"Chris" wrote ...
Looking at the 1km radar:
Main band of rain encroaches upon the western tip of Cornwall ~18:00
on the 16th, reaching St Austell Bay at ~20:00. Most of the rain
rates are 5mm/hr, but a few heavier regions ~10mm/hr.
After 21:00 a stronger line of rainfall (10m/hr) appears aligned
NNW-SSE through Penzance, moving eastwards through Falmouth ~22:00.
Although this line dissipated somewhat as it moved over St Austell,
there was orographic enhancement over Bodmin Moor over the next 2-3
hours. Meanwhile out to the west a thin line (5km E-W) of very
heavy rain (50mm/hr) developed. This line first appears fragmented,
but started to form a continuous line from northern Cornwall,
southwards across the Lizard and out into the channel at ~03:00 on
the 17th. This line then develops slightly to the east of the
Lizard, so that by 04:00 it stretches from St Austell,
south-westwards just to the East of the Lizard. On the southeast
side of this line (about 50km out over the channel) there appears to
a much drier region being dragged northwards. The thin line of heavy
rain then wriggles north-eastwards, decaying over the next 3-4
hours.
Given the thinness of the heavy rainfall area I suspect it would
have missed many of the gauge locations: maximum rainfall
accumulations based upon the radar suggest in excess of 50mm in a
band no more than 4-5km wide; 35 sq kilometres with 75mm total over
Bodmin Moor, and ~ 13 sq kilometres with
75mm on the St Austell area.
.... Thanks very much for all that information Chris; interesting to
see the output from Restormel EA river monitoring gauge (R. Fowey)
he-
http://www.environment-agency.gov.uk...stationId=3152
a sharp increase in the short period after 17/0600 NOV, which suggests
that an awful lot of rain had fallen in the hours preceding upstream
of this point - threatening the 'highest recorded' value since the
station opened in 1961. There will no doubt be EA gauges co-located
with the sensing point, so we'll get a better idea of spatial rain
totals in due course - however, as you point out, getting a 'true'
total rainfall is always problematical.
Martin.
--
Martin Rowley
West Moors, East Dorset (UK): 17m (56ft) amsl
Lat: 50.82N Long: 01.88W
NGR: SU 082 023