Radar upgrade improves accuracy

WILMINGTON, Ohio (WDTN) - When Tropical Storm Isaac moves through the Miami Valley this Labor Day weekend an improved radar will be tracking its rainfall. 

This is the most significant physical upgrade since the National Weather Service received Doppler radar back in the 1990's.   It's called dual polarization and is now ready to go in Wilmington.     

Conventional radar sends out one horizontal beam while dual polarization sends out two beams - one horizontal and one vertical.  Meteorologists can determine the shape and size of raindrops, hail and snowflakes.  But it will also help during heavy rain events. 

National Weather Service Meteorologist Allen Randall says, "This is going to be a great aid in our snow forecasting in the short term and our precipitation estimates.  I think that's where we're going to get our best improvement.  Flash flood warnings lead time on that b/c we don't have gages in every location so we greatly rely on our radar."

The upgraded radar will also be able to detect debris lifted in the air by tornadoes.  While this won't necessarily improve tornado warnings it will allow for higher confidence of the strength and track of a tornado.  

The upgrade went through its final testing phase today.   After Wilmington's installation half of the country's radars have been upgraded.

Click here to see graphics and a further explanation of the dual polarization upgrade.