Monday's Low

[xmetman]

It's still a long way off I know but the situation on Monday is looking very reminiscent of the Christmas day snowstorm 1927

I 

[xmetman]

Not that I remember it of course!

[xmetman]

Of course I was only guessing at what the chart for Christmas day 1927 may have looked like - but now that I've seen the DWR it's not a bad match.

[Martin Rowley [West Moors/East Dorset]]

... I agree, though it's not that far away in terms of time: if you take the three 'extended' models at face value (GFS, EC, UKMO), then they ALL come up with a similar solution (latest output) and given the pool of cold air floating around to the north etc., I'd be paying close attention to conditions Monday.

And the MO will have to warn /well/ ahead of time (late today or Saturday - Saturday indeed may be too late) - because people travel/plan so far ahead on Sunday/Monday.

Martin.

[Dave C]

I suppose you would have to knock off 1C for being 1927 which could make all of the difference between rain and snow?

[xmetman]

I can't imagine the SST's in 1927 looking like this.

It's no wonder that many of the showers today at Lerwick were of rain, although that's an interesting strip of colder than average water due east of Iceland.

[John Hall]

I remember reading that the rain turned to snow around dusk over SE England, so about 9 hours after the time of that chart.

[xmetman]

Met Office news release:-

"Further unsettled and potentially disruptive weather is possible for some southern areas early next week. Storm Ana, named by the Spanish weather service, is expected to move into France on Monday and may bring a spell of wet and windy weather to parts of southern England with the potential for more snow."

[Martin Rowley [West Moors/East Dorset]]

.... this is what the EC OP 12Z run today (8th) makes of snow accumulation by the VT time indicated: much of the accumulation across southern England has occurred (in the model remember) in the 6 hours after 11/0600Z (Monday). The dark blue shading is 6 to 10 cm, purple is 10 or more cm; before getting too excited though, the corresponding 'Significant Weather' panels show 'Mixed rain/snow, moderate or heavy' rather than full-on snowfall. I suspect this will be too pessimistic, BUT, even a few cm of slushy deposit across the main M-way networks at this time of day will be, how shall we put it, challenging! Martin.

[Martin Rowley [West Moors/East Dorset]]

... EC OP has backed-off considerably (for the south) from yesterday's run: this looks much more plausible and is in line with other products/centres. Still tricky but not overly dramatic - the effect of the snowfall on Sunday for areas Wales, Midlands, East of England, Lancs/Cheshire plain etc., is clear and consistent with earlier runs. Martin.

[xmetman]

Yes, Martin, sadly I think I have to agree with you.

[xmetman]

Came across this question asked of Hubert Lamb in an interview.

It strikes me that a lot of people who have an interest in weather were inspired by snowy cold winters during their childhood, I certainly know that I was by the winter of 1962-63.

[John Hall]

It seems strange that, though the odds may be against a disruptive snowfall i the south on Monday, there's so far been no yellow warning.  One would have thought that there was a significant enough risk to justify one.

[John Hall]

On Friday, 8 December 2017 13:01:00 UTC, Dave C wrote:

I suppose you would have to knock off 1C for being 1927 which could make all of the difference between rain and snow?

Also remember that it would be two weeks earlier than the 1927 snowstorm,  which would probably make another 0.5-1C of difference given an identical synoptic situation.