A cold front extended from the central Plains to the Mid-Atlantic on Friday. As warm, humid air interacted with this frontal boundary, strong thunderstorms developed across the Deep South and the southern Mid-Atlantic.
Flash flood warnings were issued in eastern Arkansas and northern Louisiana due to heavy rain across the region. Sea breeze induced thunderstorms also popped up across Florida. Miami, Fla., reported a midday total of 0.92 inches of rain.
Meanwhile, a cold front extended across the upper Intermountain West, the northern Plains and the upper Mississippi Valley. Showers and thunderstorms developed ahead of this front over several states, as Denison, Iowa, reported a midday total of 0.98 inches of rain.
Just to the east, high pressure kept conditions clear across the Ohio Valley, the eastern Great Lakes and the Northeast. Cooler than normal temperatures accompanied this high pressure, as Saranac Lake, N.Y., recorded a morning low of 39 degrees.
Monsoonal moisture initiated widespread rain and thunderstorms over the Intermountain West, the Great Basin and parts of the West Coast on Friday. The heaviest rain focused over parts of Wyoming and southwest Oregon. The Southwest stayed mostly clear of precipitation due to a ridge of high pressure over the eastern Pacific.
FRIDAY'S WEATHER EXTREMES:
HIGHEST TEMPERATURE (DEGREES F).........................102 Blythe, Calif.
HIGHEST HEAT INDEX (DEGREES F)..........................108 Ellington Field, Texas
LOWEST TEMPERATURE (DEGREES F)..........................39 Stanley, Idaho
LOWEST WIND CHILL (DEGREES F)...........................26 Wainwright, Alaska
HIGHEST WIND GUST (MPH).................................59 Portage Glacier, Alaska
HIGHEST PRECIPITATION (INCHES)..........................2.07 Little Falls, Minn.
ON THIS DATE....... How much damage did the costliest hailstorm in U.S. history cause? Well, on this date in 1990, a hailstorm along the Front Range in the Rockies produced baseball-sized hail that stripped trees, damaged cars and knocked out power to thousands. The final damage tally was at $625 million.