Some models show the cold easterlies continuing through to late December (e.g. CFS graph left) but the GFS sees westerly Atlantic conditions (warmer) breaking through much earlier than that – end of next week infact – and warming things up for a “green” Christmas. As fronts from the Atlantic move in there is a high certainty of considerable snowfalls on the leading edge of any precipitation as the warm Atlantic air meets the frigid cold air sitting over the UK: next Friday 14 Dec could be the first of these snowy Atlantic incursions but that’s a long way ahead to be certain and Reigate may or may not see a big dump of snow as a result.
The Beast from the East – pussy cat or lion? The trend below from the 850hPa temperature forecast for London ECMWF shows a return to “normal” around next weekend (ignore the temperature scale). It is too early to say which models will turn out accurate but a white Christmas doesn’t look any more likely now just because of this cold snap: there are signs that warmer Atlantic conditions will return before the big day.
note: the abbreviations are for different computer forecast models commonly used for weather forecasting:
ECMWF = The European Centre for Medium-Range Weather Forecasts
GFS = Global Forecast System (NOAA)
CFS = Climate Forecast System