041
AUUS46 KPDT 171325
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PST MON NOV 17 2025

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 2-6 MPH.         NW 5-7 MPH.
TRANSPORT WINDS               S 3-6 MPH.          SW 5-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       2000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR TUE NOV 18        FAIR.
OUTLOOK FOR WED NOV 19        POOR.

VENTILATION INDEX (CATEGORY)  27 (POOR).          52 (POOR).
OUTLOOK FOR TUE NOV 18        279 (POOR).
OUTLOOK FOR WED NOV 19        69 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 1-3 MPH.         SE 2-5 MPH.
TRANSPORT WINDS               NE 2-4 MPH.         SE 2-5 MPH.
MIXING HEIGHT                 NEAR SURFACE.       2500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR TUE NOV 18        POOR.
OUTLOOK FOR WED NOV 19        POOR.

VENTILATION INDEX (CATEGORY)  26 (POOR).          39 (POOR).
OUTLOOK FOR TUE NOV 18        113 (POOR).
OUTLOOK FOR WED NOV 19        71 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 2-4 MPH.          S 3-4 MPH.
TRANSPORT WINDS               S 6-6 MPH.          S 6-8 MPH.
MIXING HEIGHT                 4000 FT MSL.        5500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR TUE NOV 18        FAIR.
OUTLOOK FOR WED NOV 19        FAIR.

VENTILATION INDEX (CATEGORY)  65 (POOR).          175 (POOR).
OUTLOOK FOR TUE NOV 18        135 (POOR).
OUTLOOK FOR WED NOV 19        149 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 3-7 MPH.          NW 3-6 MPH.
TRANSPORT WINDS               S 6-8 MPH.          SW 4-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       3000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR TUE NOV 18        FAIR.
OUTLOOK FOR WED NOV 19        POOR.

VENTILATION INDEX (CATEGORY)  47 (POOR).          92 (POOR).
OUTLOOK FOR TUE NOV 18        284 (POOR).
OUTLOOK FOR WED NOV 19        97 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      143 (POOR)
ELLENSBURG     25 (POOR)
GOLDENDALE    147 (POOR)
TRI-CITIES     45 (POOR)
WALLA WALLA    54 (POOR)
YAKIMA         37 (POOR)
BEND          343 (FAIR)
PRINEVILLE    302 (FAIR)
ENTERPRISE     63 (POOR)
HERMISTON      40 (POOR)
JOHN DAY      285 (POOR)
LA GRANDE     154 (POOR)
MADRAS         89 (POOR)
MEACHAM       139 (POOR)
PENDLETON      47 (POOR)
REDMOND       260 (POOR)
SENECA        253 (POOR)
THE DALLES    243 (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.
$$