm ridge and only occasionally pulling back to allow a short sharp burst from the NW.  The ECM has a familiar MLB setting up over Europe at the far reaches but there is too much energy north to allow any higher level blocking. This MLB serves to discharge any potential cold south with most of the UK kept on the warm side with a sw fetch. At least there is some movement after this weekend to something different from mid next week. It's still February and I'd like to be in winter. Spring can wait til March..

[phil nw.]

A mild and fairly benign week looks on the cards for most as this rather unintersting season ebbs away.

Later modeling continues to show a short colder polar maritime spell as we enter the last week of Winter.Scotland could see snow from that but areas further south would need something colder than currently shown to see anything wintry.

Edited February 16, 2017 by phil nw.

[Frosty.]

An early taste of spring is on the way with temps into the low to mid teens celsius across southern uk. The Gfs 00z looks very pleasant for a time next week but we then flip back to winter later in the week with snow showers to exposed northern and eastern coastal parts and widespread frosts for a time before it starts turning milder again. The run ends with a lovely anticyclone centred over the uk. 

Edited February 16, 2017 by Frosty.

[Seasonality]

ECM 00z still going a for a little pulse of cooler air. Chillier 850s into Europe later on in the run too. Just for fun at this range though, and to be honest I'm not particularly interested in some half-baked attempt at cold weather this late in the season. 

[Seasonality]

2 minutes ago, Frosty. said:

An early taste of spring is on the way with temps into the low to mid teens celsius across southern uk. The Gfs 00z looks very pleasant for a time next week but we then flip back to winter later in the week with snow showers to exposed northern and eastern coastal parts and widespread frosts for a time before it starts turning milder again. The run ends with a lovely anticyclone centred over the uk. 

There'd be some good diurnal variation at that time of the year too if it is a sunny high. I love Spring days when it starts off frosty then rapidly warms up in the bright sunshine.

[jvenge]

12 minutes ago, Seasonality said:

ECM 00z still going a for a little pulse of cooler air. Chillier 850s into Europe later on in the run too. Just for fun at this range though, and to be honest I'm not particularly interested in some half-baked attempt at cold weather this late in the season. 

Yes, although some are craving a cold shot, the cold air on offer isn't potent enough to deliver something interesting. Winter or Spring. Not something in between. At least that's my preference anyway :-)

Colder air that the GFS is trying to promote over the black sea in the latter stages of the run is also not supported by the ensembles, thankfully. I think we will see the GFS trending milder as the runs keep coming and what you see from day 8 at the moment will firm up into even milder and a prolonged taste of Spring.

For those looking for a cold end to the month or a cold start to March, it isn't looking overly likely at all and the form horse is a nice Spring like end to Winter.

 

Edited February 16, 2017 by jvenge

[Frosty.]

7 minutes ago, Seasonality said:

 I love Spring days when it starts off frosty then rapidly warms up in the bright sunshine.

Me too, the end of the Gfs 00z is a peach

 

[bluearmy]

The ecm strat charts continue to show an area of strongish zonal flow being flushed down by the reversal higher up. around 50/70N 300/500hpa which would make any thoughts of anything other than fleeting HLB end of week 2 seem fanciful. still concerns that a chilly march could be on the horizon and that would be the worse case scenario for the southern half uk. . V slim chances that we see proper snowfall in march away from elevation or the north. 

[jvenge]

The cold shot shown on the GFS on the 24th would be unlikely to bring anything of interest, even to those in the north. After that, it is a swift return to mild.

 

[Summer Sun]

GFS ens comparison between Tuesday and today

14th

16th

 

[TEITS]

1 hour ago, bluearmy said:

The ecm strat charts continue to show an area of strongish zonal flow being flushed down by the reversal higher up. around 50/70N 300/500hpa which would make any thoughts of anything other than fleeting HLB end of week 2 seem fanciful. still concerns that a chilly march could be on the horizon and that would be the worse case scenario for the southern half uk. . V slim chances that we see proper snowfall in march away from elevation or the north. 

Have to be honest nothing in the model output suggests anything exciting except a weak, shortlived N,ly at the moment. I do disagree with your last sentence. A decent snowfall in March away from the areas you mention might be uncommon during the daylight hrs. However what is perfectly possible for low lying areas in the S is a decent snowfall during the night. You do however need to be up early taking your pics before the sun starts thawing the lying snow.

[Matthew.]

A brief colder northerly interlude end of next week on the GFS 6z

[Nick F]

Spring on Monday, with mid-teens over Midlands and E England

... to winter next Friday, as a N/NWly flow brings temps struggling to get higher than low single figures Midlands north.

00z EPS z500 mean indicating support for the brief N-NWly end of next week, as upper flow amplification moves out of NE N America downstream over N Atlantic.

Unfortunately, good agreement, the flow switches back to SWly thereafter, as a trough digs SE from N Canada out into the NW Atlantic

[nick sussex]

Looks like the other models are slowly edging towards the ECM solution with splitting that shortwave energy upstream, originally they kept a train of that stopping the displacement of the Azores high to the nw.

At the moment its not looking like any cold will last very long however the ECM at day ten upstream doesn't look bad, its likely the PV to the north will get pulled further to the nw as it engages that troughing over central Canada, it really depends how much dig we see upstream of the troughing over Greenland extending south as to whether we see a stronger ridge thrown ne ahead of that.

Not outside the bounds of possibilities that the ridge won't develop further north around this time.

The thought of another easterly isn't really filling me with much joy however and at this time of year a ne/n flow is generally better for cold unless a lobe of the PV is under the block to the east to feed deeper cold westwards.