New Experimental Winter Storm Warning Snowfall Criteria for the 2022-23 Winter Season

Beginning this winter season the National Weather Service Caribou Forecast Office will test a change to the Winter Storm Warning Snowfall Criteria in its County Warning Area of responsibility. The reason for the change is to better align warning snowfall criteria to the local climatology of the region.

Historically the National Weather Service Caribou County Warning Area snowfall criteria has been the following:

7 inches of snow in 12 hours or
10 inches of snow in 24 hours

The snowfall warning criteria was the same across the entire County Warning Area. This meant that the warning level snowfall criteria was the same in coastal areas and the interior mountains. There is a significant difference in annual snowfall amounts between these two geographic areas.

The new experimental criteria for this winter season will be based on local snowfall climatology to better align Winter Storm Warnings to what is normal for certain regions. Based on this approach it will limit over-warning in regions that are used to more snowfall. The experimental Winter Storm Warning snowfall criteria will be the following:

6 inches of snowfall during a winter storm event

Table with zone numbers and names for zones with 6+ inches of snowfall for warning criteria

Table 1: Universal Geographic Codes (UGC): Weather Zones included in the 6 inch Warning Snowfall Criteria

8 inches of snowfall during a winter storm event

Table with zone names and numbers for zones with 8+ inches of snowfall for warning criteria

Table 2: Universal Geographic Codes (UGC): Weather Zones included in the 8 inch Warning Snowfall Criteria

Map showing Northern Maine with 8+ inches of snow overlaid, and Central Maine and Downeast with 6+ inches of snow overlaid

There will be no changes to the Winter Weather Advisory snowfall criteria.

Evaluation of this experiment will take place in the spring of 2023 to determine if these changes will become official policy for the winter of 2023-24.

For any questions, please contact:

Louise Fode, Warning Coordination Meteorologist

Louise.Fode@noaa.gov, 207-492-0180 ext. 223

or

Patrick Maloit, Meteorologist in Charge

Patrick.maloit@noaa.gov, 207-492-0180 ext. 222