Model output discussion 25th Jan - The final third of winter beckons..

[snowray]

Well well well, what do we have here now..

[Richard Fisher]

1 minute ago, snowray said:

Well well well, what do we have here now..

Rain/sleet

[nick sussex]

5 minutes ago, Doctor96 said:

If we end up with rain or just sleet on the east coast , this will go down as such a let down and an over hyped dreadful easterly. I hope this is not the case , but what a change from the two weeks severe cold that i and others thought was coming.

 

But lets hoep late Feb is better before we run out of time for winter

I'm not sure where this severe cold was forecast? Theres  opportunities for cold and snow during the next few weeks but the easterly doesn't have a lobe of the PV underneath it to provide that depth of cold. Unfortunately easterlies seem to get expectations that are rarely met, it would be great to see one of those 5 star ones again but we are where we are. In the context of UK winters 4 to 5 days below average with some snow and frost is quite a success and there maybe better to come later after that less cold interlude.

[NorthYorksWeather]

7 minutes ago, snowray said:

Well well well, what do we have here now..

Looks like a trough moving in from the North Sea which you can see on the GFS precip charts. Looking at the available data  it seems that it may fall as rain/sleet to coast and lower levels but inland and certainly with elevation there may be some decent snowfall. 

[snowray]

Seems to stay mainly as rain/sleet in the east after all, latest Euro 4 has surprised me, thought it would have been all snow by this Thursday, look at them uppers.

 

[snowray]

Even the North Sea is normally full of snow when uppers are at or above -10c and DP below 0, I mean that warm front is not due until Saturday. 

All very strange indeed.

[TEITS]

22 minutes ago, Doctor96 said:

If we end up with rain or just sleet on the east coast , this will go down as such a let down and an over hyped dreadful easterly. I hope this is not the case , but what a change from the two weeks severe cold that i and others thought was coming. 

 

But lets hoep late Feb is better before we run out of time for winter 

If you don't mind me saying I don't recall a single model run that indicated severe cold. Throughout the modelling the lowest upper temps have always been around -10 to -11C. Only a few rogue runs like the GEM projected anything lower. For a severe cold spell in Feb from the E then you are looking at upper temps at -15C or below.

This is a severe cold, snowy E,ly. For my location this was better than Jan 87 for snowfall amounts!

 

[sorepaw1]

I'm staying optimistic past T+144 hrs in all my 30 plus years of study Easterly winds have been a nightmare to forecast once there upon us imo.

I'd say sit back and wait a few days as we enter the middle of the polar continental air and see where we are on Sundays 12z up to T+120hrs if we see a trend to milder southerly air flow so be it. That's the way it goes but I aren't  convinced that this is just a 5 day cold snap... but I'm open to be wrong and constructive feedback. 

Edited February 8, 2017 by sorepaw1
Spelling

[Cheshire Freeze]

11 minutes ago, TEITS said:

If you don't mind me saying I don't recall a single model run that indicated severe cold. Throughout the modelling the lowest upper temps have always been around -10 to -11C. Only a few rogue runs like the GEM projected anything lower. For a severe cold spell in Feb from the E then you are looking at upper temps at -15C or below.

This is a severe cold, snowy E,ly. For my location this was better than Jan 87 for snowfall amounts!

 

Perfect wedge of heights, perfect trough distribution across mainland Europe- its spatial distribution meaning no warm air intrusion from further SE, LP at eastern side helping to spin cold air round the block like a conveyor...yep, don't make 'em like that anymore!

Edited February 8, 2017 by CreweCold

[Duane S.]

Just to attempt to bring a sense of reality back to this thread to all those who appear unable to control their emotions because we aren't going to get a Beast From The East style Easterly.

Despite what an alien may think if they had just arrived from outer space and started reading the last few pages of this forum, I am sorry to burst some bubbles but a 'proper' snowy Easterly was NEVER actually forecast by anybody of any standing here simply because, other than a few wayward Op runs, it never showed up on the charts. It was ALWAYS an outside chance and so it proved to be correct. It would appear that some exuberance and excitement exhibited by those of us who actually enjoy the chase when there is a genuine opportunity of a snowy spell has been mistaken for some sort of set in stone 100% forecast. Nope we were just getting excited by the possibility of. some people evidently need to be able to distinguish between the two.

Our alien will now read this post and will no doubt think there is no cold spell at all arriving! So imagine his confusion when the next thing he does is go on to view the charts. Why? because we do have an Easterly on the way and a half decent one at that as well. He would then be no doubt further perplexed as he scrawled through the charts trying to find this searing plume sourced from the scorched deserts of Africa that many speak of...

Of course we are all a bit disappointed that the easterly does not look like being as good as it could have do but conversely it could have not verified at all (most don't make it over all the hurdles and through all the hoops required to get to a winter Easterly). Let's see what occurs instead of writing it off before it is even here FGS.

So much left to happen yet, best model watching for a long time.

[Thundery wintry showers]

2 hours ago, summer blizzard said:

Dew points are higher on Saturday because of precipitation. Think back to Feb 05 and 06 and 09 when the fronts came from the east (clearly this is less organised) and we'll probably see similar. The east and south east struggled while inland we were fine. 

It did snow and settle up at 185m on those occasions, but I recall that low lying areas struggled generally.  I was in central Leeds in the February 2006 event and although it was preceded and followed by snow showers, the frontal system fell as rain. Particularly in the February 2009 case, though, many inland areas already had a significant snow cover from preceding snow showers and the frontal belt of sleet or wet snow didn't make much of a dent on the snow cover.  Also, in those cases dew points were generally between 0 and 1C, rather than 2C as is currently forecast for many areas for Saturday afternoon.

In my experience a good rule of thumb (with certain exceptions, e.g. bright showery days in spring with a shallow warm layer near the surface) is that for snow, the wet bulb temperature (or the average of the dry bulb and dew point, which is a close approximation) needs to be less than a degree above zero.  Many of the classic "heavy wet sticky snow with big snowflakes" type events have seen dew points just above freezing, but I can't recall any with dew points between 1 and 2C.

That said, I think many eastern areas could well see a covering to low levels on Friday and also early on Saturday, and Saturday could well see a spell of snow for many areas on the western flank of the frontal systems.  The weak nature of the systems won't help matters though; often in these marginal setups heavy precipitation makes the difference between rain/sleet and snow due to evaporative cooling.

Edited February 8, 2017 by Thundery wintry showers

[East_England_Stormchaser91]

Saturday evening looking very good or much of the country! 

Watching this space very carefully. Height rises are looking much better over Iceland and towards Greenland on this 00z run. Looks to be better retrogression. 

Edited February 8, 2017 by East_England_Stormchaser91

[Connor Bailey Degnan]

Well, cross model agreement on it Turning much milder next week, what an awful winter it has been for the Met. 

Anyway, in the short term, some good news, a 4-5 day cold spell. Some snow around, areas prone, Eastern Scotland and North East England, although many places could see something come Saturday and Sunday.  Some moderation from the north sea may spoil the party nearer to the coast.

Enjoy the cold

[jvenge]

Mild spell still 7-8 days away. I need not tell most people here what can happen at that range.

However, the mean temperature from the GEFS is creeping up each run and into FI it is now an early taste of Spring.

[mb018538]

1 hour ago, jvenge said:

Mild spell still 7-8 days away. I need not tell most people here what can happen at that range.

However, the mean temperature from the GEFS is creeping up each run and into FI it is now an early taste of Spring.

With 19/20 members going mild, I think we can say with some confidence that it's going to happen now. For some reason people keep slagging off the ECM run, but it was clearly first in picking this new trend out a few days back! The colder FI runs of a couple of days ago have all but disappeared from the ensembles too. By the time that rolls around we will be rapidly approaching March, and time will be really running out. Yes, I know we can still get cold and snow in March, but it needs to pack a lot more of a punch to have an effect. 

Edited February 8, 2017 by Paul

[Jimmyh]

35 minutes ago, Connor Bailey Degnan said:

Well, cross model agreement on it Turning much milder next week, what an awful winter it has been for the Met. 

Anyway, in the short term, some good news, a 4-5 day cold spell. Some snow around, areas prone, Eastern Scotland and North East England, although many places could see something come Saturday and Sunday.  Some moderation from the north sea may spoil the party nearer to the coast.

Enjoy the cold

Sorry why on earth are you having a go at the met????? Not one single experienced poster has had anything bad to say about the met they have nailed it more times than the gfs and ecm. They have called it correct more times than not.

 

[Ali1977]

Well the GFS and GEFS are shocking for coldies beyond the weekend, I can't even pick a positive point out!!

ECM running, is it time for this model to show some better looking coldie charts I wonder!!! Tick tock tick tock as winter goes by!!

Edited February 8, 2017 by Ali1977

[NorthYorksWeather]

Conditions look better for snowfall more widely on Saturday and not just high ground on this mornings GFS.

The possible event is still 90 hrs away so I'm sure there's more twists and turns to come.

Here's a few charts from the 00z

According to the GFS at the time of the precip arrving on Sat IMBY there will be uppers 850s of -7c, dew point at 0c and 0c isotherm between 300-400m.

That would suggest a good chance of snow falling. Car at the ready in case it ends up being a 400m+ event.

[mb018538]

ECM joins GFS in bringing the warmer temps by the middle of next week:



850s over 5c....should feel very nice if it verifies

[NorthYorksWeather]

Just now, mb018538 said:

ECM joins GFS in bringing the warmer temps by the middle of next week:



850s over 5c....should feel very nice if it verifies

Indeed! What is it with this bloody Euro high this winter?

A look at the NH view at day 8 shows ECM trying its hardest for high pressure towards Iceland/Greenland but the Euro high is laughing at it saying "you call that a high mate?".

[East_England_Stormchaser91]

I'm not trying to speak against the facts about what the models are showing. However, I wouldn't be surprised with a different scenario showing its hands after the weekend. Still plenty of time for corrections and alterations that could easily place us in the firing line for a reload. One very tiny difference could occur within the orientation of these southerly winds. If we end up with a less intense low towards Iberia and it doesn't sink adjacent to Morocco, then there's no route for the African heights and winds to be scooped up. Not only that, the high pressure could well end up orientated differently and allow a less SEly component and more cold flooding into the Balkans. That would then leave us God knows where. 

A very interesting model watching period coming up I feel. 

Edited February 8, 2017 by East_England_Stormchaser91

[mb018538]

ECM ends flat and mild. Trend or outlier, that is the question. Either way, doesn't look too sharp this morning.

It appears that Thu/Fri/Sat/Sun are the 4 days that this cold snap will encompass, before things start changing over Monday into Tuesday. Whether it ends up just remaining chilly from a continental feeds, or warmer with a plume of air from North Africa, will be the devil in the detail over the coming days.

[Johnp]

There's no dressing it up I'm afraid this morning - absolutely dire models this morning if it's cold you're after (post the weekend).

 

[Lampostwatcher]

gfs upgrade for snow on saturday

[East_England_Stormchaser91]

7 minutes ago, Johnp said:

There's no dressing it up I'm afraid this morning - absolutely dire models this morning if it's cold you're after (post the weekend).

 

There's the GFS, there's the ECM, there's the UKMO, GEM, JMA.. And then there's the weather. Let's see how the next 72 hours roll out and let's watch carefully how our heights to the NW behave, seen as they are progged to do a loop the loop around the UK, we'll see about that. 

Edited February 8, 2017 by East_England_Stormchaser91