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Winter Forecast 2011/2012

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A Winter's Tale


[u][b][u]AWT FINAL WINTER FORECAST[/u][/b][/u]
[u][b][u]Winter 2011/2012[/u][/b][/u]

[u][u]Factors Involved:[/u][/u][list]
[*]Recent, Low Solar Activity - [color=#ff0000]NO IMPACT ON WINTER![/color]
[*]La Nina and a predicted strengthening La Nina - [color=#ff0000]DID THIS HAVE ANY IMPACT?[/color]
[*]The consitency of High Pressure over Greenland - [color=#ff0000]NO IMPACT ON WINTER![/color]
[*]Current and near future positioning of the jet stream - [color=#ff0000]NO IMPACT ON WINTER![/color]
[*]The Weather of the past 12 or so months - [color=#ff0000]DID THIS HAVE ANY IMPACT?[/color]


[b][u][u]DECEMBER 2011:[/u][/u][/b][list]
[*]The period 1st-7th December is likely to follow what should be a cooler end to November. I expect December to start off on a cooler note - than what November is likely to be as a whole - with nighttime frost and daytime temperatures of 4C to 9C. This period should bring a mixture of sunshine, cloud and fog to parts of the UK as settled weather prevails. The period should be dominated by low pressure systems with cool polar maritime incursisons following behind the fronts and bringing some wintry weather to parts of the North and West.
[color=#ff0000]Realitively accurate - Cool, low pressure, polar westerlies and wintry north west is accurate.[/color][list]
[*]During the period 7th-14th of December, I expect Low Pressure systems from the west to cross over the United Kingdom, bringing rain, wind, milder temperatures and some wet hill snow in the Highlands. Although temperatures are likely to be milder, I do expect some cool-cold polar maritime incursions between depressions bringing some sunshine (particulary to more southern and eastern areas although cloud may hang on to some coastal areas), some frost (perhpas lasting the entire day of some Northern areas) and wintery showers (most likely to be centered over NW Scotland and Northern Ireland).
[color=#ff0000]Quite accurate - Low pressure, milder, rain, wind, wet hill snow are accurate.[/color][list]
[*]What I see happening in the period 14th-21st of December is initially Atlantic Dominated before we see High Pressure in Atlantic link up With Higher Pressure in South-Eastern Greenland. The first few days will see a very active atlantic but still with the element of cold topplers behind the fronts and some of these may provide some snow to lower areas in England as some of the topplers will see more cold air than others. Towards the middle and into the latter part I expect to see the signs of Higher Pressure out in the Atlantic and Greenland building.
[color=#ff0000]Generally inaccurate - Intitially Atlantic dominated may be correct and snow for England was also correct for this period. There was a time that high pressure in the Atlnatic was perhaps going to link up with high pressure over Greenland (aka Simon Keeling) but it failed.[/color][list]
[*]The period 21st -31st December should start of quite unsettled and chilly initially. However as we head towards Christmas I expect the UK to enter a blocked period with a notable northerly spreading south over the UK during Christmas Eve and lasting till late on Boxing Day. An easterly attempt is broken down when Higher Pressure in the Atlantic and Greenland is smashed by strong areas of low pressure. However as we head towards towards the end of the period I expect a battleground snowfall to take place over the UK and perhaps leading to some large accumilations in the Northern Half of the UK. Following the snowfall, there should be a thaw, and a return to less cold conditions with incoming low pressure systems.
[color=#ff0000]Very Inaccurate - Nothing correct about this and really the final outcome was the opposite to my forecast. [/color]

[b][u][u]JANUARY 2012:[/u][/u][/b][list]
[*]The New Year should start pretty chilly with snow snow in the NW of Scotland as chilly zonal pattern prevails with some cold topplers. One or two of these topplers could bring some pretty expansive cold air over the UK and the potential threat for some more frontal snowfalls. During this period I expect signs of a warming in the Stratoshphere (perhaps since Christmas).
[color=#ff0000]Not wrong but not correct - The New Year did start off zonal but really there was little snow nor sign of a SSW[/color][list]
[*]The duration of the 7th-13th of January should see indications of High Pressure Building over Greenland and vague hints of a pressure rise in NE Scandinavia but the period should should be predominatley Atlantic dominated although the jet stream should gradually be moving south and extremes of pretty mild sectors to cold sectors will be felt.
[*]The Period 13th-20th January should see High Pressure over Greenland firmly established and more profound than the attempt of Northern Blocking in late December. Initially, the UK Should be pretty chilly, but as very intense cold air from the Arctic comes down in a notable northerly, we should quickly see things turn progressively and substantially colder. By the middle of the period I would expect some pretty heavy snow showers in Shetland and Northern Scotland aswell as NI with night time temperatures widely below freezing and droping to below -10C in the Highlands. However by the end of the period, I would expect some notable and prolonged periods of snowfalls crossing south over Scotland before intensifying over England, Wales and Ireland over the Irish and North Sea. By the end of the period, -15C or lower should have been reached in the Scottish Highlands.
[*]Between the 20th and 27th of January, I expect to see a gradual increase in terms of intensity of cold and snow with temperatures of -15C to -20C being reached in the Scottish Highlands throughout the period so really not too much of a change in that area but daytime temperatures and night time temperatures elsewhere should be colder at the end than at the beginning. With conitinuos snow showers in the North and some going further south down eastern and western coasts, there shouldn't be too much of a problem with snow in this cold but quite quiet period of weather. However towards the end of the period, as the Greenland High shows signs of a decline, the potential for heights over Scandinavia increase.
[*]The time frame of the 27th - 31st January should be quite active. The start of the period should see temperatures drop lower than that in the first period with some temperatures in the Highlands below -20C and in some cities -10C should have been reached. As winds have a slight NWly element in them, snow showers should become more expansive and prolonged in North and much of the west. However as Heights over Greenland start to dissolve we should see an incoming aprroch of fronts to create an incredibly messy breakdown. However as the fronts head towards the UK and Ireland, I expect heights over Scandinavia to build.
[color=#ff0000]Not 100% wrong[/color]

[b][u][u]FEBUARY 2012:[/u][/u][/b][list]
[*]The period 1st-7th of Febuary is expected to see an incredible battle between the milder Atlantic and a very strong and expansive area of High Pressure over Scandinavia. Initially, we should see some impressive snowfalls as milder Atlantic air meets colder Arctic air, however the front(s) are expected to stall over Central and Eastern parts of the UK contributing to some very large snowfalls. In the western edge of the front it should be slightly less cold as the front over the Eastern half of the country dissolves leaving behind small pockets of light snow and some large snow depths. As the front fails to win, the easterly wind locked and trapped by the front is unleashed bringing impressive cold temperatures to all parts of the UK and widespread, heavy, convective snow showers and streamers all the way from Kent to Wick. Eastern and some central parts of England and Scotland should see some very impressive snowfalls and decent depths. In parts of Ireland and southern Wales there may be some impressive snowfalls from streamers and Western Scotland should experiences some snow showers from any streamers. In the eastern Highlands, temperatures of -15 to -25C are possible and in some eastern and northern towns and cities, temperatures of -10 to -20C are possible.
[color=#ff0000]Not right but not wrong[/color][list]
[*]The following period of the 7th-14th of Febuary is expected to see the High Pressure over Scandinavia and the Easterly winds to continue. The beginning and ending of the period is likely to see the worst of the snow for much of the east coast and some more prolonged areas of snowfall spreading further inland into more Central and Western areas right up and down the UK. But essentially, the main aspect of the period is the temperatures during the middle with temperatures in Cities such as Aberdeen, Edinburgh and Glashow droping to below -15C and -10C being reached in cities further south including London. Snow showers won't be quite as profound, although there will still be some light snow showers in eastern coasts and filtering their way along the Channel, Thames Valley, Central Belt and Midlands. In the Highlands temperatures of -20C are more than likely.
[color=#ff0000]Not right[/color][list]
[*]The period 14th-21st of Febuary should see the cold continuing during the early stages. However the high pressure over Scandanavia will begin to show signs of fading and this should result in another messy breakdown. The first few days may see some record breaking temperatures and snowfall should increase. However low pressure systems should be able to come near or cross the UK bringing the threat of very large battleground snowfalls in the West. However in the east, there could be asmuch as a 10C difference with an easterly influence and some snow showers. Eventually, each front should gradually creep further east across the UK with precipiation in the far west falling as rain in milder temperatures and very heavy snow falling for anywhere further east. In far eastern areas, the temperatures will be at their lowest and 10C lower than that of the rest of the UK. Once the Atlantic eventually wins, temperatures in the North and East may still be slightly below average and in the south and west it will be slightly milder.
[color=#ff0000]Not right but not wrong[/color][list]
[*]The month should end under with a milder Atlantic influence with some very mild temperatures in the South West, however further North and East, and particulary Scotland it will feel, much, much cooler in cool-cold zonality and still further prospects of wintry weather.


CET Values:

December (4.5C), January (1.7C), February (1.6C) = Overall a below average winter.

That's my Final update for the winter forecast and the one that I'm most happy with.
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