Improved Thunderstorm Detection, Tracking and Assessment Products for Environment Canada Radars Presented by Pat McCarthy Prairie and Arctic Storm Prediction Centre Meteorological Service of Canada (MSC) David Patrick (Lead Author) Hydrometeorological and Arctic Lab MSC

THE CHALLENGE FOR FORECASTERS: Handling a big area, many radars, yet be able To drill down to the storm scale

Canadian Radar and CARDS 31 C-Band Doppler radars nationally 24 conventional data tilt strategy 4 Doppler scans Many basic conventional and Doppler products (URP) CAnadian Radar Decision Support (CARDS) system Similar to WDSS sophisticated product suite Primarily designed for severe thunderstorms Lots of promise but room for improvement HAL and PASPC exploring ways to enhance CARDS

Quick URP/ CARDS overview

Multi-radar view

Cell-view window

Making it better Radar processing has traditionally been done in isolation from other weather data But forecasters integrate all datasets when developing a diagnosis URP was designed to be able to access other data sources such as model data and lightning It’s time to move to the next level and develop algorithms that take advantage of these multiple data sources …

BWER Calculate BWER volume (km^3) as well as BWER height Old BWER Looked at only 5 directions in upward direction instead of 9 Didn’t require a vertical bound Didn’t give partial credit for gradients < 8 dBZ/bin Had a bug that disallowed BWERs north of radar Ran 10 times slower than new BWER.

How do you know if a BWER is real? Use 3D viewer

Zooming out we can see that lots of cells of various intensities are tracked simultaneously The 2 large boxes represent 2 tornadic supercells

New Rank Weight Old Rank Weight (from 2006) SCIT = Storm Cell Identification Table New Rank Weight Old Rank Weight (from 2006)

New CELL View Geographic Background (towns & roads) Observed Storm-relative radial velocities

(Velocity Azimuth Display) Old CARDS VAD (Velocity Azimuth Display)

New VAD

Vertical Cross-Section T -50, -40, -30, -20, -10, 0 C contours plotted Tw 0, 2, 5 contours plotted

Storm-relative Radial Velocity using user-defined storm 257/60 km/h Storm motion shown here

COnstantTemperaturePPI Access model GRIB data to create any temperature, dewpoint or wetbulb temperature surface Plot radar echoes on this surface.

50+ dBZ and 20 mm hail over South Winnipeg Radar echoes at -50C 50+ dBZ and 20 mm hail over South Winnipeg

Summary These and many other products are being tested by the PASPC The more robust products will migrate to operational CARDS nationally Demonstrates the power of integrating multiple datasets Many other products being designed

Thank you