Severe thunderstorms and flash flooding are of concern across portions of the Central and Southern Plains, as well as the Mississippi Valley today.
In the Central CONUS, shortwave disturbances originating from a mid-level trough anchored over the northern tier will trigger scattered to isolated thunderstorms across the Plains and Mississippi Valley. Some of these storms, particularly in north-central Texas, could escalate to severe levels, prompting a Slight Risk of Severe Thunderstorms as designated by the Storm Prediction Center. Given recent heavy rainfall in certain areas, there’s an increased risk of flash flooding, particularly in southeastern Texas, where a Moderate Risk of Excessive Rainfall has been identified.
As we progress into Friday, the primary threat of severe weather and excessive rainfall will shift towards the Ohio/Tennessee Valley and Lower Great Lakes regions as associated low pressure systems move eastward. Another round of showers and thunderstorms is expected as a second cold front sweeps through the Great Plains.
Meanwhile, in the Northwest, an upper trough is leading to below-average temperatures across the northern tier, supporting high elevation snow across the western mountains, notably the Northern Rockies. Significant snowfall accumulation, ranging from 6 to 12 inches, is anticipated by Saturday morning. On Friday night, a new low pressure system emerging over the Pacific Northwest will bring moisture for low elevation rain and mountain snow.
Conversely, an upper-level ridge downstream of approaching shortwave impulses will usher in well above-average temperatures from the Ohio Valley to the East Coast today and Friday. Some areas within these regions may even break or tie high temperature records. A Moderate Heat Risk is in effect over portions of the Mid-Atlantic today, particularly impacting heat-sensitive individuals lacking adequate cooling and hydration. Temperatures will gradually decrease heading into the weekend after a cold front moves through.