419
AUUS46 KPDT 161225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT WED SEP 16 2026

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 1-5 MPH.         N 7-11 MPH.
TRANSPORT WINDS               NW 3-8 MPH.         N 11-15 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR THU SEP 17        POOR.
OUTLOOK FOR FRI SEP 18        FAIR.

VENTILATION INDEX (CATEGORY)  32 (POOR).          328 (FAIR).
OUTLOOK FOR THU SEP 17        132 (POOR).
OUTLOOK FOR FRI SEP 18        269 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 1-4 MPH.         NE 6-11 MPH.
TRANSPORT WINDS               NW 6-11 MPH.        NE 11-16 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR THU SEP 17        POOR.
OUTLOOK FOR FRI SEP 18        POOR.

VENTILATION INDEX (CATEGORY)  56 (POOR).          470 (FAIR).
OUTLOOK FOR THU SEP 17        161 (POOR).
OUTLOOK FOR FRI SEP 18        108 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 7-14 MPH.        N 12-16 MPH.
TRANSPORT WINDS               N 10-16 MPH.        N 14-16 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR THU SEP 17        FAIR.
OUTLOOK FOR FRI SEP 18        FAIR.

VENTILATION INDEX (CATEGORY)  92 (POOR).          463 (FAIR).
OUTLOOK FOR THU SEP 17        65 (POOR).
OUTLOOK FOR FRI SEP 18        69 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 0-3 MPH.          N 7-10 MPH.
TRANSPORT WINDS               S 2-5 MPH.          NE 9-12 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR THU SEP 17        POOR.
OUTLOOK FOR FRI SEP 18        FAIR.

VENTILATION INDEX (CATEGORY)  26 (POOR).          236 (POOR).
OUTLOOK FOR THU SEP 17        121 (POOR).
OUTLOOK FOR FRI SEP 18        287 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      401 (FAIR)
ELLENSBURG    345 (FAIR)
GOLDENDALE    639 (GOOD)
TRI-CITIES    462 (FAIR)
WALLA WALLA   199 (POOR)
YAKIMA        544 (FAIR)
BEND          568 (FAIR)
PRINEVILLE    478 (FAIR)
ENTERPRISE    310 (FAIR)
HERMISTON     350 (FAIR)
JOHN DAY      499 (FAIR)
LA GRANDE     447 (FAIR)
MADRAS        710 (GOOD)
MEACHAM       231 (POOR)
PENDLETON     313 (FAIR)
REDMOND       590 (FAIR)
SENECA        664 (GOOD)
THE DALLES    530 (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.
$$