A series of low-pressure systems will bring active weather across much of the U.S. this week. The first system will bring moderate to heavy snow from North Dakota into northern Minnesota Wednesday, with rain farther south. A second low develops over eastern Colorado and moves into the Midwest and Great Lakes late in the week, producing widespread rain across the Ohio Valley and northern Mid-Atlantic, and heavy inland snow across northern New England by Friday and Saturday. In the West, ongoing precipitation will taper in southern California, while a new system approaching the Pacific Northwest this weekend could bring rain and mountain snow. Temperatures start well above normal across the central US, with some highs in the 60s, before moderating closer to seasonal averages by the weekend.

Sunday: A slight risk of severe thunderstorms exists today across far southeast Alabama, southern Georgia, and the Florida Panhandle into north Florida. Widely scattered storms are possible, with damaging wind gusts and the potential for a brief tornado or two. This activity is associated with a fast-moving mid-level trough across the central Gulf Coast, pulling moisture northward ahead of a broken band of showers. Limited instability this morning will gradually increase through the late morning into early afternoon as surface temperatures rise and dewpoints climb into the upper 50s and lower 60s. The greatest threat for severe weather is expected late morning through mid-to-late afternoon as storms move east, with stronger winds and isolated tornadoes most likely near bows or small circulation features within the storm band.

Monday: A Marginal Risk of severe thunderstorms is expected Monday across parts of central and southern California, particularly south of Vandenberg AFB through the Los Angeles Basin and potentially into the Central Valley. Storms may produce damaging wind gusts and a couple of brief tornadoes. The threat is tied to a deepening low-pressure system off the California coast moving inland, combined with strong upper-level winds and cooling aloft, which will help lift moist air and create instability. Low-level winds may curve near the Transverse Ranges, enhancing rotation in some storms. Thunderstorms could begin late Monday morning along the coast and spread inland through the afternoon, with supercells possible in areas where instability and wind shear align, while the Central Valley may see a brief risk for isolated weak tornadoes.

Tuesday: Scattered thunderstorms are possible Tuesday into Tuesday night across California’s coastal areas and Central Valley, as well as parts of the mid Missouri Valley into the Upper Midwest, though the risk for severe storms remains low. In California, a weakening low-pressure system offshore combined with a strong upper-level jet will support scattered storm development, particularly across northern and central coastal areas and the Central Valley. Any stronger storms could produce small hail or gusty winds, but widespread severe activity is unlikely. Across the mid Missouri Valley and Upper Midwest, limited moisture and temperature differences may spark isolated thunderstorms capable of lightning Tuesday evening. Overall, while scattered storms are expected, conditions do not appear favorable for severe weather at this time.

Wednesday - Sunday: Medium-range guidance indicates that large-scale troughing will gradually move east from the Pacific Coast across the Rockies later this week into the weekend, with smaller disturbances embedded within the flow. This pattern may allow occasional surface low pressure development across the central Great Plains into the Great Lakes by Thursday. Limited moisture from the Gulf will support some isolated convection in the middle Mississippi Valley Thursday, with potential for increased storms Thursday night into the lower Ohio Valley, though any severe threat remains uncertain. By Friday into Saturday, moisture return may improve across the Ohio/Tennessee Valleys, southern Great Plains, and Ark-La-Tex region, supporting scattered thunderstorms along and ahead of a cold front. Overall, periodic storm development is possible, but widespread severe weather appears unlikely at this time.

National Weather Outlook sources: Weather Prediction Center & Storm Prediction Center