780
AUUS46 KPDT 241225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT SUN AUG 24 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 2-6 MPH.          N 7-10 MPH.
TRANSPORT WINDS               SW 4-8 MPH.         N 7-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR MON AUG 25        FAIR.
OUTLOOK FOR TUE AUG 26        GOOD.

VENTILATION INDEX (CATEGORY)  34 (POOR).          217 (POOR).
OUTLOOK FOR MON AUG 25        231 (POOR).
OUTLOOK FOR TUE AUG 26        432 (FAIR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 3-7 MPH.         E 4-8 MPH.
TRANSPORT WINDS               NW 6-11 MPH.        NE 4-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR MON AUG 25        POOR.
OUTLOOK FOR TUE AUG 26        FAIR.

VENTILATION INDEX (CATEGORY)  60 (POOR).          323 (FAIR).
OUTLOOK FOR MON AUG 25        205 (POOR).
OUTLOOK FOR TUE AUG 26        259 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 1-3 MPH.         NW 6-8 MPH.
TRANSPORT WINDS               N 2-5 MPH.          NW 7-9 MPH.
MIXING HEIGHT                 4000 FT MSL.        13000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR MON AUG 25        GOOD.
OUTLOOK FOR TUE AUG 26        GOOD.

VENTILATION INDEX (CATEGORY)  34 (POOR).          406 (FAIR).
OUTLOOK FOR MON AUG 25        490 (FAIR).
OUTLOOK FOR TUE AUG 26        374 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 3-7 MPH.          NW 6-8 MPH.
TRANSPORT WINDS               S 5-7 MPH.          N 6-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR MON AUG 25        FAIR.
OUTLOOK FOR TUE AUG 26        FAIR.

VENTILATION INDEX (CATEGORY)  34 (POOR).          214 (POOR).
OUTLOOK FOR MON AUG 25        303 (FAIR).
OUTLOOK FOR TUE AUG 26        371 (FAIR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      321 (FAIR)
ELLENSBURG    257 (POOR)
GOLDENDALE    334 (FAIR)
TRI-CITIES    275 (POOR)
WALLA WALLA   163 (POOR)
YAKIMA        278 (POOR)
BEND          115 (POOR)
PRINEVILLE    266 (POOR)
ENTERPRISE    573 (FAIR)
HERMISTON     210 (POOR)
JOHN DAY      362 (FAIR)
LA GRANDE     425 (FAIR)
MADRAS        238 (POOR)
MEACHAM       204 (POOR)
PENDLETON     221 (POOR)
REDMOND       141 (POOR)
SENECA        499 (FAIR)
THE DALLES    242 (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.
$$