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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 more information, please refer to the following links: Product/Service Description Document, WSSI Fact Sheet, WSSI Infographic, WSSI Users Guide, Interactive ESRI Story Map, WSSI Future Work

*NEW* Rolling 24 HR WSSI 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.

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Download Latest WSSI in GIS Format:
Download Data in KML
Download Data in SHP

*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
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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. *Please Note* Static images only update at 01, 09, 13, 19 and 21 UTC