154
AUUS46 KPDT 031225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT FRI OCT  3 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 2-6 MPH.         W 7-10 MPH.
TRANSPORT WINDS               W 4-8 MPH.          W 7-9 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT OCT 4         FAIR.
OUTLOOK FOR SUN OCT 5         GOOD.

VENTILATION INDEX (CATEGORY)  42 (POOR).          291 (POOR).
OUTLOOK FOR SAT OCT 4         394 (FAIR).
OUTLOOK FOR SUN OCT 5         440 (FAIR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 3-7 MPH.         W 4-8 MPH.
TRANSPORT WINDS               NW 5-9 MPH.         W 6-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT OCT 4         FAIR.
OUTLOOK FOR SUN OCT 5         GOOD.

VENTILATION INDEX (CATEGORY)  49 (POOR).          254 (POOR).
OUTLOOK FOR SAT OCT 4         419 (FAIR).
OUTLOOK FOR SUN OCT 5         688 (GOOD).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 7-14 MPH.        NW 10-13 MPH.
TRANSPORT WINDS               NW 8-14 MPH.        N 10-14 MPH.
MIXING HEIGHT                 4000 FT MSL.        8000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT OCT 4         FAIR.
OUTLOOK FOR SUN OCT 5         GOOD.

VENTILATION INDEX (CATEGORY)  140 (POOR).         465 (FAIR).
OUTLOOK FOR SAT OCT 4         431 (FAIR).
OUTLOOK FOR SUN OCT 5         552 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SW 2-6 MPH.         W 6-11 MPH.
TRANSPORT WINDS               SW 4-7 MPH.         W 6-11 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT OCT 4         FAIR.
OUTLOOK FOR SUN OCT 5         FAIR.

VENTILATION INDEX (CATEGORY)  55 (POOR).          280 (POOR).
OUTLOOK FOR SAT OCT 4         406 (FAIR).
OUTLOOK FOR SUN OCT 5         351 (FAIR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      553 (FAIR)
ELLENSBURG    616 (GOOD)
GOLDENDALE    468 (FAIR)
TRI-CITIES    281 (POOR)
WALLA WALLA   248 (POOR)
YAKIMA        237 (POOR)
BEND          313 (FAIR)
PRINEVILLE    366 (FAIR)
ENTERPRISE    215 (POOR)
HERMISTON     238 (POOR)
JOHN DAY      514 (FAIR)
LA GRANDE     473 (FAIR)
MADRAS        280 (POOR)
MEACHAM       271 (POOR)
PENDLETON     303 (FAIR)
REDMOND       334 (FAIR)
SENECA        479 (FAIR)
THE DALLES    572 (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.
$$