962
AUUS46 KPDT 311225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT SUN AUG 31 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 3-8 MPH.          NW 3-6 MPH.
TRANSPORT WINDS               S 3-7 MPH.          W 5-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR MON SEP 1         POOR.
OUTLOOK FOR TUE SEP 2         POOR.

VENTILATION INDEX (CATEGORY)  33 (POOR).          144 (POOR).
OUTLOOK FOR MON SEP 1         160 (POOR).
OUTLOOK FOR TUE SEP 2         148 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 2-6 MPH.         SE 4-5 MPH.
TRANSPORT WINDS               NW 5-9 MPH.         S 7-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR MON SEP 1         FAIR.
OUTLOOK FOR TUE SEP 2         FAIR.

VENTILATION INDEX (CATEGORY)  52 (POOR).          281 (POOR).
OUTLOOK FOR MON SEP 1         164 (POOR).
OUTLOOK FOR TUE SEP 2         209 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 E 6-12 MPH.         S 14-16 MPH.
TRANSPORT WINDS               SE 6-12 MPH.        S 20-20 MPH.
MIXING HEIGHT                 4000 FT MSL.        14000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR MON SEP 1         GOOD.
OUTLOOK FOR TUE SEP 2         GOOD.

VENTILATION INDEX (CATEGORY)  142 (POOR).         1050 (GOOD).
OUTLOOK FOR MON SEP 1         1002 (GOOD).
OUTLOOK FOR TUE SEP 2         621 (GOOD).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 4-9 MPH.         NW 5-7 MPH.
TRANSPORT WINDS               SE 5-10 MPH.        S 6-12 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR MON SEP 1         POOR.
OUTLOOK FOR TUE SEP 2         FAIR.

VENTILATION INDEX (CATEGORY)  54 (POOR).          253 (POOR).
OUTLOOK FOR MON SEP 1         127 (POOR).
OUTLOOK FOR TUE SEP 2         149 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      656 (GOOD)
ELLENSBURG    671 (GOOD)
GOLDENDALE    311 (FAIR)
TRI-CITIES    151 (POOR)
WALLA WALLA   132 (POOR)
YAKIMA        326 (FAIR)
BEND         1049 (GOOD)
PRINEVILLE    753 (GOOD)
ENTERPRISE   1050 (GOOD)
HERMISTON     147 (POOR)
JOHN DAY     1050 (GOOD)
LA GRANDE    1050 (GOOD)
MADRAS        428 (FAIR)
MEACHAM      1024 (GOOD)
PENDLETON     160 (POOR)
REDMOND       729 (GOOD)
SENECA       1050 (GOOD)
THE DALLES    388 (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.
$$