305
AUUS46 KPDT 251225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT FRI JUL 25 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 10-20 MPH.       SW 14-19 MPH.
TRANSPORT WINDS               SW 12-21 MPH.       W 16-20 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7500 FT MSL.
DISPERSION CATEGORY           FAIR.               GOOD.
OUTLOOK FOR SAT JUL 26        FAIR.
OUTLOOK FOR SUN JUL 27        FAIR.

VENTILATION INDEX (CATEGORY)  232 (POOR).         853 (GOOD).
OUTLOOK FOR SAT JUL 26        659 (GOOD).
OUTLOOK FOR SUN JUL 27        563 (FAIR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 4-8 MPH.          W 7-12 MPH.
TRANSPORT WINDS               NW 5-9 MPH.         W 10-13 MPH.
MIXING HEIGHT                 NEAR SURFACE.       9000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT JUL 26        FAIR.
OUTLOOK FOR SUN JUL 27        FAIR.

VENTILATION INDEX (CATEGORY)  91 (POOR).          642 (GOOD).
OUTLOOK FOR SAT JUL 26        364 (FAIR).
OUTLOOK FOR SUN JUL 27        360 (FAIR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 3-4 MPH.         NW 8-10 MPH.
TRANSPORT WINDS               SW 4-8 MPH.         W 11-14 MPH.
MIXING HEIGHT                 4000 FT MSL.        10500 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR SAT JUL 26        GOOD.
OUTLOOK FOR SUN JUL 27        GOOD.

VENTILATION INDEX (CATEGORY)  119 (POOR).         682 (GOOD).
OUTLOOK FOR SAT JUL 26        411 (FAIR).
OUTLOOK FOR SUN JUL 27        370 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 9-21 MPH.         W 13-18 MPH.
TRANSPORT WINDS               SW 12-20 MPH.       W 17-21 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7000 FT MSL.
DISPERSION CATEGORY           FAIR.               GOOD.
OUTLOOK FOR SAT JUL 26        FAIR.
OUTLOOK FOR SUN JUL 27        FAIR.

VENTILATION INDEX (CATEGORY)  294 (POOR).         873 (GOOD).
OUTLOOK FOR SAT JUL 26        561 (FAIR).
OUTLOOK FOR SUN JUL 27        399 (FAIR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      740 (GOOD)
ELLENSBURG    742 (GOOD)
GOLDENDALE    716 (GOOD)
TRI-CITIES    674 (GOOD)
WALLA WALLA   934 (GOOD)
YAKIMA        680 (GOOD)
BEND          681 (GOOD)
PRINEVILLE    672 (GOOD)
ENTERPRISE    724 (GOOD)
HERMISTON     957 (GOOD)
JOHN DAY      787 (GOOD)
LA GRANDE     777 (GOOD)
MADRAS        586 (FAIR)
MEACHAM       630 (GOOD)
PENDLETON    1010 (GOOD)
REDMOND       688 (GOOD)
SENECA        973 (GOOD)
THE DALLES    858 (GOOD)

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.
$$