Do The Met Office Know What Extreme Weather Really Looks Like?

By Paul Homewood

I have a prediction!

At the end of the year, the Met Office’s State of the Climate report will declare 2023 as a “Year of Extremes”.

It will highlight September as a particularly extreme month, with a heatwave (which peaked at temperatures several degrees lower than in 1906 and 1911); a monthly temperature no higher than in September 2006; and Storm Agnes.

I doubt whether anybody with any experience would find anything extreme about the weather last month. On the contrary, they will all be able to recall genuinely extreme autumn weather in the past.

For example, let;s look back to the 1960s, courtesy of Weatherweb:

Autumn 1960:

East Devon FLOODS, after repetitive HEAVY RAINFALL. Using data up to 2013, this was the third WETTEST autumn in the EWP data-set, with only 1852 and 2000 significantly wetter. July and August were also WET, as was the previous winter (see above). The combination of events led to FLOODS reported from many parts of the country come the autumn.

This actually barely begins to tell the story of just how catastrophic the floods were that autumn, particularly in Devon, which were some of the worst of the 20thC.

Devon Live has a very good account:

https://www.devonlive.com/news/devon-news/remembering-1960-floods-devastated-thousands-3137954

September 1961

Residual elements of the Atlantic hurricane ‘Debbie’ (presumably wrapped-up within a ‘standard’ mid-latitude cyclone) led to severe gales affecting ‘Atlantic’ Ireland, much of Scotland and the northern Isles. In the most intense phase on the 16th new records for strongest GUSTS occurred in Ireland, notably 93 knots at Shannon airport & 98 kn at Malin Head. Later in the day & early on the 17th, Lerwick Observatory (southern tip of Shetland) recorded a mean hourly WIND speed of 53 knots / 98 km/h, and a GUST of 77 knots / 142 km/hr, which at the time was the highest recorded since the Observatory opened in 1921. Severe dislocation of transport & electrical supplies in Ireland, with significant loss of woodland. Also, the deaths of at least 16 people. (GBWFF, HS/23)

Note the 93 kts (107 mph) recorded at Shannon Airport. Storm Agnes only got into the 30 mph range at low land sites.

November 1962

From the 8th, as winds came more from a continental (easterly) direction, TEMPERATURES fell steadily, then abruptly on the 11th as Russian/arctic air spread west. The following weekend (16th/17th) was one of the STORMIEST/MOST SNOWY on record for November. GALES were widespread, GUSTS of 75 knots being recorded on the Isles of Scilly on both the 16th and 17th, and SLEET/SNOW fell practically everywhere. Level SNOW was 7 inches (circa 17cm) deep in parts of Scotland, with DRIFTS of 3 feet (circa 1 metre), and roads were BLOCKED, traffic dislocated as far south as Devon, Cornwall & Somerset. COLD, northerly winds persisted for several days, with widespread FROST.

November 1965

Three (out of 8) cooling towers at the Ferrybridge power station near Doncaster (South Yorkshire) collapsed in very strong winds, and the five remaining towers were all damaged significantly. The nearest anemometer recording (about 12km / 7.5 miles away) produced a highest (60-minute) mean wind speed of around 40 kt / 45mph, and gusts were thought to be of the order 74 kt / 85 mph at the base of the towers. These values are not of themselves excessive either generally, or for the particular location, and the problem was not so much the wind strength, but that air was forced between one group of badly-sited towers in an enhanced way to the second (leeward of the first group), causing the collapse. Pre-construction tests (using a wind tunnel) had only considered an isolated tower, not the grouping planned; neither had gusts and local eddying (particularly possible lee-wave enhancement) been allowed for. It is now considered that the gust values at the tops of the towers were some 90 kt / just over 100mph.

While the winds were not exceptional we can  note that sustained wind speeds were recorded locally at 45 mph. more than double lowland measurements for Agnes.

October 1966

After weeks of persistent and often heavy rain, a spoil tip behind the village school in Aberfan, south Wales collapsed, burying the school under a torrent of slurry with the deaths of 144 people, 116 of the dead were school-children. After the ‘East Coast’ floods of 1953 (q.v.), this is now regarded as the second-worst natural disaster to affect the UK (in terms of deaths) since the Second World War.

September 1968

Prolonged HEAVY RAIN (enhanced by some long-lived THUNDERSTORMS forming in the vicinity of an occlusion across SE England, which in turn was associated with a slow-moving depression over northern France) on the 14th, 15th and 16th in 1968 caused WIDESPREAD & SEVERE FLOODING in the south east of England with 215mm falling at Northchapel (West Sussex) within 24 hours and 57mm in 42 minutes at Purleigh (Surrey). East Molesey in SW London .. near Hampton Court Palace was particularly badly affected. More generally, much of Essex, Surrey, Kent, and London recorded 150mm (locally 200mm) over these 2 to 3 days. Tilbury, Essex recorded 201 mm in two days – more than one-third of the normal annual fall. From mid-afternoon on the 15th, FLOODING over streams and rivers built up rapidly in Surrey, causing disruption to traffic and damage to property. One person was KILLED (a man died of a heart attack as he was swept away by flood-water). The widespread FLOODING took many days to subside – the impact was primarily due to the rapid/long-lasting nature of the intense RAINFALL (convective cells) – but was perhaps most unusual in that it affected such a large area of SE England. Newspapers of the time in Kent (e.g. ‘Kent Messenger’) stated that it was "the worst FLOODING since 1814".  The considerable / widespread FLOODING took many days to subside.

The late Philip Eden described them as “the most severe inland flood to hit the Home Counties in the last 100 years”

October 1969

And yes, there were even heatwaves!

One of the five DRIEST Octobers (17 mm) over England & Wales in the entire EWP series, and the 2nd DRIEST (after 1978) in the 20th century. Also, the equal 3rd WARMEST (equal with 2006, behind 2001 & 2005) October in the entire CET record.