November 1993 contained an easterly spell for the UK and Ireland which brought widely the first of what was to become a fairly decent season for snow including the first November snowfall since 1980 to fall in southern regions of the UK. When 2010's November snowfall is talked about, climatologists and weather historians compare it as the earliest widespread snowfalls in the season since November 1993 although late October 2008 had widespread snowfalls even as far south in the UK as London. A large anticyclone with a central pressure of 1052hPa by the 20th over Finland built over Scandinavia during the middle of November 1993. This massive blocking area of high pressure blocked off Atlantic rainbelts from pushing across Ireland and the UK. As a result, cold continental air pushed in from Europe to the UK and Ireland. This forced air and ground temperatures to drop below average with some notable widespread frost for a time but fronts attempted to attack from the 23rd-25th before high pressure from Scandinavia extended westwards again on the 26th but that was pretty much the spell. It was short but sweet with some early snowfalls and very cold temperatures. It was the last November to have a CET under 5.0c (up to 2017) with a mean of 4.6c.
Some snowfall figures during November 1993 easterly:
Dublin Airport; wintry showers on the 22nd and 23rd
Charing, Kent; 7cm accumulation on the 21st
Inchmarlo, Grampian; 17cm accumulation on the 22nd
Inchmarlo, Grampian; 19cm snow depth on the 23rd
Inchmarlo, Grampian; 20cm snow depth on the 24th
These figures weren't significant especially in comparison to November 2010's (and November 1919, 1952) snowfalls but they were notable for their time and how early they took place. However, people's recollections of the November 1993 easterly spell say that the snowfalls were constant to the east of the UK near the North Sea with the snow staying for over a week on the ground. I never thought of November 1993 being as an exceptional month but some of these figures I've taken a gander at are something else for November.
Daily extremes for the spell in the UK
Friday 19th
Lowest maximum: 1.3c at Finningley near Doncaster
Lowest minimum: -5.9c at Shap, Cumbria
Lowest grass minimum: -11.3c at Shap, Cumbria
Saturday 20th
Lowest maximum: 0.1c at Strathallan, Tayside
Lowest minimum: -8.7c at Edinburgh, Scotland
Lowest grass minimum: -12.6c at Shap, Cumbria
Sunday 21st
Lowest maximum: -1.1c at Stansted, Essex (really impressive for that part of the UK in November)
Lowest minimum: -6.0c at Bastreet, Cornwall (really unusual to see the lowest minimum in the southwest of the UK)
Lowest grass minimum: -11.3c at Beaufort Park, Berkshire
Monday 22nd
Lowest maximum: -2.0c at Glenlivet, Grampian
Lowest minimum: -10.5c at Aviemore, Highland
Lowest grass minimum: -14.3c at Aviemore, Highland
Tuesday 23rd
Lowest maximum: -5.3c at Aviemore, Highland
Lowest minimum: -10.4c at Strathallen, Tayside
Lowest grass minimum: -14.6c at Aviemore, Highland
Wednesday 24th
Lowest maximum: -5.4c at Aboyne, Grampian (Braemar's afternoon high was -8c on this day)
Lowest minimum: -14.8c at Grantown-on-Spey and Braemar (lowest in the UK since February 1991 and lowest for November since 1985)
Lowest grass minimum: -17.6c at Aviemore, Highland
Thursday 25th
Lowest maximum: 1.0c at Strathallen, Tayside
Lowest minimum: -8.0c at Loch Glascarnoch, Northwest Scotland
Lowest grass minimum: -11.9c at Kinloss, Moray Firth
Friday 26th
Lowest maximum: -1.1c at Strathallen, Tayside
Lowest minimum: -6.8c at Strathallen, Tayside
Lowest grass minimum: -10.9c at Belfast, Northern Ireland
That minimum of -6.0c at Bastreet, Cornwall on Sunday 21st November 1993 really was highly unusual to see cold like that in the southwestern quarter of the UK at any time of year especially outside of Winter. It was beaten just two days later by an even more unusually low minimum for the place with -9c which was its lowest for November on record.
In Ireland, the lowest air temperature was -6.9c at Mullingar, Co. Westmeath on the 22nd whilst Derrygreenagh, Co. Offaly had a grass minimum of -15.7c that same night. These were the lowest November temperatures for Ireland since 1988 though of course 2010 smashed these. Low maximums:
Dublin Airport; 4.2c on the 22nd
Casement Aerodrome; 3.6c on the 22nd
Mullingar; 3.9c on the 22nd, 4.3c on the 23rd and 4.9c on the 24th
Oak Park; 4.0c on the 22nd
Mean sea level pressure over Russia near Moscow during November 1993 was over 1040mb which is around 20hPa above normal! That was a real classic of a Siberian High.
Commentaires