The Riverton office of the National Weather Service is warning of flash flooding in south Casper to at least 9:30 p.m.

A wide swath of three-quarters of an inch up to one inch of rain has fallen on Casper Mountain, with some of the heavier rain since 7:35 p.m. falling on the north face of the mountain.

The heavy rain may cause flooding in the Garden Creek drainage. This drainage flows north toward Wyoming Boulevard and the south side of Casper. Additional rainfall amounts of up to 1 inch are possible in the warned area through 9 p.m.

Flood waters are likely to move down drainages on the north face of Casper Mountain. This includes Garden Creek, Wolf Creek, and Little Red Creek drainages.

The flood waters also are expected to affect Big Red and Little Red creeks on the south side of the mountain.

The National Weather Service warns water crossings in hilly terrain are potentially dangerous in heavy rain.

Do not attempt to cross flooded roads, and find alternate routes.

Report flooding to your local law enforcement agency when you
can do so safely.


The National Weather Service has issued a significant thunderstorm and flash flood warnings for southeastern Natrona County until 9:30 p.m., and a significant weather advisory will continue after that.
At 7:15 p.m., a severe thunderstorm was located near Beartrap Meadows County Park, which is on Casper Mountain 10 miles south of Casper.

The thunderstorm was moving east at 15 mph. Another storm has occurred just east of Evansville.

The Riverton office of the NWS said Casper Mountain and Outer Drive are subject to torrential rains and flash floods.

At 7:45 p.m., a severe thunderstorm was located eight miles northeast of Independence Rock, which is 10 miles west of Alcova, moving east at 15 mph. The thunderstorm will be near Alcova about 8:30 p.m.

The NWS also is warning of 60 mph wind gusts and quarter size hail.

Hail damage to vehicles is expected. Expect wind damage to roofs, siding, and trees.

This includes Interstate 25 between mile markers 176 and 190.

These showers and thunderstorms were moving very slowly, and have the potential to produce torrential rainfall in a short amount of time. This could cause sharp rises on small creeks and in urban areas depending how long the rain lasts.

Local flooding is possible.

The NWS cautions motorists to not drive vehicles through flooded roadways.