810
AUUS46 KPDT 071225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT THU MAY  7 2026

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SW 8-18 MPH.        SW 8-14 MPH.
TRANSPORT WINDS               SW 10-19 MPH.       SW 8-14 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6000 FT MSL.
DISPERSION CATEGORY           FAIR.               FAIR.
OUTLOOK FOR FRI MAY 8         GOOD.
OUTLOOK FOR SAT MAY 9         POOR.

VENTILATION INDEX (CATEGORY)  159 (POOR).         444 (FAIR).
OUTLOOK FOR FRI MAY 8         979 (GOOD).
OUTLOOK FOR SAT MAY 9         248 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 4-8 MPH.          S 3-6 MPH.
TRANSPORT WINDS               W 5-9 MPH.          W 5-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI MAY 8         GOOD.
OUTLOOK FOR SAT MAY 9         FAIR.

VENTILATION INDEX (CATEGORY)  79 (POOR).          247 (POOR).
OUTLOOK FOR FRI MAY 8         879 (GOOD).
OUTLOOK FOR SAT MAY 9         194 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 1-3 MPH.         NW 7-12 MPH.
TRANSPORT WINDS               W 5-9 MPH.          NW 9-12 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI MAY 8         GOOD.
OUTLOOK FOR SAT MAY 9         FAIR.

VENTILATION INDEX (CATEGORY)  120 (POOR).         440 (FAIR).
OUTLOOK FOR FRI MAY 8         740 (GOOD).
OUTLOOK FOR SAT MAY 9         215 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SW 7-20 MPH.        W 9-12 MPH.
TRANSPORT WINDS               SW 11-19 MPH.       SW 9-12 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           FAIR.               FAIR.
OUTLOOK FOR FRI MAY 8         GOOD.
OUTLOOK FOR SAT MAY 9         FAIR.

VENTILATION INDEX (CATEGORY)  185 (POOR).         433 (FAIR).
OUTLOOK FOR FRI MAY 8         926 (GOOD).
OUTLOOK FOR SAT MAY 9         238 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      328 (FAIR)
ELLENSBURG    381 (FAIR)
GOLDENDALE    425 (FAIR)
TRI-CITIES    377 (FAIR)
WALLA WALLA   351 (FAIR)
YAKIMA        223 (POOR)
BEND          564 (FAIR)
PRINEVILLE    669 (GOOD)
ENTERPRISE    452 (FAIR)
HERMISTON     405 (FAIR)
JOHN DAY      780 (GOOD)
LA GRANDE     504 (FAIR)
MADRAS        403 (FAIR)
MEACHAM       403 (FAIR)
PENDLETON     497 (FAIR)
REDMOND       680 (GOOD)
SENECA        882 (GOOD)
THE DALLES    461 (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.
$$