146
AUUS46 KPDT 301225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT SAT AUG 30 2025

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 4-9 MPH.          N 4-7 MPH.
TRANSPORT WINDS               S 6-11 MPH.         W 4-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SUN AUG 31        FAIR.
OUTLOOK FOR MON SEP 1         FAIR.

VENTILATION INDEX (CATEGORY)  53 (POOR).          179 (POOR).
OUTLOOK FOR SUN AUG 31        151 (POOR).
OUTLOOK FOR MON SEP 1         187 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 3-7 MPH.         E 3-6 MPH.
TRANSPORT WINDS               NW 5-9 MPH.         S 4-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SUN AUG 31        FAIR.
OUTLOOK FOR MON SEP 1         POOR.

VENTILATION INDEX (CATEGORY)  43 (POOR).          207 (POOR).
OUTLOOK FOR SUN AUG 31        202 (POOR).
OUTLOOK FOR MON SEP 1         173 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 2-4 MPH.         S 3-5 MPH.
TRANSPORT WINDS               S 2-4 MPH.          SW 11-12 MPH.
MIXING HEIGHT                 4000 FT MSL.        13500 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR SUN AUG 31        GOOD.
OUTLOOK FOR MON SEP 1         GOOD.

VENTILATION INDEX (CATEGORY)  38 (POOR).          871 (GOOD).
OUTLOOK FOR SUN AUG 31        1050 (GOOD).
OUTLOOK FOR MON SEP 1         977 (GOOD).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 4-9 MPH.          N 5-6 MPH.
TRANSPORT WINDS               S 6-11 MPH.         SW 6-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SUN AUG 31        FAIR.
OUTLOOK FOR MON SEP 1         FAIR.

VENTILATION INDEX (CATEGORY)  57 (POOR).          286 (POOR).
OUTLOOK FOR SUN AUG 31        293 (POOR).
OUTLOOK FOR MON SEP 1         155 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      371 (FAIR)
ELLENSBURG    404 (FAIR)
GOLDENDALE    314 (FAIR)
TRI-CITIES    129 (POOR)
WALLA WALLA   216 (POOR)
YAKIMA        285 (POOR)
BEND          924 (GOOD)
PRINEVILLE    645 (GOOD)
ENTERPRISE    710 (GOOD)
HERMISTON     114 (POOR)
JOHN DAY     1050 (GOOD)
LA GRANDE     772 (GOOD)
MADRAS        365 (FAIR)
MEACHAM       656 (GOOD)
PENDLETON     241 (POOR)
REDMOND       602 (GOOD)
SENECA       1050 (GOOD)
THE DALLES    234 (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.
$$