514
AUUS46 KPDT 291225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT TUE SEP 29 2026

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 6-18 MPH.         SW 16-22 MPH.
TRANSPORT WINDS               SW 10-20 MPH.       SW 20-25 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           FAIR.               GOOD.
OUTLOOK FOR WED SEP 30        POOR.
OUTLOOK FOR THU OCT 1         FAIR.

VENTILATION INDEX (CATEGORY)  125 (POOR).         700 (GOOD).
OUTLOOK FOR WED SEP 30        240 (POOR).
OUTLOOK FOR THU OCT 1         149 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 0-9 MPH.         W 9-16 MPH.
TRANSPORT WINDS               SW 3-11 MPH.        W 14-19 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR WED SEP 30        POOR.
OUTLOOK FOR THU OCT 1         POOR.

VENTILATION INDEX (CATEGORY)  37 (POOR).          457 (FAIR).
OUTLOOK FOR WED SEP 30        122 (POOR).
OUTLOOK FOR THU OCT 1         105 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 2-5 MPH.          NW 4-9 MPH.
TRANSPORT WINDS               S 4-7 MPH.          W 11-15 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR WED SEP 30        FAIR.
OUTLOOK FOR THU OCT 1         FAIR.

VENTILATION INDEX (CATEGORY)  34 (POOR).          435 (FAIR).
OUTLOOK FOR WED SEP 30        342 (FAIR).
OUTLOOK FOR THU OCT 1         162 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 6-14 MPH.         W 14-21 MPH.
TRANSPORT WINDS               S 10-19 MPH.        W 18-25 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           FAIR.               GOOD.
OUTLOOK FOR WED SEP 30        FAIR.
OUTLOOK FOR THU OCT 1         FAIR.

VENTILATION INDEX (CATEGORY)  123 (POOR).         696 (GOOD).
OUTLOOK FOR WED SEP 30        315 (FAIR).
OUTLOOK FOR THU OCT 1         168 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      443 (FAIR)
ELLENSBURG    341 (FAIR)
GOLDENDALE    571 (FAIR)
TRI-CITIES    573 (FAIR)
WALLA WALLA   801 (GOOD)
YAKIMA        378 (FAIR)
BEND          222 (POOR)
PRINEVILLE    312 (FAIR)
ENTERPRISE    447 (FAIR)
HERMISTON     779 (GOOD)
JOHN DAY      312 (FAIR)
LA GRANDE     517 (FAIR)
MADRAS        304 (FAIR)
MEACHAM       510 (FAIR)
PENDLETON     716 (GOOD)
REDMOND       314 (FAIR)
SENECA        380 (FAIR)
THE DALLES    484 (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.
$$