Weekly Weather Watch: Wednesday, May 21st, 2025
A dynamic weather pattern continues this week, with severe storms and flash flooding threatening parts of the Ohio Valley and Mid-Atlantic today. Scattered strong storms may bring hail, damaging winds, and isolated tornadoes, while multiple rounds of rain elevate flood risk in areas like Pittsburgh and the Central Appalachians. A deep upper low over the Great Lakes is ushering in much cooler-than-normal temperatures across the Northern Plains to the Northeast, with highs 20–35°F below average. In contrast, heat continues across the southern and western U.S., with some record-warm nights expected in Florida and southern California, and increasing heat stress forecast for south Texas. Looking ahead to the weekend, a heavy rain setup develops over the Ozarks, with flash flooding likely to expand Sunday into the Lower Mississippi Valley. As this system shifts east early next week, a wave of rain and cooler weather will spread through the South and Appalachians, while heat builds again in the Intermountain West. A late-season frost is expected to hit parts of Canada’s Maritimes and Ontario, meanwhile, Saskatchewan has some air quality issues due to wildfire smoke.
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HEADLINERS:
A multi-day heavy rain threat in the Ozarks and vicinity this weekend.
Severe Weather and flash flooding are expected over the Ohio Valley/Mid-Atlantic today.
Above-average temperatures across the southern tier states and the West; below
average temperatures from the Northern Plains to the Northeast/Mid-Atlantic.
Slight risk of high winds for parts of the California coast, Wed-Fri, May 28-30.
List via NOAA’s WPC & SPC.
ON THE RADAR:
KEEP AN EYE TO THE SKY:
IN THE GAUGES:
GRAB A RULER:
RECORDS MADE TO BE BROKEN:
ARE YOU CIRRUS?!
1896 The mercury rose to 124 degrees at Salton, CA, making it the hottest day on record for May.
1857 In Baghdad, Iraq, a dust storm lasted the entire day. Then, at about 5 pm, a darkness set in, deeper than the darkest night, and terrorized local residents.
1918 An F5 (unofficial) tornado swept foundations bare along a 37-mile path from Carroll County to Webster County, IA. Mattresses were found two miles away, and four people were killed.