NWS Seattle Briefings & Information

Powerful Pacific System Impacting the West; First Significant Snow for Portions of the East

Power Pacific system will continue to bring significant impacts for Pacific Northwest into northern California the remainder of the week. Dangerous coastal affects, heavy rain, flooding, strong winds, and higher elevation mountain snow continues. Meanwhile, a storm across the east is set to bring the first accumulating snow to many higher elevations of the Catskills into the central Appalachians. Read More >

Weather Risk Outlook

The Weather Risk Outlook colors are determined after NWS Seattle meteorologists examine both the impact level of potential weather scenarios AND the associated probability of those scenarios. The resulting outlook displays the highest risk for each day.

NWS Seattle meteorologists first use the impact table to determine the level of impact expected with a forecast weather event.

NWS Seattle meteorologists then determine the color by determining the probability of occurrence using all the available information and then reference the matrix to determine the risk level associated with the forecast weather event.