750
AUUS46 KPDT 211225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT FRI AUG 21 2026

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 E 1-4 MPH.          N 5-9 MPH.
TRANSPORT WINDS               W 3-5 MPH.          N 7-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT AUG 22        FAIR.
OUTLOOK FOR SUN AUG 23        FAIR.

VENTILATION INDEX (CATEGORY)  25 (POOR).          212 (POOR).
OUTLOOK FOR SAT AUG 22        589 (FAIR).
OUTLOOK FOR SUN AUG 23        486 (FAIR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 0-3 MPH.         E 3-6 MPH.
TRANSPORT WINDS               NW 4-8 MPH.         E 6-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT AUG 22        GOOD.
OUTLOOK FOR SUN AUG 23        FAIR.

VENTILATION INDEX (CATEGORY)  29 (POOR).          207 (POOR).
OUTLOOK FOR SAT AUG 22        853 (GOOD).
OUTLOOK FOR SUN AUG 23        260 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NE 0-2 MPH.         N 1-3 MPH.
TRANSPORT WINDS               NE 3-7 MPH.         SE 4-9 MPH.
MIXING HEIGHT                 NEAR SURFACE.       10000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR SAT AUG 22        GOOD.
OUTLOOK FOR SUN AUG 23        GOOD.

VENTILATION INDEX (CATEGORY)  28 (POOR).          216 (POOR).
OUTLOOK FOR SAT AUG 22        753 (GOOD).
OUTLOOK FOR SUN AUG 23        434 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 2-5 MPH.         N 6-9 MPH.
TRANSPORT WINDS               SE 4-8 MPH.         N 8-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT AUG 22        FAIR.
OUTLOOK FOR SUN AUG 23        FAIR.

VENTILATION INDEX (CATEGORY)  29 (POOR).          251 (POOR).
OUTLOOK FOR SAT AUG 22        457 (FAIR).
OUTLOOK FOR SUN AUG 23        448 (FAIR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      398 (FAIR)
ELLENSBURG    323 (FAIR)
GOLDENDALE    248 (POOR)
TRI-CITIES    224 (POOR)
WALLA WALLA   191 (POOR)
YAKIMA        203 (POOR)
BEND          691 (GOOD)
PRINEVILLE    453 (FAIR)
ENTERPRISE    498 (FAIR)
HERMISTON     217 (POOR)
JOHN DAY      623 (GOOD)
LA GRANDE     174 (POOR)
MADRAS        134 (POOR)
MEACHAM       242 (POOR)
PENDLETON     228 (POOR)
REDMOND       441 (FAIR)
SENECA        946 (GOOD)
THE DALLES     71 (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.
$$