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 >

Hazard Map

Threat Levels

Safety & Impact

Graphical Hazardous Weather Outlook
Lightning Threat

The "Lightning Hazard Map" depicts the local threat of lightning for specified areas. It is largely based on the likelihood that cloud-to-ground lightning (CG) from thunderstorms will occur combined with the anticipated flash rate.

Lightning Threat Level	Threat Level Descriptions
Extreme	"An Extreme Threat to Life and Property from Lightning." Within 12 miles of a location, a moderate likelihood of CG lightning (or 50% thunderstorm probability), with storms capable of excessive CG lightning. AND/OR...a high likelihood of CG lightning (or 60% to 70% thunderstorm probability), with storms capable of frequent CG lightning. AND/OR...a very high likelihood of CG lightning (or 80% to 90% thunderstorm probability), with storms capable of occasional CG lightning.
High	"A High Threat to Life and Property from Lightning." Within 12 miles of a location, a low likelihood of CG lightning (or 30% to 40% thunderstorm probability), with storms capable of excessive CG lightning. AND/OR...a moderate likelihood of CG lightning (or 50% thunderstorm probability), with storms capable of frequent CG lightning. AND/OR...a high likelihood of CG lightning (or 60% to 70% thunderstorm probability), with storms capable of occasional CG lightning.
Moderate	"A Moderate Threat to Life and Property from Lightning." Within 12 miles of a location, a very low likelihood of CG lightning (or 10% to 20% thunderstorm probability), with storms capable of excessive CG lightning. AND/OR...a low likelihood of CG lightning (or 30% to 40% thunderstorm probability), with storms capable of frequent CG lightning. AND/OR...a moderate likelihood of CG lightning (or 50% thunderstorm probability), with storms capable of occasional CG lightning.
Low	"A Low Threat to Life and Property from Lightning." Within 12 miles of a location, a very low likelihood of CG lightning (or 10% to 20% thunderstorm probability), with storms capable of frequent CG lightning. AND/OR...a low likelihood of CG lightning (or 30% to 40% thunderstorm probability), with storms capable of occasional CG lightning.
Very Low	"A Very Low Threat to Life and Property from Lightning." Within 12 miles of a location, a very low likelihood of CG lightning (or 10% to 20% thunderstorm probability), with storms capable of occasional CG lightning.
Non-Threatening	"No Discernable Threat to Life and Property from Lightning." Within 12 miles of a location, environmental conditions do not support CG lightning.
Note: With cloud-to-ground (CG) lightning, every strike is potentially lethal. Occasional - CG lightning at the rate of 1 to 3 flashes per minute (about 5 to 15 flashes per 5 minutes) associated with a given lightning storm. Frequent - CG lightning at the rate of 4 to 11 flashes per minute (about 20 to 55 flashes per 5 minutes) associated with a given lightning storm. Excessive - CG lightning rate of 12 flashes or more per minute (about 60 flashes or more per 5 minutes) and is nearly continuous associated with a given lightning storm.

Determining Likelihood

Threat Awareness

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

Lightning Threats