311
AUUS46 KPDT 131225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT THU AUG 13 2026

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 4-9 MPH.          N 5-9 MPH.
TRANSPORT WINDS               W 6-10 MPH.         N 6-9 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI AUG 14        FAIR.
OUTLOOK FOR SAT AUG 15        POOR.

VENTILATION INDEX (CATEGORY)  84 (POOR).          381 (FAIR).
OUTLOOK FOR FRI AUG 14        419 (FAIR).
OUTLOOK FOR SAT AUG 15        197 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 1-4 MPH.         E 2-6 MPH.
TRANSPORT WINDS               NW 5-10 MPH.        NE 4-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       9500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI AUG 14        POOR.
OUTLOOK FOR SAT AUG 15        FAIR.

VENTILATION INDEX (CATEGORY)  73 (POOR).          353 (FAIR).
OUTLOOK FOR FRI AUG 14        250 (POOR).
OUTLOOK FOR SAT AUG 15        236 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 2-6 MPH.         NW 8-10 MPH.
TRANSPORT WINDS               NW 4-8 MPH.         NW 9-11 MPH.
MIXING HEIGHT                 NEAR SURFACE.       9500 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR FRI AUG 14        GOOD.
OUTLOOK FOR SAT AUG 15        GOOD.

VENTILATION INDEX (CATEGORY)  66 (POOR).          480 (FAIR).
OUTLOOK FOR FRI AUG 14        338 (FAIR).
OUTLOOK FOR SAT AUG 15        443 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SW 4-10 MPH.        N 5-10 MPH.
TRANSPORT WINDS               SW 7-12 MPH.        NW 7-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI AUG 14        FAIR.
OUTLOOK FOR SAT AUG 15        FAIR.

VENTILATION INDEX (CATEGORY)  95 (POOR).          337 (FAIR).
OUTLOOK FOR FRI AUG 14        484 (FAIR).
OUTLOOK FOR SAT AUG 15        252 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      122 (POOR)
ELLENSBURG    249 (POOR)
GOLDENDALE    272 (POOR)
TRI-CITIES    448 (FAIR)
WALLA WALLA   272 (POOR)
YAKIMA        346 (FAIR)
BEND          421 (FAIR)
PRINEVILLE    502 (FAIR)
ENTERPRISE    463 (FAIR)
HERMISTON     383 (FAIR)
JOHN DAY      540 (FAIR)
LA GRANDE     487 (FAIR)
MADRAS        364 (FAIR)
MEACHAM       339 (FAIR)
PENDLETON     370 (FAIR)
REDMOND       482 (FAIR)
SENECA        623 (GOOD)
THE DALLES    245 (POOR)

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.
$$