How Cold Mid-april Can Get

[Weather-history]

The pressure pattern for mid-April 1966 was extraordinary with a string of lows running from Newfoundland to Turkey and a large expanse of high pressure from northern Canada across Greenland into northern Scandinavia and through into the Arctic. Between these pressure systems was a flow with an easterly component that ran from Scandinavia through the UK into central Canada. This resulted in one of the coldest spells of weather for mid-April in recent times.

http://www.wetterzentrale.de/archive/ra/19...00119660412.gif

By the 13th, the easterly flow was becoming colder drawing in unusually cold Arctic air for the time of year from Scandinavia across the UK. Snow was reported falling widely and the intensity of the falls increased on the 15th as the air became increasingly cold and at this stage the snow was dry with maxima of 0C recorded in many areas and there was snow cover, the North Downs recorded several inches. Severe frosts were recorded in parts of Scotland, where minima as low as -10C was recorded.

Phil Eden's data for Hampstead Heath says it only recorded 1.9C as a maxima for the 15th of April

http://www.weather-uk.com/hampstead/years/Y1966.html

Although the intensity of the cold lessened after the 16th, it wasn't until the 22nd that it became noticeably milder as a low pushed up to the west of Ireland allowing a SWly flow across the UK.

Edited March 29, 2006 by Mr_Data

[Methuselah]

Oh dear! I think I can remember that...

[drfeelgood]

It looks like the mild or warm spell you described at the end resulted in a cold but unspectacular CET of 7.2. In fact, April 2001 was nearly as cold. It really shows CET averages can really mask cold and warm spells.

[Thundery wintry showers]

From the stats I have seen, the night minima would appear to have been largely responsible for keeping the mean temperature up- about what one would expect for a cloudy easterly month.

Other stats: April 1966 featured a maximum of just 3.9C at Durham on the 14th and there were maxima of 4-5C in Lancaster around midmonth. It was also one of the dullest on record in parts of eastern Britain.

[Terminal Moraine]

I've just had a look at my records for April 1966. I was recording at a site 140m lower than the current one and about 9 miles distant. The thermometer was not met' office standard but was reasonably accurate, it was also unscreened and mounted on a N facing wall. Unfortunately at that time I used to round up or down to the nearest whole degree F.

The max' temp' on the 14th, 15th and 18th was 36f (2.2c). and 7cm of snow fell on the 15th.

Maxima of this order would almost certainly imply freezing days at the current station, particularly as the wind was E/NE throughout the period. Freezing days so late in spring are very unusual even at this altitude so this really was an exceptional event.

Judging by similar events during winter at similar temperatures the snowfall here is likely to have been around 15-18cm.

T.M

[drfeelgood]

I'm not surprised by these stats as the 1960s was generally a very cool decade (also in a non-meteorological sense ) .

Note that no year in the 60s had a CET above 10C - it was almost as if the climate temporarily regressed back to the Little Ice Age. All seasons were distinctly cooler. However, apart from 62-63, no other winters were massively below normal.

I forgot to add that 1960s summers were particularly cool. 1969 was the warmest. If we had that kind of summer this year, it would be our coolest since 1993.

[Weather-history]

14th April 1966 maxima

RAF Upper Heyford: 0.2C

RAF Wethersfield: 3C

15th April 1966 maxima

RAF Bentwaters: 3.9C

RAF Lakenheath: 3.5C

RAF Mildenhall: 4.4C

RAF Woodbridge: 3.5C

[Nick H]

How about the cold of April 1983? I recorded a maximum of just 4C on April 18 that year. It was also the last notably cold Easter, with 6 inches of lying snow in the Chilterns on Easter Sunday morning, April 3.

My lowest April maximum was in 1989, just 3C on the 5th.

Edited April 10, 2007 by Nick H

[Weather-history]

 

[Bradowl]

Late April 1981 sticks out as being very wintry, Snowed for 3 days here in South Yorkshire with around a foot falling in hilly areas with snowdrifts several feet deep, temperature in Sheffield city center was only 1'c on the 23rd of April. 

Pictures from the sudden April blizzard of 1981 - Birmingham Live

WWW.BIRMINGHAMMAIL.CO.UK

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Wintry conditions hit in the middle of Spring nearly 41 years ago