Annex C
TIMELINE OF
ACTIVITIES PRIOR
TO 19-20 JULY
RAINFALL EVENT
Mon 16 July
Medium Range guidance indicated potential for
a heavy rainfall event on Fri 20 July but confidence was moderate.
Informal contact between the Met Office and the Environment Agency.
Tues 17 July
Potential for an extreme rainfall event across
England and Wales identified and discussed at Chiefs brief. Model
solutions remained variable but risk estimated as 40% based on
available evidence. EA informally notified of likely event.
Wed 18 July
NSWWS Early Warning for heavy rain issued at
1013BST, covering the period 0000 Fri 20 to 1200 Sat 21 July.
Potential for 60-90mm of rain mentioned but with uncertainly regarding
where highest totals would occur. Southern and eastern areas of
England considered most at risk (60%). Chief forecaster briefed
EA National Flood Warning Officers via audio conference in afternoon.
Thurs 19 July
Localised heavy downpours were covered by Flash
Warnings. Update to Early Warning issued at 1006BST, mentioned
this aspect before focusing on the more widespread heavy rain
for Fri/Sat. Potential for 75-100 mm of rain mentioned with focus
shifted towards southern and central parts of England and Wales.
Chief forecaster provided further brief to EA in afternoon, mentioning
totals exceeding 100 mm locally in high risk areas defined in
Early Warning. Excessive hourly totals (30-50 mm/hr) also highlighted.
Fri 20 July
Flash Warnings were issued for many southern/central
counties early in the day, with further issues/updates through
the day. Large hourly totals were mentioned in addition to longer
timescale accumulations. Highest hourly total recorded near Haywards
Heath late morning—42.8 mm. EA National Flood Warning Officer
was embedded in Met Office forecasting Operations Centre.
Sat 21 July
Localised Flash Warnings in force across SE
England and NE Scotland. EA national flood warning officer remained
embedded within Ops Centre during daytime hours.
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