11.   Spotty thunderstorms will erupt Sunday afternoon and evening as the uneven heating of mountains and valleys incites rising currents of moist air.

12.   Thunder will develop over the Rockies Friday afternoon, as the mountain peaks provide an elevated source of heat for rising air currents.

13.   Widely separated storms will also flare from the Sierra Nevada of California to the southern Rockies as the uneven heating of mountains and valleys promotes rising currents of air.