Isolated thunderstorms are possible this afternoon and evening over the mountains, mainly north of Cottonwood Pass. 

Near critical fire weather conditions are expected across the San Luis Valley.  

Salida and Buena Vista can expect a high of 75. Look for an overnight low of 47.    
The San Luis Valley will see a high of 73, a low of 45.  
Leadville and Fairplay will warm up to 61 with a low of 37.