Chasing%20April%20Showers

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Chasing April Showers
WCD Friday 4th May, 2012 Thorwald SteinDYMECS
research assistant
Convective storms on Wednesday 11th April, 2012
Not by running around with your camera phone
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Chasing April Showers
This April is the wettest in the UK in records
which date back to 1910, according to early Met
Office figures to the 29th of the month.
http//www.metoffice.gov.uk/news/releases/archive/
2011/wettest-april-on-record
Other interesting facts for April 2012  Much of
the rainfall has been focused on the south of the
UK, with England seeing more rainfall than
Scotland.  Despite the heavy rain experienced
this month, sunshine amounts so far this month
have not been far off the average.
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Chasing April Showers
DYMECS Research questions

• How tall are these showers?
• How big are these showers?
• How much rain (or hail!) falls out?
• How do these showers evolve?
• And what did these showers look like in the
  forecast?

Scan them with the Chilbolton Advanced Meteorologi
cal Radar, the largest of itskind in the world!
http//www.stfc.ac.uk/Chilbolton/24821.aspx
DYMECS The Dynamical and Microphysical
Evolution of Convective Storms with Emilie
Carter, Carol Halliwell, Kirsty Hanley, Robin
Hogan, Humphrey Lean, Andy Macallan, John Nicol,
and Bob Plant
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Chasing April Showers
Will it be a good day for scanning
showers? Forecasts for Wednesday 11th April,
3pm,show it will be!
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Chasing April Showers
Tracking step 1

• Take 5-minute Nimrod rainfall radar data from
  MetOffice (1 km resolution)
• Label individual rainfall regions and store all
  its properties (location, speed, max rainfall,
  size)

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Chasing April Showers
Tracking step 2

• Score storms by relevant properties (bigger
  storms, heavier rainfall regions are interesting)
• Pick a small number of storms to prioritize and
  send commands to the Chilbolton radar

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Chasing April Showers
RHI (Range Height Indicator) scans through
convective cores show the heightof the storms.
Doppler velocity measurements can be used to
derive vertical velocities in the convective
updraft.
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Chasing April Showers
PPI (Plan Position Indicator) scans at different
elevations can be combinedinto 3D volumes.
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Chasing April Showers
PPI (Plan Position Indicator) scans at different
elevations can be combinedinto 3D
volumes. Several 3D volumes of the same storm can
be used to track its evolutionin size, peak
reflectivities, and height.
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Chasing April Showers

• Database of RHI and PPI scans for convective days
  
• Statistics on storm height, size, peak rain to
  evaluate forecast model
• Run model at higher resolution (Emilie Carter)
• or with different microphysics e.g. hail
  (Kirsty Hanley)

Visit our website! http//www.met.reading.ac.uk/d
ymecs Or read todays WCD blog!