All academic at this range, but ECM is a) more severe, but b) much more amplified upstream. 

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What those verifications positions don’t tell you are what each model is good or better doing than the other in different weather situations.

So we cant rule one is right over the others at any one particular time.

I don’t think any weather freak knows them all each model has better points.

For example gfs over the years has been good at picking out uk northerlies and new trends but it reluctance to undercut and its bombs have often been a joke.

Ecm tends imo only to overdo n/h blocking and east west bias but it’s finer detail often has it winning out.

Hence a safer bet is often the used word blended solution.

Looks to me like a more potent version of what happened in mid-January last year.

Were things to verify like that, I think it would quite likely bring a fair dumping of snow to some areas, especially in the north.

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Drop of almost 50mb off the NW coast of Scotland in just 24hrs. 

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That scenario has popped up once or twice on the GFS output and is worth watching. Some wintry potential in the output currently and some very interesting charts around. 

CP, is the terminology a “snow bomb”? 

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A real bomb that goes almost goes due south from Iceland. You can tell something's afoot!

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Best run for a while Para esque in its extremeness

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Even if the ecm 240 verified it would require northern blocking to persist to take advantage of the low diving SE, which is a classic gateway to a cold spell, but only if the situation is capitalized on by subsequent northern blocking. Interesting from an academic perspective only at this large distance across fantasy island.

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Oddly, but predictably, no real widespread high wind speeds on the ECM forecast, except of course, for those Scottish islands. 

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Hi all,

Just a quick observation. The main differences in the ensemble members as to whether they turn cold(er), earlier, seems to me to relate to the pace of the strange elongated low coming up the eastern half of the US next weekend. The GFSP has it slightly slower but also takes the system on a slightly different but crucial track.

The first set are for next Sunday 1200. Showing the 850s and the huge temperature contrasts.

OP 144 850s
http://www.wetterzentrale.de/de/topkarten.php?map=5&model=gfs&var=2&time=144&run=12&lid=OP&h=0&mv=0&tr=3 

PARA 144 850s
http://www.wetterzentrale.de/de/topkarten.php?map=5&model=gfs&var=2&time=144&run=12&lid=PARA&h=0&tr=3&mv=0 

The next set 24 hours later, show SLP. The Para deepens the storm and sends it on a more northerly and ultimately slower track. The differences in phasing, I think, are crucial with how the pattern plays out downstream and therefore how early the colder (enough for more widespread snow) temps arrive in the UK.

OP 168 SLP
http://www.wetterzentrale.de/de/topkarten.php?map=5&model=gfs&var=1&time=168&run=12&lid=OP&h=0&tr=3&mv=0 

PARA 168 SLP
http://www.wetterzentrale.de/de/topkarten.php?map=5&model=gfs&var=1&time=168&run=12&lid=PARA&h=0&tr=3&mv=0 

If someone would be kind enough to paste the images (I cant seem todo that on the IPad!), then great.

As the week progresses, it might be good to keep in touch with the guys at Accuweather. My sense is the Para has this nailed more closely. These Eastern Seabaord lows generally deepen much more with these temperature contrasts which in turn tends to see them curve more northward.

https://www.accuweather.com/en/weather-news/snowstorms-to-deliver-one-two-punch-to-midwest-and-northeast-this-week/70007144 

Thoughts?

Jeff

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Not sure about that, but you would be favoured than most for something a bit more seasonal from this run! 

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That T+216 chart would give rain for most, snow on the hills with blizzards above about 300m.

In a cyclonic, Atlantic pattern like that we really need uppers approaching -10C to give snow to low levels. 

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Hi Jeff,

Pace and also orientation I think. GFS has been keeping those lows very flat riding the thermal boundary almost W to E, whereas other models skew them more to a SW/NE trajectory that promotes WAA and amplification.

The interaction with the Jet is crucial - in circumstances where the Jet is winding down and becoming unpredictable the it's no wonder then models are struggling with the mid-term. As the Jet weakens, so the feedback mechanism of blocks affecting the Jet rather than vice-versa becomes more pronounced.

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Joe,
Early Jan 1994 was cyclonic and produced snow to lower levels, even in Cent Southern England, with relatively high 850s. Kev posted some links a few days ago. I was in Basingstoke at the time. 4/5inches in just a few hours.

http://www.wetterzentrale.de/maps/archive/1994/noaa/NOAA_1_1994010618_2.png 

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Thanks Ben. The Accu people are talking about the trajectory of the weekend low being actually flatter (more W-E) because of deep cold and snow cover already in place over the Midwest. The US people and forecasts are usually better at both getting a handle on these and explaining them!

Jeff

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Of that snowfall, Trevor Harley says: "There was also a local heavy band of snow to the N and W of London on the 6-7th: Hitchin had 15 cm."

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Somewhat underwhelming output today, let’s hope the pub run gets things going again.

That is some winter storm Ian if it comes off.

http://old.wetterzentrale.de/pics/Rtavn2168.gif

Remember a week or so ago comments on how quiet, benign, dull the weather was close to that HP. Things could certainly be shaken up and rebalanced in the next week or two.

http://www.meteociel.fr/modeles/ecmwf/runs/2019011412/EDH1-240.GIF?14-0 

Normally I don’t pay massive amounts of attention to these means as they are a blend of all the scenarios so can hide details in individual members, however when the mean is notably different to the climatic norm they are worth a second glance.

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Looks like there's a strong signal for LP over the Mediterranean by the end of the run, which can only be good.

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also when the mean is similar to the op, looks like it could be our route to cold

Hi Jeff :)

That event looks like evaporative cooling associated with light winds to me? 

In my experience if the wind is strong and off the sea, us lowland dwellers really need uppers on our side (ideally approaching -10C for this part of the world at least, especially towards the coast). 

Very low pressure certainly allows uppers to be slightly higher (Jan 2015 as an example). 

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Hey chuckle. brief NAD Shutdown.

I mean GFS, GFS PARA, ECMWF, (ICON at 180 is not yet getting there!!) 00hrs Tuesday 22nd, calm if you check the ICON.

What will it be like on Monday and Tuesday 21-22 Jan. 2019?, We all enjoy making weather forecasts, there is cold air on Sunday and Monday and Tuesday looks like cold air may be around over the UK.

Wednesday and Thursday 23rd and 24th, is when GFS original and ECMWF Original bring about a undisturbed Polar Arctic Low from the Greenland and off SW Iceland area- making it dive to the UK, send the main weather fronts to Spain and SW France.

Heavy showers of rain and sleet plus snow for the hills during the said time period is being shown. Maybe areas lower down also might see some flakes of wet snow as well.

Towards the end of January- cold NE Winds and heavy snow showers are being offered by the prediction models.

Wednesday evening this week to Thursday and early on Friday there is proper cold weather and maybe a few or more chances of rain sleet and hill snow showers for some.

Keep watching - I can see the Original GFS is looking like a great hero, as on Sunday the aka 20th January the UK could be hit with some really cold air on cold NW flow as heavy wintry showers march SE from the NW across the UK.

Anything else that you may see in London is some thing to talk about as well..

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Just clicked on Data > Model Launcher, and got the following - with loads more in a similar vein. (Cutting and pasting it here seems to have nuked my sig.)

 

Server Error in '/' Application.

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Runtime Error

Description: An application error occurred on the server.

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crikey 1080 mb has to be a joke

http://www.meteociel.fr/modeles/jma.php?ech=192&mode=1&nh=0

 

 

ecm has a big problem with the amount of energy