Airshed
Management
System

Dispersion Discussion March 31 2026

Dan Borsum NRCC Predictive Services Meteorologist  

Smoke Dispersion Maps and charts on the NRCC Website will be updated MTWTF. 

Tuesday surface high pressure moves east across the region with over the region reaching the MT/ND border by afternoon. Cooler and stable for northern and central and southwest ID for POOR to FAIR dispersion. Breezier eastern ID for FAIR to GOOD dispersion. MT POOR to FAIR dispersion western MT and FAIR to GOOD central and eastern MT due to stronger easterly winds. 

Wednesday increasing southwest flow causes the atmosphere to become more unstable for FAIR to GOOD dispersion in most of ID and western MT. More stable in eastern MT and parts of southwest MT for POOR to FAIR dispersion. Western ID valleys more stable with POOR to FAIR dispersion. 

Thursday low pressure moves into western parts of the  region bringing chances for rain and snow. With developing low pressure expect breezy conditions for most areas FAIR to GOOD dispersion with sheltered valleys in north ID and northwest MT POOR to FAIR dispersion. More unstable in southern ID for GOOD to VERY GOOD dispersion. 

Friday system maintains winds over MT for FAIR to GOOD dispersion but ID begins to see building high pressure for POOR to FAIR dispersion.