Weather across America

(NATIONAL) A Slight Risk of excessive rainfall over parts of the Great Basin, Freeze Warning and Frost Advisories over parts of the Northeast into the Great Lakes, and temperatures will be 10 to 15 degrees below average.

An upper-level low over the Mid-Atlantic will keep clouds and showers over the region through Tuesday. Moisture streaming inland off the Atlantic will produce rain that may be heavy at times over parts of the Mid-Atlantic. 

Therefore, the Weather Prediction Center has issued a Marginal Risk of excessive rainfall over parts of the Mid-Atlantic through Monday morning. The associated heavy rain will create localized areas of flash flooding, affecting areas that experience rapid runoff with heavy rain.

The threat of excessive rainfall continues on Monday with a Marginal Risk of excessive rainfall over the immediate Mid-Atlantic Coast, ending on Tuesday.

However, the clouds and rain will keep temperatures 10 to 15 degrees below average on Monday. In addition, strong high pressure over parts of Eastern Canada will provide clear skies and calm wind, allowing temperatures to cool off overnight, prompting Freeze Warning and Frost Advisories over parts of the Northeast into the Great Lakes late Sunday into Monday morning.

Meanwhile, a second upper-level low over the Northern Rockies will slowly drift to the Northern Plains by Tuesday. Moisture pooling over the Southwest and the upper-level energy will aid in producing heavy rain and thunderstorms over parts of the eastern Great Basin, Southwest, and Central/Southern Rockies. Therefore, the WPC has issued a Slight Risk of excessive rainfall over parts of the eastern Great Basin through Monday morning. 

The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, and burn scars the most vulnerable.

The threat of excessive rainfall decreases slightly on Monday over parts of the Southwest, Great Basin, and Central/Southern Rockies. Therefore, the WPC has issued a Marginal Risk of excessive rainfall over parts of the region from Monday into Tuesday morning. 

The associated heavy rain will create localized areas of flash flooding, affecting areas that experience rapid runoff and burn scars. On Tuesday, the Marginal Risk of excessive rainfall is limited to parts of the far eastern Southwest and parts of the Central/Southern Rockies.