"John Hall" wrote in message
...
In article
,
Tudor Hughes writes:
On Jan 4, 12:04 pm, James Brown wrote:

And, er, remind me, when did the '47 Winter begin?...;-)- Hide quoted
text -

February. I was 4, but dont't remember it. The same could be
said of 1956, which I do remember, and 1986, which I remember even
better. I can't quite see what you're getting at. Surely these
events, whether or not significant, can occur at any time of the
winter?

Actually the 1947 winter began on about 23th January. But I'm sure
you're right that such events can occur at any time of year. (Though
there were an unusual number of really cold Februaries from the 1940s
onwards: 1947, 1956, 1963 and 1986 all had sub-zero CETs.)

And as late as Jan 18th 1947 the set-up appears to have been
mild and zonal.
--
Col

Bolton, Lancashire
160m asl

Am I right in saying that as it's been zonal now for several weeks over the the winter solstice period, when above 70N there is no daylight, the cold has been locked in the upper atmosphere of the Arctic, getting colder & colder, with no incursions of real cold in to the more temperate latitudes at the surface?

So as the warm air from the tropics, that is being advected up the western side of the UK by the High Pressure over Biscay into the Artic regions rises through the atmosphere, dislaces the cold Arctic air high in the upper polar atmosphere causing a SST, the now extremly cold & dense polar air sinks to the surface & heads South to replace the void left by the warm air from the tropics that first headed North?

SSW not SST.

In article ,
Col writes:

"John Hall" wrote in message
.. .
In article
,
Tudor Hughes writes:
On Jan 4, 12:04 pm, James Brown wrote:

And, er, remind me, when did the '47 Winter begin?...;-)- Hide quoted
text -

February. I was 4, but dont't remember it. The same could be
said of 1956, which I do remember, and 1986, which I remember even
better. I can't quite see what you're getting at. Surely these
events, whether or not significant, can occur at any time of the
winter?

Actually the 1947 winter began on about 23th January. But I'm sure
you're right that such events can occur at any time of year. (Though
there were an unusual number of really cold Februaries from the 1940s
onwards: 1947, 1956, 1963 and 1986 all had sub-zero CETs.)

And as late as Jan 18th 1947 the set-up appears to have been
mild and zonal.

Yes, there's a chart from mid-January 1947 in Gordon Manley's "Climate
and the British Scene" (illustrating a transient ridge of high pressure
IIRC) where one would have thought that there was no prospect of really
cold weather in the next couple of weeks. If the modern computer models
had been around then, I wonder how well they would have fared.

Out of interest, I looked up the values from the daily CET series that
Parker, Legg and Folland published in 1992. For the second half of
January 1947 they were (presumably max+min/2):

16th: 10.0
17th: 6.9
18th: 6.3
19th: 2.8
20th: 1.6
21st: 1.8
22nd: 1.0
23rd: 0.1
24th: -0.6
25th: -0.1
26th: -1.3
27th: -1.5
28th: -2.0
29th: -6.4
30th: -5.1
31st: -2.5

It's well-known that blocking seems to be more common in the second half
of the winter than in the second half, enough for the average February
rainfall to be substantially less than December's and January's, even
taking into account that February is a shorter month. I wonder if that
might indicate that mid to late January is a favoured time for SSW?
--
John Hall

"Whenever people agree with me I always feel I must be wrong."
Oscar Wilde

In article ,
Teignmouth writes:
Am I right in saying that as it's been zonal now for several weeks
over the the winter solstice period, when above 70N there is no
daylight, the cold has been locked in the upper atmosphere of the
Arctic, getting colder & colder, with no incursions of real cold in to
the more temperate latitudes at the surface?

ISTR that around the middle of December the blocking anticyclone which
had been giving the UK cold weather shifted further east, with the
result that we had a succession of lows grinding to a halt in our
vicinity. After another week or so the anticyclone either vanished
altogether or retreated so far east that it was no longer a factor, and
since then it's been relentlessly zonal.

So as the warm air from the tropics, that is being advected up the
western side of the UK by the High Pressure over Biscay into the
Artic regions rises through the atmosphere, dislaces the cold Arctic
air high in the upper polar atmosphere causing a SST, the now
extremly cold & dense polar air sinks to the surface & heads South
to replace the void left by the warm air from the tropics that first
headed North?

I don't know enough to say that's incorrect, but it doesn't seem
convincing to me.
--
John Hall

"Whenever people agree with me I always feel I must be wrong."
Oscar Wilde

In article ,
John Hall writes:
It's well-known that blocking seems to be more common in the second half
of the winter than in the second half,

Oops! But hopefully everyone knew what I meant.
--
John Hall

"Whenever people agree with me I always feel I must be wrong."
Oscar Wilde

John,

I didn't convince myself, but was wondering if that is what is actualy happening.

"Teignmouth" wrote in message
...
John,

I didn't convince myself, but was wondering if that is what is actualy
happening.


Hi David, it's not quite right, but we can chat about that sometime. It's
great to see people thinking about atmospheric dynamics though rather than
just model watching.

Will
--

"John Hall" wrote in message
...
In article ,
Col writes:

"John Hall" wrote in message
. ..
In article
,
Tudor Hughes writes:
On Jan 4, 12:04 pm, James Brown wrote:

And, er, remind me, when did the '47 Winter begin?...;-)- Hide quoted
text -

February. I was 4, but dont't remember it. The same could be
said of 1956, which I do remember, and 1986, which I remember even
better. I can't quite see what you're getting at. Surely these
events, whether or not significant, can occur at any time of the
winter?

Actually the 1947 winter began on about 23th January. But I'm sure
you're right that such events can occur at any time of year. (Though
there were an unusual number of really cold Februaries from the 1940s
onwards: 1947, 1956, 1963 and 1986 all had sub-zero CETs.)

And as late as Jan 18th 1947 the set-up appears to have been
mild and zonal.

Yes, there's a chart from mid-January 1947 in Gordon Manley's "Climate
and the British Scene" (illustrating a transient ridge of high pressure
IIRC) where one would have thought that there was no prospect of really
cold weather in the next couple of weeks. If the modern computer models
had been around then, I wonder how well they would have fared.

If this group had been around then, I wonder how many would have
written off winter by mid January

Out of interest, I looked up the values from the daily CET series that
Parker, Legg and Folland published in 1992. For the second half of
January 1947 they were (presumably max+min/2):

16th: 10.0
17th: 6.9
18th: 6.3
19th: 2.8
20th: 1.6
21st: 1.8
22nd: 1.0
23rd: 0.1
24th: -0.6
25th: -0.1
26th: -1.3
27th: -1.5
28th: -2.0
29th: -6.4
30th: -5.1
31st: -2.5

High pressure which started off over France moved north and east and
eventually became a classic Scandy high with bitterly cold easterlies.
--
Col

Bolton, Lancashire
160m asl

On Jan 5, 6:41*pm, John Hall wrote:
In article ,









*Col writes:

"John Hall" wrote in message
.. .
In article
,
Tudor Hughes writes:
On Jan 4, 12:04 pm, James Brown wrote:

And, er, remind me, when did the '47 Winter begin?...;-)- Hide quoted
text -

* * February. *I was 4, but dont't remember it. *The same could be
said of 1956, which I do remember, and 1986, which I remember even
better. *I can't quite see what you're getting at. *Surely these
events, whether or not significant, can occur at any time of the
winter?

Actually the 1947 winter began on about 23th January. But I'm sure
you're right that such events can occur at any time of year. (Though
there were an unusual number of really cold Februaries from the 1940s
onwards: 1947, 1956, 1963 and 1986 all had sub-zero CETs.)

And as late as Jan 18th 1947 the set-up appears to have been
mild and zonal.

Yes, there's a chart from mid-January 1947 in Gordon Manley's "Climate
and the British Scene" (illustrating a transient ridge of high pressure
IIRC) where one would have thought that there was no prospect of really
cold weather in the next couple of weeks. If the modern computer models
had been around then, I wonder how well they would have fared.

Out of interest, I looked up the values from the daily CET series that
Parker, Legg and Folland published in 1992. For the second half of
January 1947 they were (presumably max+min/2):

16th: 10.0
17th: 6.9
18th: 6.3
19th: 2.8
20th: 1.6
21st: 1.8
22nd: 1.0
23rd: 0.1
24th: -0.6
25th: -0.1
26th: -1.3
27th: -1.5
28th: -2.0
29th: -6.4
30th: -5.1
31st: -2.5

It's well-known that blocking seems to be more common in the first half
of the winter than in the second half, enough for the average February
rainfall to be substantially more than December's and January's, even
taking into account that February is a shorter month. I wonder if that
might indicate that mid to late January is a favoured time for SSW?

If that is what you meant; it keeps it in line with the saying that
February fills ditches.