Graphical HWO - Winter Weather Threat

The winter threat categorical graphic shows the worst expected intensity of any wintry precipitation that may develop.

The probability of winter weather graphic reflects the probability of that winter weather occurring.

For example, if the categorical graphic is light orange, which depicts a "minor" threat, and the probability grid says "40", then there is a 40% probability of light accumulations (less than 1/2" of snow, or a trace of ice or sleet, as defined by the category's threshold).

Note to those familiar with the probability of precipitation concept: the winter weather probability graphic may or may not be identical to the normal PoP, which reflects the probability of any precipitation, not just wintry precipitation.

Winter Weather Threat - Categorical
Winter Weather Threat Graphic
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Categorical Thresholds
None No winter weather is expected during the period.
General A light mix of precipitation or flurries is expected. However, no accumulations or hazards to motorists are anticipated.
Minor Accumulations are expected to be very light (less than 1/2" of snow, or a trace of ice/sleet) and will be primarily a nuisance to motorists. Bridges, overpasses, and elevated highways may be susceptible to icing.
Moderate Moderate accumulations (< 1/10" of ice, < 2" of snow, or < 1/2" of sleet) are expected. Many roads will be slick and ice-covered. Motorists are urged to exercise extreme caution. Bridges, overpasses, and elevated highways will be especially hazardous.
High Significant accumulations of snow (> 2"), ice (> 0.25"), sleet (> 1/2"), or mixed precipitation are expected. Major highways will be snow or ice-covered and travel will be extremely hazardous. Secondary roads, along with bridges, overpasses, and elevated highways, will be virtually impassable. Scattered power outages are also likely.
Severe Severe winter storm anticipated with large accumulations of snow (> 4"), ice (> 0.25"), or mixed precipitation. Travel will be severely limited if not impossible. Power outages may also affect a significant portion of the area.

Probability of Winter Weather Occuring
Probability Graphic
Color Bar - 0 to 100%

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