...Slight risk of severe thunderstorm for a large area of the Central U.S.
...Flash flooding possible over portions of the Midwest through Monday...
...Cold and wet conditions expected over New England through Sunday...
A strong low-pressure system along the New England coast this afternoon is bringing widespread precipitation and anomalously cold temperatures to the Northeast. The low-pressure system is rather slow moving, so these cold and wet conditions are expected to continue through most of the weekend, particularly across northern New England.
At the higher elevations of the Northeast such as the Adirondacks in New York and the Green Mountains in Vermont, temperatures can be cold enough for snow to fall. Accumulating snow is possible, particularly at the higher peaks. The precipitation will slowly come to an end from south to north on Sunday, but will persist across northern Maine into Sunday evening.
Across the central U.S., a stationary frontal boundary will serve as a
focus for multiple rounds of showers and thunderstorms through the short range forecast period.
A complex of showers and thunderstorms is forecast to develop this evening across portions of the Dakotas and Iowa. This area of showers and thunderstorms will move southeastward along the north side of the front toward the Ohio River Valley by Sunday afternoon.
Another area of showers and thunderstorms will develop across the Northern plains/Upper Midwest Sunday night. There is a slight risk of excessive rainfall/flash flooding across much of the Midwest through Monday due to the potential for a few rounds of heavy rain and thunderstorms.
Farther south, moisture flowing northward from the Gulf of Mexico will interact with a dry line extending from Texas into the central High Plains to produce scattered thunderstorms each afternoon.
The threat for thunderstorms across the central and northern plains will increase further late Sunday into Monday as a storm system crossing the Rockies begins to exit into the Plains. There is a slight risk of severe thunderstorms across these areas. Please refer to the Convective Outlook products issued by the Storm Prediction Center for further information on the threat of severe weather.
Cool and unsettled weather will continue across portions of the Pacific Northwest and the northern Rockies as a series of upper disturbances move through a broad upper trough that is forecast to remain centered over the western U.S. through the early part of next week.
A weakening Pacific low-pressure system will move onshore in the Pacific Northwest this evening. The most widespread light to moderate rain will fall through tonight across coastal areas of Oregon and Washington, spreading into interior portions of the same states by Sunday afternoon. Scattered showers and thunderstorms will be possible across much of the northwestern U.S. as the pattern remains generally unsettled. A stronger Pacific storm system will approach the Northwest on Monday, bringing more widespread rain to the region again.