T-storms and rain on the way
Strong wind gusts possible
May 20, 2008
The National Weather Service says a change in the weather is approaching. Scattered to numerous showers and isolated thunderstorms will affect western and southern Wyoming Tuesday night. Some of this activity Tuesday evening, even the showers, could produce wind gusts to near 55 mph.
A strong cold front will move across the state Wednesday bringing much cooler temperatures as well as significant widespread precipitation. A few thunderstorms are also expected. The cold front will be through much of western and central Wyoming by noon on Wednesday. This will limit the strong thunderstorm threat to southeast Fremont and Natrona counties where heavy rain, small hail and gusty winds are possible.
Rain is expected to develop over the north and west Wednesday, becoming widespread throughout the afternoon. Southeast upslope flow will bring significant rainfall to Johnson and Natrona counties Wednesday night into Thursday. Rainfall amounts of 1 to 2 inches are likely. This rainfall on deep snowpack in the mountains will increase the flooding threat from excessive runoff in the Bighorn Mountains and Casper mountain. The rain will begin to diminish mid-day Thursday.
The atmosphere will be colder over the western portion of the area. Easterly upslope flow is expected over the Wind River Mountains and basin. This will bring the potential for significant rainfall in lower elevations, with snow in the mountains. Twelve to fifteen inches of snowfall is possible in the east slope of the Wind River Mountains Wednesday night into Thursday. South Pass and Togwotee Pass could become snowpacked and treacherous. The precipitation is expected to diminish Thursday afternoon and evening.