...There is a slight risk of severe thunderstorms over parts of the Northern Plains and Carolinas...
...Temperatures will be 10 to 15 degrees below average over the Pacific Northwest...
A strong upper level ridge will continue to dominate the weather pattern over the U.S. for the next several days. A storm system moving through the Pacific Northwest and Western Canada will be forced eastward across the northern tier of the U.S. Much below normal temperatures will be common across the Pacific Northwest in wake of the cold frontal passage today.
As the storm system moves into the Central U.S., active weather will be
confined to areas along and ahead of the occluded front and warm front in the Northern Plains and later the Great Lakes. Strong subsidence from the upper ridge should suppress shower activity in the Central Plains through the period even though a cold front will be approaching the region.
In the east, a frontal boundary will slowly drift southward from the Mid Atlantic to the Southeast. Showers and thunderstorms are expected along the boundary tonight from the Mid Atlantic to the Central Gulf Coast. By tomorrow scattered thunderstorm activity should be limited to coastal areas from the Carolinas to Texas.
In the Southwest, diurnally driven showers and thunderstorms are expected into the weekend. With a strong upper ridge in place to the east, tropical moisture will be drawn northward off the Eastern Pacific. Precipitable water values nearing two standard deviations above normal over the region will allow for isolated heavy rainfall and potentially flash flooding.