Ilsington wrote:

On Jan 7, 1:01*pm, "Stan" wrote:
"Norman" wrote in message

...



Ilsington wrote:

On Jan 7, 11:34 am, Scott W wrote:
On 7 Jan, 10:42, "Keith (Southend)G"
wrote:

http://www.wzkarten3.de/pics/brack2.gif

What's the difference between a filled in front and one that isn't?
Was it done in a rush ;-)

Also wonder what effect those increased DAM's will have as the
weekend
progresses.

Keith (Southend)

I would have thought that the low-level temperature will remain very
cold because the source of the air at ground-level is so cold -
perhaps the worst we can expect is snow pellets
Keith,
See my earlier post. The warm advection is at upper levels so the
surface temperatures will be still low as the 850mb thickness is not
going to change that much. The event is similar to Jan 87 and although
the snow may be light, there could easily be heavier outbreaks hence
the weather warnings for both Sunday and Monday and indeed it could go
into Tuesday; interesting time.
Pete T

Wasn't the Jan 87 event associated with deep cold air with 1000-500
thicknesses
down to 500 dam and even lower? The next few days won't be anything like
that.

Norman

You are right however read up on the '47 winter when the snow was caused by
these upper fronts making 1947 snowiest winter of 20th century

Norman,
You are of course correct, but the real widespread snow, ie away from
the coasts was as a result of the upper atmosphere warming up. In
Berkshire we had a bitterly cold day on the Weds, but no snow. The day
after the upper air warmed up and we had 10cm of blowing snow.
Pete

Yes, I was really only thinking about the very cold clear day with the very low
max temps. Without going into my records I can't remember what followed. From
what you say, it was indeed upper warm advection eventually producing snow. I
should have engaged my brain before typing!

It will be interesting to see how this weekend evolves. I have a particular
interest as my daughter and her partner are planning to drive up here from the
London area on Sunday. That might not be the best of plans :-(

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.