General Model Output Discussion

[Snow storm]

IMO the charts are a real downer tonight, after a promising 06Z.

Ok so they're not that mild, but high 850's on Weds could seriously start to reduce the strength of the cold pool of air over us. This cold pool is sacred in giving us snowfall anywhere, otherwise it becomes the typical marginal rain/sleet scenario in the south, until cold air becomes established.

The low at +108 hours really P*5sses me off. There is so much cold around over Northern Europe, and one little, pathetic low/trough thing is enough to keep it from the UK, and up the H850's to +5.

Edited January 8, 2010 by Snow storm

[Just Below Zero]

ECM 12z looks to me to be a even larger teapot evolution to a traditional winter synoptic.

Other models look more in keeping particularly the lesser thought of ones.

I expect a slider eventually filling before a LP tracks NE from the channel giving two snow events before the second turns to rain

Edited January 8, 2010 by Just Below Zero

[nick sussex]

IMO the charts are a real downer tonight, after a promising 06Z.

Ok so they're not that mild, but high 850's on Weds could seriously start to reduce the strength of the cold pool of air over us. This cold pool is sacred in giving us snowfall anywhere, otherwise it becomes the typical marginal rain/sleet scenario in the south, until cold air becomes established.

The low at +108 hours really P*5sses me off. There is so much cold around over Northern Europe, and one little, pathetic low/trough thing is enough to keep it from the UK, and up the H850's to +5.

Judging by your location in your avatar you're inland which will help if the channel low verifies. As for the 850's its inevitable that these will rise as the upper cold pool becomes exhausted. However there is a good surface cold pool to draw on,in mainland europe you can get snow off dam as much as 540. For the UK i'd say with the set up 536 might be okay. The actual trajectory of the low is quite favourable as its likely to draw a flow ahead of it from the east or se which will bring some drier air in and lower the dew point.

Edited January 8, 2010 by nick sussex

[January Snowstorm]

Judging by your location in your avatar you're inland which will help if the channel low verifies. As for the 850's its inevitable that these will rise as the upper cold pool becomes exhausted. However there is a good surface cold pool to draw on,in mainland europe you can get snow off dam as much as 540. For the UK i'd say with the set up 536 might be okay. The actual trajectory of the low is quite favourable as its likely to draw a flow ahead of it from the east or se which will bring some drier air in and lower the dew point.

Well guys take note, js is about to be snowed in <_<

For all those who thought Ireland did badly in an Easterly, think again

By the way serious question, does anyone know how our sea temps are reacting to the cold spell????

This will be very important next week when onshore winds become strong

[sebastiaan1973]

temperatures for the De Bilt, based on the 12 run

9: -1/-5

10: +1/-1

11: 0/-1

12: -1/-2

13: +2/-3

14: +1/-1

15: +1/-3

16: -1/-4

17: -1/-4

18: -1/-4

[derrylynne]

Well guys take note, js is about to be snowed in

For all those who thought Ireland did badly in an Easterly, think again

By the way serious question, does anyone know how our sea temps are reacting to the cold spell????

This will be very important next week when onshore winds become strong

Sea temperatures have cooled a lot in this last week or so, now in single digits all around the coast. Generally 8C north sea to the north of the UK 6 to 7C southern half. Irish sea around 9C but cooler near coasts.

Will be interesting to see how this plays out. As the breakdown is forecast to be a way off yet on the charts it could be more of a trend that has been picked up and may not bring the warmer air in. As has been mentioned there were times in 1963 when warmer air tried to get in, hence the blizzards in the SW, but each time it was repelled and became colder again, often with days of sun and bitter temperatures. My hunch is that this cold spell may not be over. At the least it will probably bring a big snow event with it as there is such a lot of cold air over the Uk and being drawn off Europe...

[Candice]

NAE on Sunday shows less "blue" on the temps than I've seen for ages. How accurate are they temperaturewise@

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=nae&MODELLTYP=1&BASE=201001081200&VAR=tmp2&HH=48&ZOOM=0&ARCHIV=0&WMO=

[J10]

http://forum.netweather.tv/topic/60127-alps-forecast-10/

Latest Ski Blog out. Below are the daily runs from the GFS

Exploring the attack from the South West on the Tuesday Chart (T+96)

With a very cold surface feed from the SE, and Upper temps below zero, this cloud have heavy snowfalls for some south western areas, but details are very much still set to change before then.

[aspire27]

I think the models can be summed up by "chop and change"

Tomorrow things will probably change again, as the models have the last couple of days.

[Liam J]

ive been looking at the charts and noticed that we will be losing the 528 dam line, and saw some people mention as thay thought it may not snow....ive found this useful piece of info-

Thicknesses of 540 or lower indicate snow is most likely (50% of time a 540 thickness will produce snow at elevations below 1000 feet) and thickness values of greater than 540 most likely indicate non-snow precipitation. There are many circumstances in which a lower than 540 thickness can produce rain and a higher than 540 thickness can produce wintry precipitation. NEVER should a forecaster determine the precipitation type solely by the thickness value.

Edited January 8, 2010 by james12

[Rustynailer]

The irresistable force versus the immovable object; a battle royal :

http://www.wzkarten3.de/pics/Rtavn1141.png

Cold should win if it were 30 years ago, more often than not first time around the warm would not win.

Older members are bye and large urging caution with the west and the rain.

[reef]

New thread here: