"Mike Tullett" wrote in
message ...
On Sun, 03 Apr 2005 10:09:21 +0100, Nigel Morgan wrote in
If it happens, that will be the first time in my lifetime that the
daytime temp
stays below freezing this far into April. The last time the daytime
temp stayed
below freezing was in the first three days of April 1986!

I don't think we are looking at sub-zero daytime temps, given that
scenario
in April. If the chart does come off then temps of 3-5 look likely to
me
(with a -10C 850mb temp). Any solar heating of the surface should
take the
temp well above 0C.

Hi, Mike and Nigel,

Sub zero in April, where do you live Nigel? The lowest max I recorded in
April at my old site - Low Etherley 160metres - was 2.3C (2.8C in 1986
Nigel) and at Copley 253metres is 3.1C. Those records go back to 1970.

I think April 1917 could have had some sub zero highs, but these days,
going by my figures, you would need elevations beyond 500 metres and
it's becoming more difficult each year.

We shall see but my money is on 5C highs, or more, here.

Best wishes,

--
Ken Cook, Copley (5miles north of Barnard Castle), County Durham.
830ft
http://mysite.wanadoo-members.co.uk/copley
(MO climat. site updated before 10Z and 19Z daily)
kencookATcopleydurham.freeserve.co.uk
(All times GMT)

"Mike Tullett" wrote in
message ...
On Sun, 03 Apr 2005 10:09:21 +0100, Nigel Morgan wrote in
If it happens, that will be the first time in my lifetime that the
daytime temp
stays below freezing this far into April. The last time the daytime
temp stayed
below freezing was in the first three days of April 1986!

I don't think we are looking at sub-zero daytime temps, given that
scenario
in April. If the chart does come off then temps of 3-5 look likely to
me
(with a -10C 850mb temp). Any solar heating of the surface should
take the
temp well above 0C.

Hi, Mike and Nigel,

Sub zero in April, where do you live Nigel? The lowest max I recorded in
April at my old site - Low Etherley 160metres - was 2.3C (2.8C in 1986
Nigel) and at Copley 253metres is 3.1C. Those records go back to 1970.

I think April 1917 could have had some sub zero highs, but these days,
going by my figures, you would need elevations beyond 500 metres and
it's becoming more difficult each year.

We shall see but my money is on 5C highs, or more, here.

Best wishes,

--
Ken Cook, Copley (5miles north of Barnard Castle), County Durham.
830ft
http://mysite.wanadoo-members.co.uk/copley
(MO climat. site updated before 10Z and 19Z daily)
kencookATcopleydurham.freeserve.co.uk
(All times GMT)

"Mike Tullett" wrote in
message ...
On Sun, 03 Apr 2005 10:09:21 +0100, Nigel Morgan wrote in
If it happens, that will be the first time in my lifetime that the
daytime temp
stays below freezing this far into April. The last time the daytime
temp stayed
below freezing was in the first three days of April 1986!

I don't think we are looking at sub-zero daytime temps, given that
scenario
in April. If the chart does come off then temps of 3-5 look likely to
me
(with a -10C 850mb temp). Any solar heating of the surface should
take the
temp well above 0C.

Hi, Mike and Nigel,

Sub zero in April, where do you live Nigel? The lowest max I recorded in
April at my old site - Low Etherley 160metres - was 2.3C (2.8C in 1986
Nigel) and at Copley 253metres is 3.1C. Those records go back to 1970.

I think April 1917 could have had some sub zero highs, but these days,
going by my figures, you would need elevations beyond 500 metres and
it's becoming more difficult each year.

We shall see but my money is on 5C highs, or more, here.

Best wishes,

--
Ken Cook, Copley (5miles north of Barnard Castle), County Durham.
830ft
http://mysite.wanadoo-members.co.uk/copley
(MO climat. site updated before 10Z and 19Z daily)
kencookATcopleydurham.freeserve.co.uk
(All times GMT)

On Sun, 03 Apr 2005 10:09:21 +0100, Nigel Morgan wrote in
news
That's nothing! Grads (http://grads.iges.org/pix/euro.144hr.html) shows sub 516
DAM air with 850mB temp of -10C over eastern England for 00Z Sat 9th! Not
surprising when the jet stream is roaring straight down from the north pole! If
that happens, looks like the air temp won't get above freezing here at all
during the day!

If it happens, that will be the first time in my lifetime that the daytime temp
stays below freezing this far into April. The last time the daytime temp stayed
below freezing was in the first three days of April 1986!

I don't think we are looking at sub-zero daytime temps, given that scenario
in April. If the chart does come off then temps of 3-5 look likely to me
(with a -10C 850mb temp). Any solar heating of the surface should take the
temp well above 0C.

--
Mike 55.13°N 6.69°W Coleraine posted to uk.sci.weather 03/04/2005 09:40:53 UTC

On Sun, 03 Apr 2005 10:09:21 +0100, Nigel Morgan wrote in
news
That's nothing! Grads (http://grads.iges.org/pix/euro.144hr.html) shows sub 516
DAM air with 850mB temp of -10C over eastern England for 00Z Sat 9th! Not
surprising when the jet stream is roaring straight down from the north pole! If
that happens, looks like the air temp won't get above freezing here at all
during the day!

If it happens, that will be the first time in my lifetime that the daytime temp
stays below freezing this far into April. The last time the daytime temp stayed
below freezing was in the first three days of April 1986!

I don't think we are looking at sub-zero daytime temps, given that scenario
in April. If the chart does come off then temps of 3-5 look likely to me
(with a -10C 850mb temp). Any solar heating of the surface should take the
temp well above 0C.

--
Mike 55.13°N 6.69°W Coleraine posted to uk.sci.weather 03/04/2005 09:40:53 UTC

On Sun, 03 Apr 2005 10:09:21 +0100, Nigel Morgan wrote in
news
That's nothing! Grads (http://grads.iges.org/pix/euro.144hr.html) shows sub 516
DAM air with 850mB temp of -10C over eastern England for 00Z Sat 9th! Not
surprising when the jet stream is roaring straight down from the north pole! If
that happens, looks like the air temp won't get above freezing here at all
during the day!

If it happens, that will be the first time in my lifetime that the daytime temp
stays below freezing this far into April. The last time the daytime temp stayed
below freezing was in the first three days of April 1986!

I don't think we are looking at sub-zero daytime temps, given that scenario
in April. If the chart does come off then temps of 3-5 look likely to me
(with a -10C 850mb temp). Any solar heating of the surface should take the
temp well above 0C.

--
Mike 55.13°N 6.69°W Coleraine posted to uk.sci.weather 03/04/2005 09:40:53 UTC

On Sun, 03 Apr 2005 10:09:21 +0100, Nigel Morgan wrote in
news
That's nothing! Grads (http://grads.iges.org/pix/euro.144hr.html) shows sub 516
DAM air with 850mB temp of -10C over eastern England for 00Z Sat 9th! Not
surprising when the jet stream is roaring straight down from the north pole! If
that happens, looks like the air temp won't get above freezing here at all
during the day!

If it happens, that will be the first time in my lifetime that the daytime temp
stays below freezing this far into April. The last time the daytime temp stayed
below freezing was in the first three days of April 1986!

I don't think we are looking at sub-zero daytime temps, given that scenario
in April. If the chart does come off then temps of 3-5 look likely to me
(with a -10C 850mb temp). Any solar heating of the surface should take the
temp well above 0C.

--
Mike 55.13°N 6.69°W Coleraine posted to uk.sci.weather 03/04/2005 09:40:53 UTC

" 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

" 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

" 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