Chasing April Showers

Convective storms on Wednesday 11th April, 2012

WCD Friday 4th May, 2012Thorwald Stein

DYMECS research assistant

*Not by running around with your camera phone

“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.”

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.

http://www.metoffice.gov.uk/news/releases/archive/2011/wettest-april-on-record

Chasing April Showers

Chasing April Showers

• 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 AdvancedMeteorological Radar, the largest* of itskind in the world!

DYMECS Research questions

* http://www.stfc.ac.uk/Chilbolton/24821.aspx

DYMECS – The Dynamical and Microphysical Evolution of Convective Stormswith Emilie Carter, Carol Halliwell, Kirsty Hanley, Robin Hogan, Humphrey Lean,Andy Macallan, John Nicol, and Bob Plant

Chasing April Showers

Will it be a good day for scanning showers?Forecasts for Wednesday 11th April, 3pm,show it will be!

Chasing April Showers

• 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)

Tracking step 1:

Chasing April Showers

• 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

Tracking step 2:

Chasing April ShowersRHI (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.

Chasing April Showers

PPI (Plan Position Indicator) scans at different elevations can be combinedinto 3D volumes.

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.

Chasing April Showers

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/~dymecs

Or read today’s WCD blog!