Model Output Discussion

[cooling climate]

Agreed ... Come on Paul plzzzz it will save a lot of off topic posts

Monday would be early enough to do that if at all.

The depth of the low and position could change significantly over the next

couple of days.

[Costa Del Fal]

If the 06z comes true, the downgrades for next week begin with much less snow being shown for here. Lol.

[conor123]

Perhaps there is a light at the end of the tunnel with the potential for high pressure to settle to over us around 5-6th April.

Monday-Tuesdays snow event is starting to be downgraded to something more realistic now, i expect further changes to come.

[snowmadchrisuk]

Perhaps there is a light at the end of the tunnel with the potential for high pressure to settle to over us around 5-6th April.

Monday-Tuesdays snow event is starting to be downgraded to something more realistic now, i expect further changes to come.

Yes middle ground situation . I was slammed for suggesting such a thing last week. Still cold for Scotland though. (Although March Snowfall in Scotland is normal. )

[Thundery wintry showers]

It depends on what we consider to be "downgrading"- I think the chances of a substantial spell of "cold rain" for many have certainly downgraded, with the front moving out of the way for Tuesday instead of hanging around until Wednesday. If this trend continues then flooding should be less of an issue. But chances of snow have upgraded, because the cold polar air with sunshine and wintry showers is progged to last from Tuesday to Thursday, so three days instead of two.

Easter weekend is starting to look cool and showery with a slight chance of snow but probably less cold than midweek this coming week.

[frostyjoe]

It depends on what we consider to be "downgrading"- I think the chances of a substantial spell of "cold rain" for many have certainly downgraded, with the front moving out of the way for Tuesday instead of hanging around until Wednesday. If this trend continues then flooding should be less of an issue. But chances of snow have upgraded, because the cold polar air with sunshine and wintry showers is progged to last from Tuesday to Thursday, so three days instead of two.

Easter weekend is starting to look cool and showery with a slight chance of snow but probably less cold than midweek this coming week.

so i could see snow then? were is most likely.

[Cheese Rice]

I was looking at the snow time lapses from the big American snowstorms, and on every video the snow melts during the day even though it is still snowing, and I think this will be very much the case on Monday. Unless the PPN is as heavy as shown on the GFS then temporary accumulations are likely when the snow gets heavier only to melt during lighter snowfall. Around 3PM on-wards I would say is the best chance for some deep snowfall, fortunately the PPN is over me from 3PM-12 with some very heavy snow likely.

ATM I am in prime position for some decent snowfall, the last few runs have been great for this area, hopefully there wont be anymore changes as it is perfect as it is.

[phil nw.]

I was looking at the snow time lapses from the big American snowstorms, and on every video the snow melts during the day even though it is still snowing, and I think this will be very much the case on Monday. Unless the PPN is as heavy as shown on the GFS then temporary accumulations are likely when the snow gets heavier only to melt during lighter snowfall. Around 3PM on-wards I would say is the best chance for some deep snowfall, fortunately the PPN is over me from 3PM-12 with some very heavy snow likely.

ATM I am in prime position for some decent snowfall, the last few runs have been great for this area, hopefully there wont be anymore changes as it is perfect as it is.

Monday looks a dreadfull day for much of England and Wales with a lot of rain- and cold for N.England.

http://www.wetterzentrale.de/pics/Rtavn604.png

http://www.wetterzentrale.de/pics/Rtavn6017.png

Snowfall looks limited for low ground on 006z run to later Tues.before the Percip. dies out overnight.

http://www.wetterzentrale.de/pics/Rtavn7817.png

http://www.wetterzentrale.de/pics/Rtavn7810.png

http://www.wetterzentrale.de/pics/Rtavn784.png

The dewpoints look too high until much of the rain has passed.

[frostyjoe]

Monday looks a dreadfull day for much of England and Wales with a lot of rain- and cold for N.England.

http://www.wetterzen...cs/Rtavn604.png

http://www.wetterzen...s/Rtavn6017.png

Snowfall looks limited for low ground on 006z run to later Tues.before the Percip. dies out overnight.

http://www.wetterzen...s/Rtavn7817.png

http://www.wetterzen...s/Rtavn7810.png

http://www.wetterzen...cs/Rtavn784.png

The dewpoints look too high until much of the rain has passed.

i think we could get snow outta that on tuesday it shows 4c for us then and the rain over us hmm!

[Backtrack]

i think we could get snow outta that on tuesday it shows 4c for us then and the rain over us hmm!

I think at 4c, it would rain...

[Cheese Rice]

Monday looks a dreadfull day for much of England and Wales with a lot of rain- and cold for N.England.

http://www.wetterzen...cs/Rtavn604.png

http://www.wetterzen...s/Rtavn6017.png

Snowfall looks limited for low ground on 006z run to later Tues.before the Percip. dies out overnight.

http://www.wetterzen...s/Rtavn7817.png

http://www.wetterzen...s/Rtavn7810.png

http://www.wetterzen...cs/Rtavn784.png

The dewpoints look too high until much of the rain has passed.

I disagree, evaporating cooling will play a big part in the snowfall, the precipitation looks very heavy and with cold air undercutting the front there would easily be snowfall. For low ground it is questionable but to high ground (200m) it will definitely snow on Monday/Tuesday, with several cm's likely, I'm almost certain I will get snow.

This chart shows 12cm for ground 200m.

[liamcymro]

I'm at 223m above sea-level in North West Wales, Gwynedd - so looking quite good for snow =)

[Costa Del Fal]

i think we could get snow outta that on tuesday it shows 4c for us then and the rain over us hmm!

Unless you have a dewpoint below 0c then you have no chance of snow. 4c and 3c dewpoint for example will give you plenty of rain!

All this excitment over some snow which will only melt so quickly afterwards (thats if it sticks anyway!)

I disagree, evaporating cooling will play a big part in the snowfall, the precipitation looks very heavy and with cold air undercutting the front there would easily be snowfall. For low ground it is questionable but to high ground (200m) it will definitely snow on Monday/Tuesday, with several cm's likely, I'm almost certain I will get snow.

This chart shows 12cm for ground 200m.

Note those charts say experimental. I dont usually follow them tbh.

[Cheese Rice]

Unless you have a dewpoint below 0c then you have no chance of snow. 4c and 3c dewpoint for example will give you plenty of rain!

All this excitment over some snow which will only melt so quickly afterwards (thats if it sticks anyway!)

Note those charts say experimental. I dont usually follow them tbh.

I don't really take much notice of them, but it shows there is a risk.

[Costa Del Fal]

I don't really take much notice of them, but it shows there is a risk.

It is a good indication of where there will be settling snow i think. Snow accumulations forecasts never seem right here. We always seem to get less than forecast!

[Nights King]

Meto Show snow for tue/wed for whole west country almost but there is not warning out for us.

I am just hopeful of a last flirt with winter before spring proper turns up, possible I expect on hills and moors of west country.

[frostyjoe]

Unless you have a dewpoint below 0c then you have no chance of snow. 4c and 3c dewpoint for example will give you plenty of rain!

All this excitment over some snow which will only melt so quickly afterwards (thats if it sticks anyway!)

Note those charts say experimental. I dont usually follow them tbh.

That's the air temp which most likely under cloudy skies will be 2-3c and I just want to see a white hill

[Thundery wintry showers]

10123 lives on relatively high ground and to be fair, a setup which screams "cold rain" at low levels could well be conducive to falling and lying snow even with just a modest amount of altitude.

But the usual issue with these setups is indeed the dewpoints, for the general rule of thumb is that the lower the dewpoint, the less cold it has to be in order for it to snow. In such frontal zones to the south of the Arctic airmass, dewpoints are often near or above freezing meaning that even though the daytime maximum might be just 5C, you get a lot of rain because it needs to be close to freezing for it to snow. In contrast in the Arctic airmass itself dewpoints often fall well below freezing, so even though temperatures may rise to 7 or 8C in the sunshine, showers will often fall as snow or hail.

[Harsh Climate]

I don't really take much notice of them, but it shows there is a risk.

Through past experiences if things stay the same your pretty much guaranteed a covering tuesday I think even for me at ground just below 400ft Im expecting atleast a light or slushy covering at some stage early next week.

Its places like hull that shouldnt do too well....

[damianslaw]

Models beginning to show the low pressure transferring slightly quicker into the North Sea than being showed yesterday, which means precipitation may not be as long lasting as some were thinking, but more importantly the quicker transfer will mean a quicker allowance for the colder air to embed itself and last longer.

Places to the north and north west of the frontal zone will be best placed for seeing any low level snow. Altitude as always will play a big part and also the intenseness of the precipitation. Evaporative cooling will be strongest in the heaviest precipitation which at this stage looks likely over central northern england i.e. Pennine areas. Dewpoints will be lower in the arctic airmass.

If you have a little bit of height and you are located in Pennine areas, I think chances of snow settling look very high as Tuesday progresses.

Scotland will see some heavy snow showers to low levels almost anywhere I suspect later Tuesday and overnight into Wednesday.

[Backtrack]

That's the air temp which most likely under cloudy skies will be 2-3c and I just want to see a white hill

Hm, no that wont be the case, if the GFS says 4c then it will be around that.

[Costa Del Fal]

That's the air temp which most likely under cloudy skies will be 2-3c and I just want to see a white hill

Lol, the GFS says what it says according to the expected conditions. If it predicts 4c, it predicts 4c!

Edited March 27, 2010 by Blizzards

[Cheshire Freeze]

Some nice convective potential shown on the 12z GFS for next week. Polar northwesterly airstream would bring some great cloudscapes, along with some wintry showers of sleety rain, hail and wet snow in any heavier showers. Lovely jubbly

Aaron

Edited March 27, 2010 by CreweCold

[johnholmes]

The 12z for the precip Mon-Wed has another change, its split the fall into 2 distinct time periods, something the 06z had started, 15mm Mon 03z-Tue 03z and 21mm Tue 09z-Wed 09z

The overall trend in the total continues downwards, its now 36mm from the 64mm on the 18z yesterday.

[Eugene]

Some nice convective potential shown on the 12z GFS for next week. Polar northwesterly airstream would bring some great cloudscapes, along with some wintry showers of sleety rain, hail and wet snow in any heavier showers. Lovely jubbly

Yes the potential is there but the maxs look very cold on GFS 12Z for wednesday to friday which indicates to me not much sunshine as temps can rise to 9C this time of year, GFS 12Z certainly a chilly run almost throughout with no warmth, it would bugger up the people forecasting CET's of almost 10C thats for sure

Edited March 27, 2010 by Eugene