" Jill." wrote in message
...

Nigel.

If someone has the time and the inclination would it be possible to
explain
the map Nigel has indicated more simply to those of us who are
beginners
here?

The two key charts that are being discussed here a-

1. Sea Level Pressure and 1000-500 mb Thickness.

2. 850mb Temperature, Humidity & Wind.

The first chart is a fairly classic representation of some variables:
the alternating broad/thin lines with two figures on some of them in
black boxes are isobars; the chart shows high pressure WSW of Ireland
and complex low pressure over Scandinavia, so that implies a northerly
or north-westerly gradient flow (but overland, the surface wind will be
backed off from that - NW or WNW'ly).

The very thin lines with three-figure numbers on them (5xx mostly) are
the thickness values - in rough terms (see the FAQ/Glossary), the lower
the figure, the colder the air. This particular chart appears to show a
closed 516 dekametre pool of cold air (implied for the lower
troposphere - i.e. the lowest 5km or so of the atmosphere), which would
imply a high degree of 'wintriness' both for temperatures and
precipitation.

The second chart shows wind arrows at 850 millibars (roughly 5000ft or
1500m) a good level to chase around air masses, as long as you remember
that near-surface air can sometimes become 'uncoupled' from this level-
not applicable in this case I would have thought though. The lines are
isotherms of actual temperature at this level: so for the area of the
British Isles, we have values of between -6 and -10 (lower than -10
around the Wash); Very crudely, if you assume 2C per thousand feet, this
implies a surface maximum temperature of around zero in the coldest
spots - but with lots of caveats which I will let others drool over (the
sun is very powerful at this time of year).

You'll find these, and some other stuff, discussed at:-

http://homepage.ntlworld.com/booty.w...els/topics.htm

HTH

Martin.


--
FAQ & Glossary for uk.sci.weather at:-
http://homepage.ntlworld.com/booty.weather/uswfaqfr.htm

"Martin Rowley" wrote in
message

Very crudely, if you assume 2C per thousand feet, this
implies a surface maximum temperature of around zero in the coldest
spots - but with lots of caveats which I will let others drool over (the
sun is very powerful at this time of year).


True, one of my dodgy solar garden lights was still going strong well
after 22Z last night.

Jon.


--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

"Martin Rowley" wrote in
message

Very crudely, if you assume 2C per thousand feet, this
implies a surface maximum temperature of around zero in the coldest
spots - but with lots of caveats which I will let others drool over (the
sun is very powerful at this time of year).


True, one of my dodgy solar garden lights was still going strong well
after 22Z last night.

Jon.


--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

"Martin Rowley" wrote in
message

Very crudely, if you assume 2C per thousand feet, this
implies a surface maximum temperature of around zero in the coldest
spots - but with lots of caveats which I will let others drool over (the
sun is very powerful at this time of year).


True, one of my dodgy solar garden lights was still going strong well
after 22Z last night.

Jon.


--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

"Martin Rowley" wrote in
message

Very crudely, if you assume 2C per thousand feet, this
implies a surface maximum temperature of around zero in the coldest
spots - but with lots of caveats which I will let others drool over (the
sun is very powerful at this time of year).


True, one of my dodgy solar garden lights was still going strong well
after 22Z last night.

Jon.


--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

"Ian Bingham" wrote in message
...
According to www2.wetter3.de/animation, the north coast of Scotland is to
get a thickness of about 510dam with a 850mb temp of ms12C on Friday
April
8th at 0000z. Even Kent is to have 524dam at that time. It will be
interesting to see if this comes about. Somehow I doubt it!

Ian (Aberdeen).

"Ian Bingham" wrote in message
...
According to www2.wetter3.de/animation, the north coast of Scotland is to
get a thickness of about 510dam with a 850mb temp of ms12C on Friday
April
8th at 0000z. Even Kent is to have 524dam at that time. It will be
interesting to see if this comes about. Somehow I doubt it!

Ian (Aberdeen).

"Ian Bingham" wrote in message
...
According to www2.wetter3.de/animation, the north coast of Scotland is to
get a thickness of about 510dam with a 850mb temp of ms12C on Friday
April
8th at 0000z. Even Kent is to have 524dam at that time. It will be
interesting to see if this comes about. Somehow I doubt it!

Ian (Aberdeen).

"Ian Bingham" wrote in message
...
According to www2.wetter3.de/animation, the north coast of Scotland is to
get a thickness of about 510dam with a 850mb temp of ms12C on Friday
April
8th at 0000z. Even Kent is to have 524dam at that time. It will be
interesting to see if this comes about. Somehow I doubt it!

Ian (Aberdeen).