Airshed
Management
System

Thursday April 19 Discussion: High pressure ridging will bring limited dispersion to ID and Western MT airsheds today and tomorrow. A low pressure trough with gusty westerly winds will improve dispersion all airsheds Saturday, continuing into Sunday. Weak ridging will bring limited dispersion to portions of Central ID Monday. 

MARGINAL-GOOD dispersion Today ID and Western MT under weak ridging. Light/variable surface winds except NE-E S ID. GOOD-EXCELLENT dispersion Central/Eastern MT with E-SE surface winds. 

MARGINAL-GOOD dispersion Friday ID and Western MT under weak ridging. Light/variable surface winds except W-NW S ID and N SW MT. GOOD dispersion Central and Eastern MT with E-SE surface winds.

GOOD-EXCELLENT dispersion Saturday ID and Western MT as trough moves in. Scattered rain/snow showers. SW-W surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with strong SW-W winds Central MT and S-SW winds Eastern MT.   

GOOD dispersion Sunday ID and Western MT under westerly flow aloft. Light SW-W surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with mainly westerly surface winds.   

MARGINAL-GOOD dispersion Monday ID and Western MT under weak ridging. NE-E winds North ID and Western MT. Light/variable surface winds Central ID and SW winds S ID. GOOD-EXCELLENT dispersion Central/Eastern MT with N-NE surface winds. Rain/Snow south of the Missouri R. 

MARGINAL dispersion ID and Western MT Tuesday under high pressure ridging. Light/variable surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with S-SW  surface winds. 

GOOD dispersion Wednesday ID and Western MT under westerly flow aloft. Light westerly surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with mainly westerly surface winds.   

Friday 20 April Dispersion Forecast

MONTANA

Northwest (AS 1, 2): MARGINAL. 

West Central (AS 3A, 3B, 4, 5, 6): MARGINAL. 

Southwest (AS 7, 8A, 8B): GOOD. 

Central/Eastern (AS 9, 10): GOOD. 

IDAHO:

North (AS 11): MARGINAL. 

North Central (AS 12A, 12B, 13): MARGINAL. 

West Central (AS 14, 15, 21A): MARGINAL.

East Central (AS 16, 17): MARGINAL.

Northeast (AS 18, 19):  MARGINAL.

Southeast (AS 20): GOOD. 

Southwest (AS 21B, 22, 23, 24, 25): GOOD.

Prepared by Michael Richmond, Meteorologist NRCC

Friday April 20 Discussion: 

MARGINAL-GOOD dispersion Today ID and Western MT under weak ridging. Light/variable surface winds except W-NW S ID and N SW MT. GOOD dispersion Central and Eastern MT with E-SE surface winds.

GOOD-EXCELLENT dispersion Saturday ID and Western MT as trough moves in. Scattered rain/snow showers. SW-W surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with strong SW-W winds Central MT and S-SW winds Eastern MT.   

GOOD dispersion Sunday ID and Western MT under westerly flow aloft. Light SW-W surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with mainly westerly surface winds.   

MARGINAL-GOOD dispersion Monday ID and Western MT under weak ridging. NE-E winds North ID and Western MT. Light/variable surface winds Central ID and SW winds S ID. GOOD-EXCELLENT dispersion Central/Eastern MT with N-NE surface winds. Rain/Snow south of the Missouri R. 

MARGINAL dispersion ID and Western MT Tuesday under high pressure ridging. Light/variable surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with S-SW  surface winds. 

GOOD dispersion Wednesday ID and Western MT under westerly flow aloft. Light westerly surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with mainly westerly surface winds.   

Saturday 21 April Dispersion Forecast

MONTANA

Northwest (AS 1, 2): GOOD-EXCELLENT. 

West Central (AS 3A, 3B, 4, 5, 6):  GOOD-EXCELLENT. 

Southwest (AS 7, 8A, 8B): GOOD-EXCELLENT. 

Central/Eastern (AS 9, 10): GOOD-EXCELLENT. 

IDAHO:

North (AS 11): GOOD-EXCELLENT. 

North Central (AS 12A, 12B, 13): GOOD. 

West Central (AS 14, 15, 21A): GOOD. 

East Central (AS 16, 17): GOOD. 

Northeast (AS 18, 19): GOOD-EXCELLENT. 

Southeast (AS 20): GOOD-EXCELLENT. 

Southwest (AS 21B, 22, 23, 24, 25): GOOD-EXCELLENT. 

Prepared by Michael Richmond, Meteorologist NRCC

GOOD-EXCELLENT dispersion Saturday ID and Western MT as trough moves in. Scattered rain/snow showers. SW-W surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with strong SW-W winds Central MT and S-SW winds Eastern MT.   

GOOD dispersion Sunday ID and Western MT under westerly flow aloft. Light SW-W surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with mainly westerly surface winds.   

MARGINAL-GOOD dispersion Monday ID and Western MT under weak ridging. NE-E winds North ID and Western MT. Light/variable surface winds Central ID and SW winds S ID. GOOD-EXCELLENT dispersion Central/Eastern MT with N-NE surface winds. Rain/Snow south of the Missouri R. 

MARGINAL dispersion ID and Western MT Tuesday under high pressure ridging. Light/variable surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with S-SW  surface winds. 

GOOD dispersion Wednesday ID and Western MT under westerly flow aloft. Light westerly surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with mainly westerly surface winds.   

Sunday 22 April Dispersion Forecast

MONTANA

Northwest (AS 1, 2): GOOD.  

West Central (AS 3A, 3B, 4, 5, 6): GOOD.  

Southwest (AS 7, 8A, 8B): GOOD.  

Central/Eastern (AS 9, 10): GOOD-EXCELLENT. 

IDAHO:

North (AS 11): GOOD.  

North Central (AS 12A, 12B, 13): GOOD. 

West Central (AS 14, 15, 21A): GOOD. 

East Central (AS 16, 17): GOOD. 

Northeast (AS 18, 19): GOOD.  

Southeast (AS 20): GOOD.  

Southwest (AS 21B, 22, 23, 24, 25): GOOD.  

Prepared by Michael Richmond, Meteorologist NRCC

GOOD dispersion Sunday ID and Western MT under westerly flow aloft. Light SW-W surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with mainly westerly surface winds.   

MARGINAL-GOOD dispersion Monday ID and Western MT under weak ridging. NE-E winds North ID and Western MT. Light/variable surface winds Central ID and SW winds S ID. GOOD-EXCELLENT dispersion Central/Eastern MT with N-NE surface winds. Rain/Snow south of the Missouri R. 

MARGINAL dispersion ID and Western MT Tuesday under high pressure ridging. Light/variable surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with S-SW  surface winds. 

GOOD dispersion Wednesday ID and Western MT under westerly flow aloft. Light westerly surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with mainly westerly surface winds.   

Monday 23 April Dispersion Forecast

MONTANA

Northwest (AS 1, 2): GOOD.  

West Central (AS 3A, 3B, 4, 5, 6): GOOD.  

Southwest (AS 7, 8A, 8B): GOOD.  

Central/Eastern (AS 9, 10): GOOD-EXCELLENT. 

IDAHO:

North (AS 11): GOOD.  

North Central (AS 12A, 12B, 13): MARGINAL. 

West Central (AS 14, 15, 21A): MARGINAL. 

East Central (AS 16, 17): MARGINAL. 

Northeast (AS 18, 19): GOOD.  

Southeast (AS 20): GOOD.  

Southwest (AS 21B, 22, 23, 24, 25): GOOD.  

Prepared by Michael Richmond, Meteorologist NRCC

MARGINAL-GOOD dispersion Monday ID and Western MT under weak ridging. NE-E winds North ID and Western MT. Light/variable surface winds Central ID and SW winds S ID. GOOD-EXCELLENT dispersion Central/Eastern MT with N-NE surface winds. Rain/Snow south of the Missouri R. 

MARGINAL dispersion ID and Western MT Tuesday under high pressure ridging. Light/variable surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with S-SW  surface winds. 

GOOD dispersion Wednesday ID and Western MT under westerly flow aloft. Light westerly surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with mainly westerly surface winds.   

Tuesday 24 April Dispersion Forecast

MONTANA

Northwest (AS 1, 2): MARGINAL. 

West Central (AS 3A, 3B, 4, 5, 6): MARGINAL. 

Southwest (AS 7, 8A, 8B): MARGINAL. 

Central/Eastern (AS 9, 10): GOOD-EXCELLENT. 

IDAHO:

North (AS 11): MARGINAL. 

North Central (AS 12A, 12B, 13): MARGINAL. 

West Central (AS 14, 15, 21A): MARGINAL. 

East Central (AS 16, 17): MARGINAL. 

Northeast (AS 18, 19): MARGINAL. 

Southeast (AS 20): MARGINAL.  

Southwest (AS 21B, 22, 23, 24, 25): MARGINAL. 

Prepared by Michael Richmond, Meteorologist NRCC

MARGINAL dispersion ID and Western MT Tuesday under high pressure ridging. Light/variable surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with S-SW  surface winds. 

GOOD dispersion Wednesday ID and Western MT under westerly flow aloft. Light westerly surface winds. GOOD-EXCELLENT dispersion Central/Eastern MT with mainly westerly surface winds.   

Wednesday 25 April Dispersion Forecast

MONTANA

Northwest (AS 1, 2): GOOD. 

West Central (AS 3A, 3B, 4, 5, 6):  GOOD.

Southwest (AS 7, 8A, 8B): GOOD.

Central/Eastern (AS 9, 10): GOOD-EXCELLENT. 

IDAHO:

North (AS 11): GOOD.

North Central (AS 12A, 12B, 13): GOOD.

West Central (AS 14, 15, 21A): GOOD.

East Central (AS 16, 17): GOOD.

Northeast (AS 18, 19): GOOD.

Southeast (AS 20): GOOD.

Southwest (AS 21B, 22, 23, 24, 25): GOOD.

Prepared by Michael Richmond, Meteorologist NRCC