Weather across America

(NATIONAL) Heavy rain and severe weather to impact portions of the southern and central Plains, below-average temperatures continue across the West, precipitation chances across much of the Northwest, and dry conditions come to an end as thunderstorms enter the East.  

An unsettled weather pattern is expected to continue across the central U.S. with strong to severe thunderstorms in the short-term forecast. Persistent upper-level ridging combined with warm, moist southerly flow at the surface are both helping to enhance instability across the region.

As a result, strong to severe thunderstorms are expected to continue. An Enhanced Risk of severe weather (level 3/5) was in effect for portions of the Upper-Mississippi Valley on Sunday, with the primary threats being severe wind and large hail. Additionally, a Slight Risk of severe weather (level 2/5) is in effect for portions of north-central Texas and southwestern Oklahoma, as strong thunderstorms are expected to initiate off of a strong dryline draped across the region. The primary threat with these storms will be severe wind gusts. This weather pattern is expected to continue into early next week. 

On Monday and Tuesday, there are Slight Risks of severe weather in effect over the Mid-Mississippi Valley, with the primary threats bring severe wind and isolated regions of large hail. Heavy rain and flooding are possible within these thunderstorms, especially given high rainfall rates and the potential for training thunderstorms. A Slight Risk of Excessive Rainfall (level 2/4) has been issued over portions of eastern Iowa and western Illinois. Temperatures will vary significantly based on thunderstorm activity, but the overall weather pattern supports above-average high temperatures for much of the central U.S. Most highs in the mid-to-upper 80s during the early-week across the region, which is 10-20F above average.

In the West, temperatures will continue to be well below-average to start out this week as an amplified upper-level troughing pattern persists over the region. On Sunday, temperatures across much of California, Oregon, and portions of the Intermountain West were 10-15F below average. High temperatures were only in the mid to upper 50s in the Intermountain West, with 60s & 70s across northern and central California. In addition to below-average temperatures, there are precipitation chances across much of the Pacific Northwest. Some of this precipitation may fall as snow, particularly in the higher elevations of northern California, Oregon, Idaho, western Montana, and western Wyoming.

In the East, dry conditions will come to an end as a warm front approaches the region, helping to initiate scattered showers and thunderstorms. The precipitation band entered portions of the north-central Appalachians on Sunday afternoon, and into the areas toward the Mid-Atlantic by Sunday night. While many of these thunderstorms will be non-severe, a Marginal Risk for severe weather (level 1/5) extended from the central U.S. into the Ohio Valley/central Appalachians on Sunday, with the primary threat being severe wind gusts. 

Stormy conditions are expected to continue into early next week, especially during daylight hours, as a cold front progresses through the region. A brief wave of cool temperatures are expected in a localized region encompassing the coastal Northeast and Mid-Atlantic this week following a cold frontal passage, with highs expected to be in the 60s early this week across the region.