Weather Talk: Dual-Pol can ‘see’ things traditional Dopper can’t
FARGO – You might have seen a WDAY weather promotion on television talking about how we use the Dual-Pol Doppler technology.
The promotion, however, does not get into what this thing is. Dual-Pol is short for Dual-Polarity Doppler.
The National Weather Service Doppler system, including the one at Mayville, N.D., now sends out two Doppler pulses oriented perpendicularly.
This allows a set of computer algorithms to make some assumptions about the shapes of the objects it “sees.”
One key advantage we used extensively a week ago is the ability to discern between snowflakes and raindrops. Traditional Doppler could not do that. Another function is the ability to detect storm debris as a way of confirming if a tornado is actually causing damage.
Both of these functions are limited by the fact that the Doppler beam is at a certain height above the ground and cannot always “see” what is actually right at ground level.