621
AUUS46 KPDT 181225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT TUE AUG 18 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 6-16 MPH.         W 9-15 MPH.
TRANSPORT WINDS               SW 9-16 MPH.        W 13-17 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6500 FT MSL.
DISPERSION CATEGORY           FAIR.               FAIR.
OUTLOOK FOR WED AUG 19        FAIR.
OUTLOOK FOR THU AUG 20        POOR.

VENTILATION INDEX (CATEGORY)  126 (POOR).         615 (GOOD).
OUTLOOK FOR WED AUG 19        373 (FAIR).
OUTLOOK FOR THU AUG 20        169 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 2-8 MPH.          NW 3-7 MPH.
TRANSPORT WINDS               W 5-10 MPH.         W 6-11 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR WED AUG 19        FAIR.
OUTLOOK FOR THU AUG 20        FAIR.

VENTILATION INDEX (CATEGORY)  53 (POOR).          392 (FAIR).
OUTLOOK FOR WED AUG 19        217 (POOR).
OUTLOOK FOR THU AUG 20        153 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 0-2 MPH.          NW 8-10 MPH.
TRANSPORT WINDS               W 3-7 MPH.          W 13-14 MPH.
MIXING HEIGHT                 NEAR SURFACE.       10000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR WED AUG 19        GOOD.
OUTLOOK FOR THU AUG 20        GOOD.

VENTILATION INDEX (CATEGORY)  44 (POOR).          652 (GOOD).
OUTLOOK FOR WED AUG 19        382 (FAIR).
OUTLOOK FOR THU AUG 20        291 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 5-14 MPH.         W 10-14 MPH.
TRANSPORT WINDS               SW 9-16 MPH.        W 15-18 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7000 FT MSL.
DISPERSION CATEGORY           FAIR.               GOOD.
OUTLOOK FOR WED AUG 19        FAIR.
OUTLOOK FOR THU AUG 20        FAIR.

VENTILATION INDEX (CATEGORY)  137 (POOR).         646 (GOOD).
OUTLOOK FOR WED AUG 19        363 (FAIR).
OUTLOOK FOR THU AUG 20        194 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      452 (FAIR)
ELLENSBURG    801 (GOOD)
GOLDENDALE    545 (FAIR)
TRI-CITIES    561 (FAIR)
WALLA WALLA   671 (GOOD)
YAKIMA        469 (FAIR)
BEND          549 (FAIR)
PRINEVILLE    529 (FAIR)
ENTERPRISE    808 (GOOD)
HERMISTON     683 (GOOD)
JOHN DAY      770 (GOOD)
LA GRANDE     691 (GOOD)
MADRAS        407 (FAIR)
MEACHAM       537 (FAIR)
PENDLETON     682 (GOOD)
REDMOND       601 (GOOD)
SENECA        893 (GOOD)
THE DALLES    537 (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.
$$