The National Weather Service is tracking a strong thunderstorm five miles southwest of Interstate-25 about 26 miles north of Casper.
The weather service also has updated its winter weather predictions from Tuesday.
The thunderstorm is moving east at 35 mph, according to a special weather statement from the NWS.
Hail up to one-half-inch in diameter and wind gusts up to 40 mph are expected with this storm along with heavy rain and frequent and dangerous lightning.
This storm will be in the area of I-25 between mile markers 202 and 224 until about 2:55 p.m.
The National Weather Service cautions people to take shelter in a sturdy building if a thunderstorm approaches.
Brief heavy rain, which may flood low-lying areas, is also likely. Do not drive your vehicle on a flooded roadway.
Later Wednesday, the National Weather Service is predicting scattered rain showers before 5 p.m., then rain and snow showers likely. Some thunder is also possible.
Skies will be mostly cloudy, with a high near 47. Winds will be west-southwest about 16 mph, with gusts as high as 23 mph.
Chance of precipitation is 60 percent. Little or no snow accumulation expected until about 8 p.m. Some thunder is also possible.
Wednesday night, skies will be cloudy, with low temperatures around 26.
Expect blustery winds, with a west-northwest wind 14 to 21 mph becoming north in the evening.
Winds could gust as high as 29 mph. Chance of precipitation is 70 percent.
New snow accumulation of 3 to 7 inches is possible.
On Thursday, scattered snow showers will continue until noon.
Skies will be mostly sunny with a high near 40.
Winds will be from 8 to 13 mph becoming light west-northwest in the afternoon.
Chance of precipitation is 40%. New snow accumulation will amount to less than a half inch.