Snow Across the Great Lakes, Central Appalachians, and Northeast; Unsettled Weather in the West

Light to moderate snow will continue into Saturday over the Great Lakes, Central Appalachians, and Northeast. This weekend into next week, a series of atmospheric rivers will bring gusty winds, periods of heavy rain, and mountain snow to northern California and the Pacific Northwest. Colder temperatures are in store for the weekend from the Great Lakes to East Coast. Read More >

Graphical Hazardous Weather Outlook

Expression of "Likelihood"

Very High Likelihood	36% or greater
High Likelihood	26% to 35%
Moderate Likelihood	16% to 25%
Low Likelihood	6% to 15%
Very Low Likelihood	2% to 5%

Determining "Likelihood"

Likelihood = A x B
Confidence Factor	A-Value	Percent - Occurrence of hazard within a defined area
Slight	.1 or .2	10% to 20% confidence of occurrence
Slight to Medium	.3 or .4	30% to 40% confidence of occurrence
Medium	.5	50% confidence of occurrence
Medium to High	.6 or .7	60% or 70% confidence of occurrence
High	.8 or .9	80% or 90% confidence of occurrence
Coverage Factor	B-Value	Percent - Distribution of observations and/or reports within a defined area
Isolated	.1 or .2	across 10% to 20% of defined area
Isolated to Scattered	.3 or .4	across 30% to 40% of defined area
Scattered	.5	across 50% of defined area
Scattered to Widespread	.6 or .7	across 60% to 70% of defined area
Widespread	.8 or .9	across 80% to 90% of defined area

Threat Awareness

Snow Across the Great Lakes, Central Appalachians, and Northeast; Unsettled Weather in the West

Likelyhood