Will Hand wrote:
This maybe a tad premature given the present situation but I will admit
now that my prediction for "widespread lowland snow" this week has
turned out to be a poor one.

I've looked back, and at the time there was great potential and the
models had been consistent and the synoptics indeed were not far out.
But what happened was that the temperature was one degree higher raising
the wet-bulb freezing level by 200m or so and many places got cold
rain/sleet instead of snow. The trouble is that when you go for snow and
this happens there is no place to hide!

But why was it warmer than many runs were initially showing? I think the
answer lies in our old friend SST. The air feeding into the low complex,
which was perhaps a shade further west than I thought might happen,
spent more time over the ocean going west over the top and warmed up in
the lowest layers. It is only now as the deep cold polar air behind the
upper trough comes east that we will get the widespread sub 200m
wet-bulb freezing levels that I expected Tuesday/Wednesday.

Ah well, I have a thick skin and I have been wrong many times before and
I will be wrong again, but I won't stop trying in very difficult
situations. Fortunately at least for me locally I won't be quite as
wrong but then it is easier forecasting for upland areas - sometimes.

Will

Nothing to be ashamed of. I thought last week that anywhere from the
midlands northward would have had widespread snow. It was always very
borderline in the SE though.

The GFS seems to have this cold low sticking around for the next few
days with the 522dm line near or south of the south coast so there is
still potential for a decent snowfall anywhere. Having said that the Met
Office seem to be forecasting surface temperatures of 6C by day which
would rule out any snowfall settling - surprised that temps would be
that high with such a low thickness.

I think what you should take into account in your forecasts is that in
the middle of January I ordered a pair of studded winter tyres for my
mountain bike in preparation for any further cold snaps; this probably
has knackered the chances of any lying snow for the rest of the winter :-)

"Will Hand" wrote in message
...
This maybe a tad premature given the present situation but I will admit
now that my prediction for "widespread lowland snow" this week has turned
out to be a poor one.

I've looked back, and at the time there was great potential and the models
had been consistent and the synoptics indeed were not far out. But what
happened was that the temperature was one degree higher raising the
wet-bulb freezing level by 200m or so and many places got cold rain/sleet
instead of snow. The trouble is that when you go for snow and this happens
there is no place to hide!

But why was it warmer than many runs were initially showing? I think the
answer lies in our old friend SST. The air feeding into the low complex,
which was perhaps a shade further west than I thought might happen, spent
more time over the ocean going west over the top and warmed up in the
lowest layers. It is only now as the deep cold polar air behind the upper
trough comes east that we will get the widespread sub 200m wet-bulb
freezing levels that I expected Tuesday/Wednesday.

Ah well, I have a thick skin and I have been wrong many times before and I
will be wrong again, but I won't stop trying in very difficult situations.
Fortunately at least for me locally I won't be quite as wrong but then it
is easier forecasting for upland areas - sometimes.

Will
--

You're not the only one. I had forecast lots of snow showers in this area
for this week on my website's local forecast. It's been bone dry so far.

If we got it right 100% of the time, people would ask us for the national
lottery numbers.

Dave Cornwell wrote:
"Len Wood" wrote in message
...
On Feb 17, 9:23 pm, "Will Hand" wrote:
This maybe a tad premature given the present situation but I will admit
now
that my prediction for "widespread lowland snow" this week has turned out
to
be a poor one.

I've looked back, and at the time there was great potential and the models
had been consistent and the synoptics indeed were not far out. But what
happened was that the temperature was one degree higher raising the
wet-bulb
freezing level by 200m or so and many places got cold rain/sleet instead
of
snow. The trouble is that when you go for snow and this happens there is
no
place to hide!

But why was it warmer than many runs were initially showing? I think the
answer lies in our old friend SST. The air feeding into the low complex,
which was perhaps a shade further west than I thought might happen, spent
more time over the ocean going west over the top and warmed up in the
lowest
layers. It is only now as the deep cold polar air behind the upper trough
comes east that we will get the widespread sub 200m wet-bulb freezing
levels
that I expected Tuesday/Wednesday.

Ah well, I have a thick skin and I have been wrong many times before and I
will be wrong again, but I won't stop trying in very difficult situations.
Fortunately at least for me locally I won't be quite as wrong but then it
is
easier forecasting for upland areas - sometimes.

Will
--

You should worry - I got everyone to call off their golf today ,on the best
day of the winter in these parts!
It is very frustrating though that it always seems to go 1-2C warmer than
expected, never the other way. I don't know why they don't do all the clever
stuff then add one degree for luck!
Dave



Might be interesting to do a formal analysis of the model forecasts to
see if there is a bias present at longer lead times. I have a suspicion
that it is illusionary fuelled by frustration at the promise of snow
that hasn't come off several times. Would you have noticed if the models
had forecast 6C with rain and it was 4C with rain?

In article ,
Will Hand writes:
This maybe a tad premature given the present situation
snip

Yep. By the time we reach next Tuesday we could all be acclaiming your
genius.

Hopefully everyone here will realise that forecasting marginal snow
situations is very difficult and will go wrong occasionally.
--
John Hall
"Acting is merely the art of keeping a large group of people
from coughing."
Sir Ralph Richardson (1902-83)

In article
,
Bonos Ego writes:
Will,

I think your forecast was excellent, I just assumed you had made a
typing error with the date, have you seen the latest for Monday 22nd
from the GFS?

http://expert.weatheronline.co.uk/da...10/02/17/basis
18/enen/rart_10022206_1718.gif?a7cc7411f96ff6b3539459ff6e9 4f59a
http://expert.weatheronline.co.uk/da...10/02/17/basis
18/enen/rart_10022212_1718.gif?acaf9297e3222271074e96e4520 f585a

Now with support from the ECMWF, though the UKMO model takes a different
view.
--
John Hall
"Acting is merely the art of keeping a large group of people
from coughing."
Sir Ralph Richardson (1902-83)

In article ,
Dave Cornwell writes:
You should worry - I got everyone to call off their golf today ,on the best
day of the winter in these parts!

Amazing, isn't it. Tuesday horrid in the SE, Wednesday glorious, and
today it's back to horrid again.
--
John Hall
"Acting is merely the art of keeping a large group of people
from coughing."
Sir Ralph Richardson (1902-83)

In article ,
Adam Lea writes:
The GFS seems to have this cold low sticking around for the next few
days with the 522dm line near or south of the south coast so there is
still potential for a decent snowfall anywhere. Having said that the
Met Office seem to be forecasting surface temperatures of 6C by day
which would rule out any snowfall settling - surprised that temps would
be that high with such a low thickness.

At this time of year the sun is getting some real power, so an hour or
two of sun will cause the temperature to pop up. But it's only the air
near the surface that gets substantially warmed, so that if the sun goes
in the temperature can fall quite quickly.
--
John Hall
"Acting is merely the art of keeping a large group of people
from coughing."
Sir Ralph Richardson (1902-83)

On Feb 17, 10:20*pm, Bonos Ego wrote:
Will,

I think your forecast was excellent, I just assumed you had made a
typing error with the date, have you seen the latest for Monday 22nd
from the GFS?

http://expert.weatheronline.co.uk/da...2010/02/17/bas...

Bonos how is the one from Met Monkey that you linked us to explaining
away his complete snowy armageddon forecast? Will's forecast was tame
compared to that one!

Yes that little low is now shown as tracking further north than was the
case on earlier runs, and the Met Office warning now issued for Monday
seems to reflect that. It will be interesting to see where the 12Z ECMWF
puts the low.
--
John,

If it's smack bang over Weston Coyney we still won't get a heavy fall of
snow
Snow warning yesterday for up to 6cms, we managed a temporary light covering
last night!
Today's warning was for 10cms on higher ground, we've had a light dusting
this evening and now they have put the mockers on us again and issued
another damn warning for Monday
Maybe over the weekend we will get more snow from the wintry showers without
any snow warnings, though I doubt it!!

Graham

In article ,
Graham writes:

Yes that little low is now shown as tracking further north than was the
case on earlier runs, and the Met Office warning now issued for Monday
seems to reflect that. It will be interesting to see where the 12Z ECMWF
puts the low.
--
John,

If it's smack bang over Weston Coyney we still won't get a heavy fall
of snow



But you wouldn't want it there, as that might put you in the milder air.
I would think that 50-100 miles to your south would be ideal.

Snow warning yesterday for up to 6cms, we managed a temporary light
covering last night!
Today's warning was for 10cms on higher ground, we've had a light
dusting this evening and now they have put the mockers on us again and
issued another damn warning for Monday

You seem to have been unlucky, in view of the reports from slightly
south of you.

Maybe over the weekend we will get more snow from the wintry showers
without any snow warnings, though I doubt it!!

Graham


Fingers crossed for you.
--
John Hall
"Acting is merely the art of keeping a large group of people
from coughing."
Sir Ralph Richardson (1902-83)