TAMDAR Discussion Board

TAMDAR data in Freezing Rain event

Posted By: Andrew Just
Date: 31-December-04 1244Z

Yesterday morning (December 30th) at the Marquette NWS office, we constantly looked at the latest TAMDAR soundings to get a measure of the amount of both dry air over the Western Great Lakes Region and how warm the air was aloft. The reason for this was the concern for a period of freezing rain across Upper Michigan, and whether some of the precipitation would start off as snow or sleet due to evaporative cooling. Surface observations told us when the freezing rain would transition over to rain, however the frequent soundings gave us more of an idea how long the freezing rain would last. Because the soundings showed potential for a couple of hours of freezing rain with little in the way of snow or sleet, we upgraded the winter weather advisories to ice storm warnings. These warnings would eventually verify during the afternoon, with reports of anywhere from 0.25 to 0.5 inch of ice along with plenty of accidents on the roads.