Airshed
Management
System

Wednesday 14 April Discussion:  Northeasterly flow aloft and at the surface will continue today with a broad trough of low pressure over the Northern Rockies and Plains and another low pressure center developing in the Great Basin. Precipitation potential will be focused in southern Idaho and central/eastern Montana leaving many of the western airsheds dry. On Friday and Saturday a ridge of high pressure will overspread the Pacific Northwest including northern Idaho and western Montana with a more stable pattern bringing limited smoke dispersion in the western airsheds. This will be interrupted on Sunday with a fast-moving trough of low pressure that will move through the Northern Rockies from north to south with only slightly better smoke dispersion but also a quick shot of moisture. Thereafter, the first half of next week offers relatively drier northwest flow aloft under broad high pressure ridging with limited smoke dispersion.

GOOD smoke dispersion in Idaho and western Montana Today with northeast flow aloft and at the surface. Isolated showers. GOOD smoke dispersion in central/eastern Montana with northeast flow aloft and at the surface.

MARGINAL-GOOD smoke dispersion in Idaho and western Montana Thursday with north-northeast flow aloft and at the surface. MARGINAL-GOOD smoke dispersion in central/eastern Montana with weak northeast flow aloft. Light east-northeast surface winds. Isolated showers along the Continental Divide and in the mountains of southern Montana. 

MARGINAL smoke dispersion in Idaho and western Montana Friday with northeast flow aloft and at the surface. MARGINAL smoke dispersion in central/eastern Montana with northeast flow aloft. Light north-northeast surface winds. Isolated showers in the mountains of southern Montana. 

POOR-MARGINAL smoke dispersion in Idaho and western Montana Saturday with northeast flow aloft/high pressure ridging. MARGINAL-GOOD smoke dispersion in central/eastern Montana with northerly flow aloft. Light surface winds in central Montana but moderate northeast surface winds in eastern Montana.

MARGINAL smoke dispersion in Idaho and western Montana Sunday with  MARGINAL-GOOD smoke dispersion in central/eastern Montana with northwest flow aloft/fast moving trough of low pressure. Light northeast surface winds.  Widespread showers in western Montana. GOOD-EXCELLENT smoke dispersion in central/eastern Montana with northwest flow aloft/fast moving upper level trough. Light to moderate northerly surface winds. Scattered showers.

POOR-MARGINAL smoke dispersion in Idaho and western Montana Monday with northwest flow aloft/weak trough of low pressure. Isolated rain showers. GOOD smoke dispersion in central/eastern Montana with northwest flow aloft. Light northeast surface winds. Scattered showers.

Thursday 15 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.

IDAHO:

North (AS 11): MARGINAL.

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

West Central (AS 14, 15): MARGINAL.

East Central (AS 16, 17):  MARGINAL.

Southeast (AS 18, 19, 20): MARGINAL.

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

Prepared by Coleen Haskell, NRCC Meteorologist

Thursday 15 April Discussion:  Smoke dispersion will be favorable overall with the exception of Saturday and Sunday when it will be more limited in the western airsheds due to the influence of a high pressure ridge.

Northeasterly flow aloft and at the surface will continue today and Friday while the Northern Rockies is positioned between a ridge of high pressure in the Pacific Northwest and a trough of low pressure in the Central Rockies.  While surface winds will remain from the northeast today and tomorrow, the impacts of the high pressure will increase on Friday and Saturday with a more stable pattern bringing limited smoke dispersion in the western airsheds for Saturday and Sunday. After that, beginning Sunday night better mixing will result as a trough of low pressure in northwest flow will bring periods of showers but also better dispersion. This pattern may persist into next week with unsettled conditions in northwest flow, while the high pressure remains to our west.

MARGINAL-GOOD smoke dispersion in Idaho and western Montana Today with northeast flow aloft and at the surface. Scattered showers in southern Idaho. MARGINAL-GOOD smoke dispersion in central/eastern Montana with weak northeast flow aloft and at the surface. Isolated showers along the Continental Divide and in the mountains of southern Montana. 

MARGINAL smoke dispersion in Idaho and western Montana Friday with northeast flow aloft and at the surface/ridge of high pressure building in from the west. MARGINAL smoke dispersion in central/eastern Montana with northeast flow aloft. North-northeast surface winds. Isolated showers in the mountains of southern Montana. 

POOR-MARGINAL smoke dispersion in Idaho and western Montana Saturday with northerly flow aloft/high pressure ridging. MARGINAL-GOOD smoke dispersion in central/eastern Montana with northerly flow aloft/high pressure ridging. Light northwest surface winds.

MARGINAL smoke dispersion in Idaho and western Montana Sunday with northwest flow aloft. GOOD-EXCELLENT smoke dispersion in central/eastern Montana with northwest flow aloft/upper level trough. Light to moderate northerly surface winds. Scattered showers in northcentral Montana.

GOOD smoke dispersion in Idaho and western Montana Monday with northwest flow aloft/trough of low pressure. Scattered rain and mountain snow showers in western Montana. GOOD smoke dispersion in central/eastern Montana with northwest flow aloft/trough of low pressure. Light north-northeast surface winds. Widespread showers.

GOOD smoke dispersion in Idaho and western Montana Tuesday with northwest flow aloft/trough of low pressure. Scattered rain and mountain snow showers, more widespread in central Idaho. GOOD smoke dispersion in central/eastern Montana with northwest flow aloft/trough of low pressure. Light north-northwest surface winds. Widely scattered showers.

MARGINAL smoke dispersion in Idaho and western Montana Wednesday with weak northerly flow aloft. Isolated showers in central/southern Idaho. MARGINAL-GOOD smoke dispersion in central/eastern Montana with weak northwest flow aloft. Light southwest-west surface winds. 

Friday 16 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): MARGINAL.

IDAHO:

North (AS 11): MARGINAL.

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

West Central (AS 14, 15): MARGINAL.

East Central (AS 16, 17):  GOOD.

Southeast (AS 18, 19, 20):GOOD.

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

Prepared by Coleen Haskell, NRCC Meteorologist

MARGINAL smoke dispersion in Idaho and western Montana Today with northeast flow aloft and at the surface/ridge of high pressure building in from the west. MARGINAL smoke dispersion in central/eastern Montana with northeast flow aloft. North-northeast surface winds. Isolated showers in the mountains of southern Montana. 

POOR-MARGINAL smoke dispersion in Idaho and western Montana Saturday with northerly flow aloft/high pressure ridging. MARGINAL-GOOD smoke dispersion in central/eastern Montana with northerly flow aloft/high pressure ridging. Light northwest surface winds.

MARGINAL smoke dispersion in Idaho and western Montana Sunday with northwest flow aloft. GOOD-EXCELLENT smoke dispersion in central/eastern Montana with northwest flow aloft/upper level trough. Light to moderate northerly surface winds. Scattered showers in northcentral Montana.

GOOD smoke dispersion in Idaho and western Montana Monday with northwest flow aloft/trough of low pressure. Scattered rain and mountain snow showers in western Montana. GOOD smoke dispersion in central/eastern Montana with northwest flow aloft/trough of low pressure. Light north-northeast surface winds. Widespread showers.

GOOD smoke dispersion in Idaho and western Montana Tuesday with northwest flow aloft/trough of low pressure. Scattered rain and mountain snow showers, more widespread in central Idaho. GOOD smoke dispersion in central/eastern Montana with northwest flow aloft/trough of low pressure. Light north-northwest surface winds. Widely scattered showers.

MARGINAL smoke dispersion in Idaho and western Montana Wednesday with weak northerly flow aloft. Isolated showers in central/southern Idaho. MARGINAL-GOOD smoke dispersion in central/eastern Montana with weak northwest flow aloft. Light southwest-west surface winds. 

Saturday 17 April Dispersion Forecast

MONTANA:

Northwest (AS 1, 2): POOR.

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

Southwest (AS 7, 8A, 8B):  POOR.

Central/Eastern (AS 9, 10): MARGINAL western half, GOOD eastern half.

IDAHO:

North (AS 11): MARGINAL.

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

West Central (AS 14, 15): MARGINAL.

East Central (AS 16, 17):  POOR.

Southeast (AS 18, 19, 20): MARGINAL.

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

Prepared by Coleen Haskell, NRCC Meteorologist

POOR-MARGINAL smoke dispersion in Idaho and western Montana Today with northerly flow aloft/high pressure ridging. MARGINAL-GOOD smoke dispersion in central/eastern Montana with northerly flow aloft/high pressure ridging. Light northwest surface winds.

MARGINAL smoke dispersion in Idaho and western Montana Sunday with northwest flow aloft. GOOD-EXCELLENT smoke dispersion in central/eastern Montana with northwest flow aloft/upper level trough. Light to moderate northerly surface winds. Scattered showers in northcentral Montana.

GOOD smoke dispersion in Idaho and western Montana Monday with northwest flow aloft/trough of low pressure. Scattered rain and mountain snow showers in western Montana. GOOD smoke dispersion in central/eastern Montana with northwest flow aloft/trough of low pressure. Light north-northeast surface winds. Widespread showers.

GOOD smoke dispersion in Idaho and western Montana Tuesday with northwest flow aloft/trough of low pressure. Scattered rain and mountain snow showers, more widespread in central Idaho. GOOD smoke dispersion in central/eastern Montana with northwest flow aloft/trough of low pressure. Light north-northwest surface winds. Widely scattered showers.

MARGINAL smoke dispersion in Idaho and western Montana Wednesday with weak northerly flow aloft. Isolated showers in central/southern Idaho. MARGINAL-GOOD smoke dispersion in central/eastern Montana with weak northwest flow aloft. Light southwest-west surface winds. 

Sunday 18 April Dispersion Forecast

MONTANA:

Northwest (AS 1, 2): MARGINAL in AS 01. GOOD in AS 02.

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

Southwest (AS 7, 8A, 8B):  MARGINAL.

Central/Eastern (AS 9, 10): GOOD in AS 10.  EXCELLENT in AS 09.

IDAHO:

North (AS 11): MARGINAL.

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

West Central (AS 14, 15): MARGINAL.

East Central (AS 16, 17):  MARGINAL.

Southeast (AS 18, 19, 20): MARGINAL.

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

Prepared by Coleen Haskell, NRCC Meteorologist

MARGINAL smoke dispersion in Idaho and western Montana Today with northwest flow aloft. GOOD-EXCELLENT smoke dispersion in central/eastern Montana with northwest flow aloft/upper level trough. Light to moderate northerly surface winds. Scattered showers in northcentral Montana.

GOOD smoke dispersion in Idaho and western Montana Monday with northwest flow aloft/trough of low pressure. Scattered rain and mountain snow showers in western Montana. GOOD smoke dispersion in central/eastern Montana with northwest flow aloft/trough of low pressure. Light north-northeast surface winds. Widespread showers.

GOOD smoke dispersion in Idaho and western Montana Tuesday with northwest flow aloft/trough of low pressure. Scattered rain and mountain snow showers, more widespread in central Idaho. GOOD smoke dispersion in central/eastern Montana with northwest flow aloft/trough of low pressure. Light north-northwest surface winds. Widely scattered showers.

MARGINAL smoke dispersion in Idaho and western Montana Wednesday with weak northerly flow aloft. Isolated showers in central/southern Idaho. MARGINAL-GOOD smoke dispersion in central/eastern Montana with weak northwest flow aloft. Light southwest-west surface winds. 

Monday 19 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.

IDAHO:

North (AS 11): GOOD.

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

West Central (AS 14, 15): GOOD.

East Central (AS 16, 17):  GOOD.

Southeast (AS 18, 19, 20): EXCELLENT.

Prepared by Coleen Haskell, NRCC Meteorologist

GOOD smoke dispersion in Idaho and western Montana Today with northwest flow aloft/trough of low pressure. Scattered rain and mountain snow showers in western Montana. GOOD smoke dispersion in central/eastern Montana with northwest flow aloft/trough of low pressure. Light north-northeast surface winds. Widespread showers.

GOOD smoke dispersion in Idaho and western Montana Tuesday with northwest flow aloft/trough of low pressure. Scattered rain and mountain snow showers, more widespread in central Idaho. GOOD smoke dispersion in central/eastern Montana with northwest flow aloft/trough of low pressure. Light north-northwest surface winds. Widely scattered showers.

MARGINAL smoke dispersion in Idaho and western Montana Wednesday with weak northerly flow aloft. Isolated showers in central/southern Idaho. MARGINAL-GOOD smoke dispersion in central/eastern Montana with weak northwest flow aloft. Light southwest-west surface winds. 

Tuesday 20 April Dispersion Forecast

MONTANA:

Northwest (AS 1, 2): GOOD.

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

Southwest (AS 7, 8A, 8B):  EXCELLENT.

Central/Eastern (AS 9, 10): GOOD in western half.  Excellent in eastern half.

IDAHO:

North (AS 11): GOOD.

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

West Central (AS 14, 15): MARGINAL.

East Central (AS 16, 17):  GOOD.

Southeast (AS 18, 19, 20): GOOD.

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

Prepared by Coleen Haskell, NRCC Meteorologist