National Weather Service United States Department of Commerce

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 >

"Bolt From the Blue"

Photograph and LDAR images (below) 

This is a classic example of a 'Bolt from the Blue". Note how the flash eminates from about 2/3rds the way up from the updraft, travels a relatively large distance horizontally away from the storm and then angles down towards the ground. If a person was nearby where this flash hit the ground, that person would be extremely startled as the storm (and the heavy rain) is many miles away from where the flash made contact with the ground.

The image below is what a bolt from the blue looks like on LDAR:

Note how this flash travelled to the east 40 KILOMETERS away from where the storm was located! (note distance on X axis in upper left box). This flash struck very close to the National Weather Service Office here in Melbourne. The storm itself was located in northeastern Osceola county (Florida).

Here is another Bolt from the Blue which occurred near the Kennedy Space Center. This flash is overlayed on radar data which was collected near the time of the flash. Note how the flash travels away from the radar reflectivity.

Bolts from the blue are obviously very dangerous to the general public as they can strike many miles away from the storm.