Winter Model Discussion - Cold Hunting 08/01/13 00z Onwards

[Yarmy]

December 1990, you say?

http://www.ourmansfieldandarea.org.uk/images/uploaded/scaled/Mansfield_Snow_Mid_Dec_1990-18.jpg

[Thundery wintry showers]

Regarding snowfall, there is potential for a frontal snow-to-rain event on Sunday as fronts come down from the NW pushing into an accumulation of cold continental air. At present SE Scotland and NE England are looking most likely to see the white stuff at low levels, though it looks set to be pretty marginal:

http://cdn.nwstatic..../uksnowrisk.png

The preceding SE'ly looks likely to bring mainly rain or drizzle in off the North Sea during Friday and Saturday with temperatures around 3C.

The above event is prone to considerable uncertainty though as UKMO/ECMWF make a bit more of the preceding easterly (perhaps some snow showers near the east coast for a time) and delay the onset of the systems sliding down from the NW, which could mean a snow-to-rain event on Monday or Tuesday instead.

After that we have shortwaves sliding down from the NW. I do share many of Ian Brown's concerns, as the subsequent easterly blasts rely upon a build of pressure to our north and this is currently far from guaranteed- the ECMWF operational run does not show one and the ensemble mean is unconvnicning.

Edited January 8, 2013 by Thundery wintry showers

[mcweather]

The latter is the guidance I've been given (messy mix of rain, sleet, snow).

Incidentally - after an interesting conversation about where we may be heading, with my learned mentor this morning (!), he suggests take a look at Dec 1990 for what he considers a close analogy to what we have currently developing. He suggests I pull up the archives for this, but will do so when I get a moment.

Cheers

Ian

is that short term or long term Ian?

[karlos1983]

The latter is the guidance I've been given (messy mix of rain, sleet, snow).

Incidentally - after an interesting conversation about where we may be heading, with my learned mentor this morning (!), he suggests take a look at Dec 1990 for what he considers a close analogy to what we have currently developing. He suggests I pull up the archives for this, but will do so when I get a moment.

Cheers

Ian

compliments of Wikipedia

In the United Kingdom snow began to fall over the Midlands, Wales and the Pennines on the night of 7-8 December 1990 and continued for much of the following day. The rate of snowfall was quite heavy, around 6 centimetres (2.4 in) an hour, and as a result many areas were covered within half an hour of the snow starting to fall. Coupled with this were high winds which reached gale force in many areas leading to blizzard conditions. Many parts of the Midlands reported at least 20 centimetres (7.9 in) of snow while depths reached 60 centimetres (24 in) in the Derby area. On the Welsh Mountains there were drifts of up to 4 metres (13 ft). Snow fell in Western Europe the following day, 9 December.^[3]

If that's not a jinx i don't know what is

[Summer Sun]

The latter is the guidance I've been given (messy mix of rain, sleet, snow).

Incidentally - after an interesting conversation about where we may be heading, with my learned mentor this morning (!), he suggests take a look at Dec 1990 for what he considers a close analogy to what we have currently developing. He suggests I pull up the archives for this, but will do so when I get a moment.

Cheers

Ian

Some interesting charts from 1990

From this

To this in 4 days (8th December)

Edited January 8, 2013 by Gavin.

[Alexis]

Which suggests that based on 54 SSW events over the decades on average a SSW leads to warmer weather rather than cold

"From a total of 54 SSW events compared with 1940-2012 CET anomalies

1-20 days following SSW is 0.038°C warmer than the 20 days preceding SSW.

7-28 days following SSW is 0.116°C warmer

15-45 days following SSW is 0.089°C warmer."

Do SSW events in spring and summer lead to warmth though?

[fergieweather]

December 1990, you say?

http://www.ourmansfieldandarea.org.uk/images/uploaded/scaled/Mansfield_Snow_Mid_Dec_1990-18.jpg

8 Dec 1990 he tells me.

Also getting answer from MR guys on their view re GFS.

[Ian Brown]

The latter is the guidance I've been given (messy mix of rain, sleet, snow).

Incidentally - after an interesting conversation about where we may be heading, with my learned mentor this morning (!), he suggests take a look at Dec 1990 for what he considers a close analogy to what we have currently developing. He suggests I pull up the archives for this, but will do so when I get a moment.

Cheers

Ian

Thanks Ian, I’m sure you mean the general pattern of that month rather than the incredible snow event of the 8^th !

[Frosty.]

Not sure about the past disappointments comment, I'm pretty sure if there have been many disappointments in the past, there is pretty good reason for it!

What does that relate to SP?

I'm just relieved the recent ecm op runs are not currently favoured for next week, and tonights ecm 12z could be a lot better for longer term cold prospects.

[fergieweather]

Do SSW events in spring and summer lead to warmth though?

UKMO advise us 70% lead to colder.

[warrenb]

1990 scenario no good for down here, don't remember it as being anything interesting in Kent.

[High Altitude]

Have a look at this

Which suggests that based on 54 SSW events over the decades on average a SSW leads to warmer weather rather than cold

"From a total of 54 SSW events compared with 1940-2012 CET anomalies

1-20 days following SSW is 0.038°C warmer than the 20 days preceding SSW.

7-28 days following SSW is 0.116°C warmer

15-45 days following SSW is 0.089°C warmer."

Thanks Bobby.

I no this isn't the stat thread so just one final point mods if you don't mind.

Is it not more likely that a SSW event will help to reinforce and or strengthen existing areas of high pressure rather than develop them for example the Siberian high? This being the case could a SSW on its own not be enough and rather there needs to be developing or developed areas of high pressure in the right place at the right time to take advantage of this down welling and influence our weather on the ground.

[gottolovethisweather]

, as the subsequent easterly blasts rely upon a build of pressure to our north and this is currently far from guaranteed- the ECMWF operational run does not show one and the ensemble mean is unconvnicning.

TWS, in what timescale would we need this to occur and would a Scandi High be suitable?

[That ECM]

8 Dec 1990 he tells me.

Also getting answer from MR guys on their view re GFS.

I think your at the front of this roller coaster. So far today, after reading your posts, I have been through all the ups and downs. We have had leaning to EC, then battle ground, now the 8th of dec 1990!!!!!! Thanks for the imput. Time to get off the ride for a bit. Back on in 13 mins tho.

[kate1]

The latter is the guidance I've been given (messy mix of rain, sleet, snow).

Incidentally - after an interesting conversation about where we may be heading, with my learned mentor this morning (!), he suggests take a look at Dec 1990 for what he considers a close analogy to what we have currently developing. He suggests I pull up the archives for this, but will do so when I get a moment.

Cheers

Ian

8 Dec 1990 he tells me.

Also getting answer from MR guys on their view re GFS.

Thanks Ian, I’m sure you mean the general pattern of that month rather than the incredible snow event of the 8^th !

Apparently not!

[UV-RAY]

I think your at the front of this roller coaster. So far today, after reading your posts, I have been through all the ups and downs. We have had leaning to EC, then battle ground, now the 8th of dec 1990!!!!!! Thanks for the imput. Time to get off the ride for a bit. Back on in 13 mins tho.

Imagine the scenes at Exeter, lots of hair pulling and gnashing of teeth as each model run throws up a different scenario. Fascinating model viewing these last few days and a great learning curve for many of us. Edited January 8, 2013 by Sceptical Inquirer

[Frosty.]

The latter is the guidance I've been given (messy mix of rain, sleet, snow).

Incidentally - after an interesting conversation about where we may be heading, with my learned mentor this morning (!), he suggests take a look at Dec 1990 for what he considers a close analogy to what we have currently developing. He suggests I pull up the archives for this, but will do so when I get a moment.

Cheers

Ian

Hi Ian,

I dug out those archive charts you mentioned, I remember it well as we had a blizzard with drifting during that particular cold outbreak, fingers crossed for a repeat of that.

[UV-RAY]

Hi Ian,

I dug out those archive charts you mentioned, I remember it well as we had a blizzard with drifting during that particular cold outbreak, fingers crossed for a repeat of that.

We had cold rain Frosty, again! Edited January 8, 2013 by Sceptical Inquirer

[No Balls Like Snow Balls]

Imagine the scenes at Exeter, lots of hair pulling and gnashing of teeth as each model run throws up a different scenario. Fascinating model viewing these last few days and a great learning curve for many of us.

Apparently METO HQ in Exeter is split into 2 halves, the mild camp and the cold camp, quite often violence flares

[fergieweather]

I think your at the front of this roller coaster. So far today, after reading your posts, I have been through all the ups and downs. We have had leaning to EC, then battle ground, now the 8th of dec 1990!!!!!! Thanks for the imput. Time to get off the ride for a bit. Back on in 13 mins tho.

Battleground potential(s) has been about the single constant I've heard in any of the potential scenarios discussed thus-far....!

[Timmytour]

Mmmmm...Wasn't Dec 1990 about an event spreading east? (aside from not being south enough!) Me no likey!!!

[winterof79]

Imagine the scenes at Exeter, lots of hair pulling and gnashing of teeth as each model run throws up a different scenario. Fascinating model viewing these last few days and a great learning curve for many of us.

They will be fine

[Methuselah]

Can we please stick to what the MODELS are saying?

[Frosty.]

We had cold rain Frosty, again!

Better luck this time then SI.

[Weathizard]

We had cold rain Frosty, again!

Just spoke to my dad as I was a glint in his eye back then, was cold persistent rain while the rest of the country m4 north got plastered. Anyway let's us all pray to the weather gods the 12z sticks to its guns I have a bad feeling not though!