936
AUUS46 KPDT 091225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT THU OCT  9 2025

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SW 3-8 MPH.         N 6-8 MPH.
TRANSPORT WINDS               SW 4-9 MPH.         NW 6-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       3500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI OCT 10        GOOD.
OUTLOOK FOR SAT OCT 11        GOOD.

VENTILATION INDEX (CATEGORY)  43 (POOR).          114 (POOR).
OUTLOOK FOR FRI OCT 10        443 (FAIR).
OUTLOOK FOR SAT OCT 11        749 (GOOD).

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 4-8 MPH.         S 5-6 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI OCT 10        GOOD.
OUTLOOK FOR SAT OCT 11        FAIR.

VENTILATION INDEX (CATEGORY)  40 (POOR).          137 (POOR).
OUTLOOK FOR FRI OCT 10        781 (GOOD).
OUTLOOK FOR SAT OCT 11        611 (GOOD).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 E 5-10 MPH.         S 6-10 MPH.
TRANSPORT WINDS               SE 6-11 MPH.        S 18-20 MPH.
MIXING HEIGHT                 4000 FT MSL.        8500 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR FRI OCT 10        GOOD.
OUTLOOK FOR SAT OCT 11        GOOD.

VENTILATION INDEX (CATEGORY)  84 (POOR).          820 (GOOD).
OUTLOOK FOR FRI OCT 10        1050 (GOOD).
OUTLOOK FOR SAT OCT 11        522 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 4-9 MPH.          N 5-7 MPH.
TRANSPORT WINDS               S 5-10 MPH.         N 5-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       3000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI OCT 10        GOOD.
OUTLOOK FOR SAT OCT 11        GOOD.

VENTILATION INDEX (CATEGORY)  42 (POOR).          76 (POOR).
OUTLOOK FOR FRI OCT 10        444 (FAIR).
OUTLOOK FOR SAT OCT 11        728 (GOOD).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      272 (POOR)
ELLENSBURG    197 (POOR)
GOLDENDALE    141 (POOR)
TRI-CITIES    123 (POOR)
WALLA WALLA    85 (POOR)
YAKIMA        161 (POOR)
BEND          517 (FAIR)
PRINEVILLE    782 (GOOD)
ENTERPRISE    790 (GOOD)
HERMISTON     102 (POOR)
JOHN DAY     1050 (GOOD)
LA GRANDE     820 (GOOD)
MADRAS        199 (POOR)
MEACHAM       254 (POOR)
PENDLETON     135 (POOR)
REDMOND       362 (FAIR)
SENECA       1050 (GOOD)
THE DALLES    160 (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.
$$