403
AUUS46 KPDT 291225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT FRI AUG 29 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 3-7 MPH.          N 4-8 MPH.
TRANSPORT WINDS               SW 3-7 MPH.         NW 5-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SAT AUG 30        FAIR.
OUTLOOK FOR SUN AUG 31        FAIR.

VENTILATION INDEX (CATEGORY)  30 (POOR).          208 (POOR).
OUTLOOK FOR SAT AUG 30        163 (POOR).
OUTLOOK FOR SUN AUG 31        167 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 2-5 MPH.         SE 4-8 MPH.
TRANSPORT WINDS               NW 4-8 MPH.         SW 6-11 MPH.
MIXING HEIGHT                 NEAR SURFACE.       9000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT AUG 30        FAIR.
OUTLOOK FOR SUN AUG 31        FAIR.

VENTILATION INDEX (CATEGORY)  37 (POOR).          338 (FAIR).
OUTLOOK FOR SAT AUG 30        181 (POOR).
OUTLOOK FOR SUN AUG 31        215 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 2-5 MPH.         NE 4-5 MPH.
TRANSPORT WINDS               S 3-6 MPH.          W 8-10 MPH.
MIXING HEIGHT                 4000 FT MSL.        13500 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR SAT AUG 30        GOOD.
OUTLOOK FOR SUN AUG 31        GOOD.

VENTILATION INDEX (CATEGORY)  49 (POOR).          519 (FAIR).
OUTLOOK FOR SAT AUG 30        638 (GOOD).
OUTLOOK FOR SUN AUG 31        1031 (GOOD).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 4-8 MPH.         N 6-8 MPH.
TRANSPORT WINDS               SE 5-9 MPH.         NW 7-9 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT AUG 30        FAIR.
OUTLOOK FOR SUN AUG 31        FAIR.

VENTILATION INDEX (CATEGORY)  39 (POOR).          370 (FAIR).
OUTLOOK FOR SAT AUG 30        201 (POOR).
OUTLOOK FOR SUN AUG 31        421 (FAIR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      542 (FAIR)
ELLENSBURG    540 (FAIR)
GOLDENDALE    298 (POOR)
TRI-CITIES    113 (POOR)
WALLA WALLA   291 (POOR)
YAKIMA        474 (FAIR)
BEND          972 (GOOD)
PRINEVILLE    560 (FAIR)
ENTERPRISE    922 (GOOD)
HERMISTON     124 (POOR)
JOHN DAY      562 (FAIR)
LA GRANDE     429 (FAIR)
MADRAS        475 (FAIR)
MEACHAM       570 (FAIR)
PENDLETON     301 (FAIR)
REDMOND       679 (GOOD)
SENECA        583 (FAIR)
THE DALLES    154 (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.
$$