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Winter Storm Severity Index (WSSI)
The WSSI does not depict official warnings and should always be used in context with official NWS forecasts and warnings. For a users guide and more information about the WSSI, please select from the dropdown menu below.

*NEW* Rolling 24 HR WSSI Display located here
Probabilistic WSSI (WSSI-P) Display Located here

Overall Impact: Maximum impact from any of the components.

Snow Amount: Potential impact from snow amount and snow rate.

Snow Load: Potential impact from the weight of snow on structures.

Ice Accumulation: Potential impact from the ice accumulation and wind.

Flash Freeze: Potential impact from rapid decreases in temperature from above to below freezing with the presence of liquid water.

Blowing Snow: Potential impact from falling snow combined with wind.

Ground Blizzard: Potential impact from snow on the ground combined with wind.

Select Zoom Area:

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Download Latest WSSI in GIS Format:
Download Data in KML
Download Data in SHP
REST Service Links

*NEW* WSSI Static Image Archive:
WSSI Static Image Archive Data

Map Overlays
NWS County Warning Areas River Forecast Center Boundaries
FEMA Boundaries Counties Boundaries
State Boundaries NWS Public Forecast Zones
Urban Areas ARTCC/FIR
Retrieve Static Images
Select Zoom Area
Select WSSI Element
WSSI Overall Blowing Snow Flash Freeze Ground Blizzard
Ice Accumulation Snow Amount Snow Load

To retrieve static images please select a zoom area and WSSI element.