From the National Weather Service, a Severe Thunderstorm Watch has been issued that includes much of eastern Colorado and Laramie Country in Wyoming, including the city of Cheyenne, in effect until 11:00 PM Saturday

REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes.- NWS

Graphic courtesy of National Weather Service
The NWS Storm Prediction Center has issued a

   * Severe Thunderstorm Watch for portions of 
     Eastern Colorado
     Far Southeast Wyoming

   * Effective this Saturday afternoon and evening from 230 PM until
     1100 PM MDT.

   * Primary threats include...
     Scattered damaging wind gusts to 70 mph possible
     Scattered large hail events to 1.5 inches in diameter possible

   SUMMARY...Strong-to-severe thunderstorms are expected to develop
   along the I-25/urban corridor of eastern Colorado and far southeast
   Wyoming through late afternoon. Severe hail and locally strong wind
   gusts are expected. Over time, storms/outflows should merge with
   increasing severe-wind potential late this afternoon and evening
   across the High Plains of east-central/southeast Colorado.

   The severe thunderstorm watch area is approximately along and 60
   statute miles east and west of a line from 15 miles northwest of
   Cheyenne WY to 30 miles west southwest of Springfield CO. For a
   complete depiction of the watch see the associated watch outline
   update (WOUS64 KWNS WOU3).