Interior New England Freezing Rain: 10-11 December 2012

Winter storm warnings have been issued for interior New England for a combination of snow, sleet, and freezing rain. Up to 0.5" of freezing rain may accumulate and cause some trees and power lines to fall. The following two images are NWS 6-h ice accumulation forecasts (issued the evening of 9 December 2012) for the area and they show a significant ice accretion threat across northern NY, most of VT, northern NH, and western ME.

Based on the synoptic-scale pattern across the Northeast from the 20121209/1200 GFS 36-h forecast valid this evening, 11 December 2012 0000 UTC, there is a threat for freezing rain observations across interior New England.  The highest probabilities are found across the higher elevations of NH and western ME precisely where the short-term forecasts have measurable ice occurring. These probabilities are based on having one observation report freezing rain for each analog.

Over the next month we will investigate adding a new product (ice storm probabilities) that would compliment this probability guidance. The ice storm probability product would highlight areas for prolonged freezing rain (e.g., Probability of 10 or more Freezing Rain Observations over a 24-h Period). A recent study of major ice storms in the Midwest suggests these storms are associated with 10 hours or more of freezing rain.