Page 23 - June 2024 Newsletter

measured 40 mph gusts on 9 April and 17 mm of rain on 28 April.
The sea-level atmospheric pressure rose to 1025 hPa on the 21st,
falling to 975 hPa towards the end of the month. The average
pressure was 1005 hPa. Winds were mainly from a westerly
direction but turned easterly at the end of the month.
Despite the rain
and cloud there
were only three days
without any
sunshine and a total
for the month of 109
hours, which is
33 percent below
the average for April.
This was 30 hours
fewer than April 2023.
When is a storm not a storm?
There seem to have been rather a lot of named storms over
the past few months, with two alone mentioned above. The
legal definition defines a storm as being a high wind [1]. The
Royal Meteorological Society [2] says it’s a weather system
accompanied by strong winds and other destructive weather
such as heavy rain, thunderstorms and/or hail. The Shipping
Forecast defines storm force winds as having a mean wind
speed of 55-63 mph over a ten-minute period or gusts to 70-
78 mph. The Association of British Insurers states a storm
should have winds gusting 55 mph, or torrential rainfall of a
least 25 mm per hour, or rates of snowfall to at least 12
inches deep in 24 hours, or hail with a force to damage hard
surfaces or break glass. Finally, the Met Office states a storm
is a violent atmospheric disturbance, which may include
fierce winds, thunderstorms, squalls, snow storms,
hailstorms, etc. But what if you experience a violent
atmospheric disturbance that causes damage necessitating
an insurance claim and the Met Office has not declared it as a

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