Temperatures in many eastern regions of the UK dropped to -2C Saturday morning, making it the coldest September night for 32 years.
Brooms Barn, Cambridge NIAB, Monks Wood, Wittering, Weybourne and Woburn all recorded their coldest September night since 1986 — the solar minimum after cycle 21.
Dan Holley, from Norwich based forecasters Weatherquest, listed the temperature records on Twitter, adding, “It’s not very often we have nights this cold so early in the season.”
EAST – Coldest Sept night since…
Brooms Barn – 1986
Cambridge NIAB – 1986
Cromer – 2013
Houghton Hall – new record (opened 2001)
Marham – 2003
Monks Wood – 1986
Santon Downham – 2003
Weybourne – new record (opened 1986)
Wittering – 1986
Woburn – 1986
Elsewhere – 4 nights ago
— Dan Holley (@danholley_) September 29, 2018
The Winter of 1986/87
With the majority of this weekend’s lows coming close to September 1986 records, I thought I’d take at the look at the winter that followed.
And, lo-and-behold, the winter of 1986/87 turned out to be a teeth-chattering one with record snowfall.
In January, temperatures in southern England averaged 3.5C below normal.
On the 12th of January, the highest temperature in the UK was 0.1C, recorded at Butt of Lewis, Western Isles.
The 12th was also Hampstead’s (Greater London) coldest day since records began in 1909.
And the following day, the 13th, was the UK’s second coldest January day since 1947 (MetOffice). The lowest max temp on the 13th was -8.5C at Okehampton, Devon.
Heavy snow was also reported throughout the month.
The southwest recorded as much as 39cm in places, and Kent, in the southeast, witnessed 52cm, “the greatest depth of level snow in the area for at least 40 years” (MetOffice).
Strong and cold easterly winds combined with the heavy snow brought drifts of up to 6m high.
Solar variability plays a huge role in deciding our weather.
It’s no coincidence brutally cold temperatures and record snow totals often come at the depths of Solar Minima.
SOLAR VARIABILITY AND EUROPEAN WEATHER
Research shows blocking persistence increases when solar activity is low, causing weather patterns to become locked in place at high and intermediate latitudes for prolonged periods of time.
During a solar minimum, the jet stream’s usual Zonal Flow (a west–east direction) reverts to more of a Meridional Flow (a north-south direction) — this is exaggerated further during a Grand Solar Minimum.
Mikhaël Schwander, et al, 2017 — “The zonal flow characteristic of westerly types is reduced under low solar activity as the continental flow for easterly and northerly types is enhanced. This is also confirmed by the higher blocking frequency over Scandinavia under low solar activity.”
And the paper goes further:
“The 247-year-long analysis of the 11-year solar cycle impact on late winter European weather patterns suggests a reduction in the occurrence of westerly flow types linked to a reduced mean zonal flow under low solar activity. Based on this observational evidence, we estimate the probability to have cold conditions in winter over Europe to be higher under low solar activity than under high activity.”— Mikhaël Schwander, et al, 2017
With this being a Grand Solar Minimum we’re entering, we can expect the European winter of 2018/19 to be truly brutal, with record cold temperatures and snow accumulations.