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Snow criteria changes for winter storm watches, warnings

Winter Storm Watches/Warnings change

INDIANAPOLIS (WISH) — The National Weather Service has changed its heavy snow criteria for winter storm watches and warnings.

Previously, the heavy snowfall criteria were sectioned off, ranging from at least 6-8 inches of snow in 12- or 24-hour spans in central Indiana. The new heavy snow criteria in central Indiana will be at least 5 inches of snowfall during a winter storm event.

By changing the criteria, the National Weather Service is hoping to align Indiana climatology better with watches and warnings.

Not being tied to a timeframe will also allow for an improved approach to any event.

The heavy snow thresholds will differ depending on location. In northern Indiana, winter storm watches and warnings may be prompted for snowfall amounts 6 inches or more.

Meanwhile, in southern Indiana, the threshold will be 4 inches.

The threshold for other locations outside of Indiana have been posted online.

Map information courtesy of National Weather Service at Indianapolis

It is important to note that the criteria for a winter weather advisory remain untouched. Winter weather advisories for snow are usually issued when three to five inches of snow is possible.

Other hazards can still impact whether or not a winter storm watches and warnings are issued. Any combination of hazards, or the increased impact of a specific system can reduce the criteria for a winter storm watch or warning.

Recent winter storm warning data

Central Indiana’s most recent winter storm warning was for the heavy, wet snow that fell on Jan. 25. Looking back at the last 10 years, only two winters did not produce a single winter storm warning for central Indiana: 2017 and 2020.

Courtesy: Iowa State

Six of the last 10 years (2013-2022) have resulted in at least three winter storm warnings in central Indiana.

Be sure to stick with Storm Track 8 this winter. Find the latest weather blog at WISHTV.com.

Winter officially will begin on Dec. 21.