Airshed
Management
System

Thursday May 23 Discussion: The basic pattern of upper troughs sliding south to the west of ID and MT, moving east into the Great Basin, then north over the plains will continue into early next week. This is a favorable dispersion pattern generally for all the airsheds. NE-E low level flow will persist today but will switch back to westerly tomorrow for all but airshed 9 as a low center moves into North Dakota. Low level flow will shift back to NE-E Sun/Mon next week most airsheds as another trough undercuts to our south. 

GOOD-EXCELLENT dispersion Today in ID and Western MT under broad trough of low pressure. NE-E surface winds. Scattered showers Southern ID. GOOD-EXCELLENT dispersion in Central and Eastern MT with SE-E surface winds. Scattered showers in Southern MT. 

GOOD-EXCELLENT dispersion Friday in ID and Western MT in between weather systems. SW-W surface winds. Scattered showers/wet storms. GOOD-EXCELLENT dispersion in Central and Eastern MT with NE-E surface winds north of the Missouri R. NW-W to the south. Scattered showers/wet storms.  

GOOD-EXCELLENT dispersion Saturday in ID and Western MT with SW flow aloft. S-W surface winds except NE-E near Continental Divide in Western MT. Scattered showers/ wet storms. GOOD dispersion in Central and Eastern MT with SE-E surface winds. Scattered showers/wet storms Central MT. 

GOOD-EXCELLENT dispersion Sunday in ID and Western MT with Southerly flow aloft. N-E surface winds North and Central ID and NW MT. S-SE winds South ID and SW MT. Scattered showers/wet storms. EXCELLENT dispersion in Central and Eastern MT with E-NE surface winds As 9 and NW-W in As 10. Scattered showers/wet storms.

GOOD dispersion Monday in ID and Western MT with weak NW flow aloft. W-NW surface winds except NE-E along Continental Divide and SW MT. GOOD dispersion in Central and Eastern MT with weak E flow aloft and NE-E surface winds. 

GOOD-EXCELLENT dispersion Tuesday for Idaho and Western MT under weak NW flow aloft. W-NW surface winds. Isolated showers. EXCELLENT dispersion Central/Eastern MT with W-NW surface winds. 

GOOD-EXCELLENT dispersion Wednesday for Idaho and Western MT as upper trough moves through North ID. SW-W surface winds. Scattered showers. GOOD dispersion Central/Eastern MT with SW-W surface winds. 

Friday May 24 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 As 9. EXCELLENT As 10. 

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): EXCELLENT. 

Southeast (AS 20):  EXCELLENT.

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

Prepared by Michael Richmond and Coleen Haskell Meteorologists, NRCC

Friday May 24 Discussion: 

GOOD-EXCELLENT dispersion Today in ID and Western MT in between weather systems. SW-W surface winds. Scattered showers/wet storms. GOOD-EXCELLENT dispersion in Central and Eastern MT with NE-E surface winds north of the Missouri R. NW-W to the south. Scattered showers/wet storms.  

GOOD-EXCELLENT dispersion Saturday in ID and Western MT with SW flow aloft. S-W surface winds except NE-E near Continental Divide in Western MT. Scattered showers/ wet storms. GOOD dispersion in Central and Eastern MT with SE-E surface winds. Scattered showers/wet storms Central MT. 

GOOD-EXCELLENT dispersion Sunday in ID and Western MT with Southerly flow aloft. N-E surface winds North and Central ID and NW MT. S-SE winds South ID and SW MT. Scattered showers/wet storms. EXCELLENT dispersion in Central and Eastern MT with E-NE surface winds As 9 and NW-W in As 10. Scattered showers/wet storms.

GOOD dispersion Monday in ID and Western MT with weak NW flow aloft. W-NW surface winds except NE-E along Continental Divide and SW MT. GOOD dispersion in Central and Eastern MT with weak E flow aloft and NE-E surface winds. 

GOOD-EXCELLENT dispersion Tuesday for Idaho and Western MT under weak NW flow aloft. W-NW surface winds. Isolated showers. EXCELLENT dispersion Central/Eastern MT with W-NW surface winds. 

GOOD-EXCELLENT dispersion Wednesday for Idaho and Western MT as upper trough moves through North ID. SW-W surface winds. Scattered showers. GOOD dispersion Central/Eastern MT with SW-W surface winds. 

Saturday May 25 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.

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): EXCELLENT. 

Southeast (AS 20):  EXCELLENT.

Southwest (AS 21B, 22, 23, 24, 25):  EXCELLENT except GOOD As 21B/22.

Prepared by Michael Richmond and Coleen Haskell Meteorologists, NRCC

GOOD-EXCELLENT dispersion Saturday in ID and Western MT with SW flow aloft. S-W surface winds except NE-E near Continental Divide in Western MT. Scattered showers/ wet storms. GOOD dispersion in Central and Eastern MT with SE-E surface winds. Scattered showers/wet storms Central MT. 

GOOD-EXCELLENT dispersion Sunday in ID and Western MT with Southerly flow aloft. N-E surface winds North and Central ID and NW MT. S-SE winds South ID and SW MT. Scattered showers/wet storms. EXCELLENT dispersion in Central and Eastern MT with E-NE surface winds As 9 and NW-W in As 10. Scattered showers/wet storms.

GOOD dispersion Monday in ID and Western MT with weak NW flow aloft. W-NW surface winds except NE-E along Continental Divide and SW MT. GOOD dispersion in Central and Eastern MT with weak E flow aloft and NE-E surface winds. 

GOOD-EXCELLENT dispersion Tuesday for Idaho and Western MT under weak NW flow aloft. W-NW surface winds. Isolated showers. EXCELLENT dispersion Central/Eastern MT with W-NW surface winds. 

GOOD-EXCELLENT dispersion Wednesday for Idaho and Western MT as upper trough moves through North ID. SW-W surface winds. Scattered showers. GOOD dispersion Central/Eastern MT with SW-W surface winds. 

Sunday May 26 Dispersion Forecast

MONTANA:
Northwest (AS 1, 2):  GOOD As 1, EXCELLENT As 2.
West Central (AS 3A, 3B, 4, 5, 6):  EXCELLENT except GOOD As 4. 

Southwest (AS 7, 8A, 8B): EXCELLENT. 

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

IDAHO:

North (AS 11): 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): EXCELLENT. 

Southeast (AS 20):  EXCELLENT.

Southwest (AS 21B, 22, 23, 24, 25):  EXCELLENT except GOOD As 21B/22.

Prepared by Michael Richmond and Coleen Haskell Meteorologists, NRCC

GOOD-EXCELLENT dispersion Sunday in ID and Western MT with Southerly flow aloft. N-E surface winds North and Central ID and NW MT. S-SE winds South ID and SW MT. Scattered showers/wet storms. EXCELLENT dispersion in Central and Eastern MT with E-NE surface winds As 9 and NW-W in As 10. Scattered showers/wet storms.

GOOD dispersion Monday in ID and Western MT with weak NW flow aloft. W-NW surface winds except NE-E along Continental Divide and SW MT. GOOD dispersion in Central and Eastern MT with weak E flow aloft and NE-E surface winds. 

GOOD-EXCELLENT dispersion Tuesday for Idaho and Western MT under weak NW flow aloft. W-NW surface winds. Isolated showers. EXCELLENT dispersion Central/Eastern MT with W-NW surface winds. 

GOOD-EXCELLENT dispersion Wednesday for Idaho and Western MT as upper trough moves through North ID. SW-W surface winds. Scattered showers. GOOD dispersion Central/Eastern MT with SW-W surface winds. 

Monday May 27 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.

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 and Coleen Haskell Meteorologists, NRCC

GOOD dispersion Monday in ID and Western MT with weak NW flow aloft. W-NW surface winds except NE-E along Continental Divide and SW MT. GOOD dispersion in Central and Eastern MT with weak E flow aloft and NE-E surface winds. 

GOOD-EXCELLENT dispersion Tuesday for Idaho and Western MT under weak NW flow aloft. W-NW surface winds. Isolated showers. EXCELLENT dispersion Central/Eastern MT with W-NW surface winds. 

GOOD-EXCELLENT dispersion Wednesday for Idaho and Western MT as upper trough moves through North ID. SW-W surface winds. Scattered showers. GOOD dispersion Central/Eastern MT with SW-W surface winds. 

Tuesday May 28 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.

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): EXCELLENT. 

Southeast (AS 20):  EXCELLENT. 

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

Prepared by Michael Richmond and Coleen Haskell Meteorologists, NRCC

GOOD-EXCELLENT dispersion Tuesday for Idaho and Western MT under weak NW flow aloft. W-NW surface winds. Isolated showers. EXCELLENT dispersion Central/Eastern MT with W-NW surface winds. 

GOOD-EXCELLENT dispersion Wednesday for Idaho and Western MT as upper trough moves through North ID. SW-W surface winds. Scattered showers. GOOD dispersion Central/Eastern MT with SW-W surface winds. 

Wednesday May 30 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.

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): EXCELLENT. 

Southeast (AS 20):  EXCELLENT. 

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

Prepared by Michael Richmond and Coleen Haskell Meteorologists, NRCC