Airshed
Management
System

March 20 Discussion

Maps of the airshed ratings available here: 

Charts for the individual airsheds here: This includes the airshed table. 

Pretty simple forecast.

 Multiple weather systems passing over ID and MT Thursday, Friday and Saturday will bring a fair amount of wind and unsettled conditions for GOOD to VERY GOOD dispersion. There will be rain and snow shower activity mainly along and west of the Continental Divide. ID will see a few areas of POOR to FAIR dispersion as the valleys struggle to warm up on Friday. 

Next week stability trends to POOR for many airsheds as upper level high pressure becomes dominant over the region. Valleys still with snow cover will have the toughest time breaking inversion, but smoke lift will be limited with caps in place at the surround ridgetops. Parts of central and eastern MT will still have GOOD dispersion due to mix down winds in the afternoon hours.