AUUS46 KPDT 111225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT SAT APR 11 2026

*** AIR DISPERSION CATEGORIES:   GOOD, FAIR, POOR ***

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 5-10 MPH.         SW 13-19 MPH.
TRANSPORT WINDS               SW 7-12 MPH.        W 15-20 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SUN APR 12        POOR.               
OUTLOOK FOR MON APR 13        GOOD.               

VENTILATION INDEX (CATEGORY)  114 (POOR).         748 (GOOD).
OUTLOOK FOR SUN APR 12        131 (POOR).         
OUTLOOK FOR MON APR 13        970 (GOOD).         

FOR THE UPPER YAKIMA VALLEY INCLUDING YAKIMA...UNION GAP...
SELAH...AND NACHES AREA

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SW 2-5 MPH.         W 8-11 MPH.
TRANSPORT WINDS               W 3-7 MPH.          W 11-15 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR SUN APR 12        POOR.               
OUTLOOK FOR MON APR 13        GOOD.               

VENTILATION INDEX (CATEGORY)  61 (POOR).          570 (FAIR).
OUTLOOK FOR SUN APR 12        158 (POOR).         
OUTLOOK FOR MON APR 13        748 (GOOD).         

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 4-8 MPH.          SW 6-10 MPH.
TRANSPORT WINDS               S 10-13 MPH.        W 9-11 MPH.
MIXING HEIGHT                 4000 FT MSL.        6500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SUN APR 12        FAIR.               
OUTLOOK FOR MON APR 13        GOOD.               

VENTILATION INDEX (CATEGORY)  199 (POOR).         440 (FAIR).
OUTLOOK FOR SUN APR 12        166 (POOR).         
OUTLOOK FOR MON APR 13        566 (FAIR).         

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 4-8 MPH.          W 9-17 MPH.
TRANSPORT WINDS               SW 7-13 MPH.        W 10-22 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SUN APR 12        POOR.               
OUTLOOK FOR MON APR 13        GOOD.               

VENTILATION INDEX (CATEGORY)  124 (POOR).         531 (FAIR).
OUTLOOK FOR SUN APR 12        114 (POOR).         
OUTLOOK FOR MON APR 13        850 (GOOD).         

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      477 (FAIR)
ELLENSBURG    470 (FAIR)
GOLDENDALE    672 (GOOD)
TRI-CITIES    858 (GOOD)
WALLA WALLA   593 (FAIR)
YAKIMA        370 (FAIR)
BEND          625 (GOOD)
PRINEVILLE    439 (FAIR)
ENTERPRISE    756 (GOOD)
HERMISTON     779 (GOOD)
JOHN DAY      856 (GOOD)
LA GRANDE     452 (FAIR)
MADRAS        262 (POOR)
MEACHAM       297 (POOR)
PENDLETON     556 (FAIR)
REDMOND       439 (FAIR)
SENECA       1000 (GOOD)
THE DALLES    532 (FAIR)

METEOROLOGICAL INFORMATION PROVIDED IN THIS PRODUCT REPRESENTS ONLY
SOME OF THE FACTORS USED IN BURN DECISIONS.  BURN DECISIONS ARE
OUTSIDE THE PURVIEW OF THE NATIONAL WEATHER SERVICE.

THE VENTILATION INDEX IS A TOOL TO ASSIST SMOKE MANAGEMENT
AGENCIES IN DETERMINING BURN OR NO BURN DECISIONS.  A VENTILATION
INDEX GRAPHIC IS ON THE PENDLETON WEBSITE AT THE FOLLOWING ADDRESS:
HTTPS://WWW.WEATHER.GOV/PDT/DSSBRIEFING

IF YOU WOULD LIKE TO KNOW MORE ABOUT THIS PRODUCT...CONTACT THE
NATIONAL WEATHER SERVICE IN PENDLETON.
$$