628
AUUS46 KPDT 211325
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PST FRI NOV 21 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 3-7 MPH.         W 3-6 MPH.
TRANSPORT WINDS               S 4-8 MPH.          SW 4-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       2000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SAT NOV 22        POOR.
OUTLOOK FOR SUN NOV 23        FAIR.

VENTILATION INDEX (CATEGORY)  28 (POOR).          63 (POOR).
OUTLOOK FOR SAT NOV 22        31 (POOR).
OUTLOOK FOR SUN NOV 23        94 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 1-4 MPH.          SE 2-4 MPH.
TRANSPORT WINDS               W 2-5 MPH.          S 2-4 MPH.
MIXING HEIGHT                 NEAR SURFACE.       2000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SAT NOV 22        POOR.
OUTLOOK FOR SUN NOV 23        FAIR.

VENTILATION INDEX (CATEGORY)  27 (POOR).          35 (POOR).
OUTLOOK FOR SAT NOV 22        30 (POOR).
OUTLOOK FOR SUN NOV 23        116 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 1-3 MPH.         SE 1-2 MPH.
TRANSPORT WINDS               SW 1-3 MPH.         SW 2-4 MPH.
MIXING HEIGHT                 4000 FT MSL.        5000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SAT NOV 22        GOOD.
OUTLOOK FOR SUN NOV 23        GOOD.

VENTILATION INDEX (CATEGORY)  31 (POOR).          71 (POOR).
OUTLOOK FOR SAT NOV 22        379 (FAIR).
OUTLOOK FOR SUN NOV 23        383 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 3-6 MPH.         W 2-5 MPH.
TRANSPORT WINDS               S 4-7 MPH.          SW 3-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       2500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SAT NOV 22        POOR.
OUTLOOK FOR SUN NOV 23        FAIR.

VENTILATION INDEX (CATEGORY)  33 (POOR).          76 (POOR).
OUTLOOK FOR SAT NOV 22        60 (POOR).
OUTLOOK FOR SUN NOV 23        114 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      182 (POOR)
ELLENSBURG     63 (POOR)
GOLDENDALE     55 (POOR)
TRI-CITIES     80 (POOR)
WALLA WALLA    79 (POOR)
YAKIMA         34 (POOR)
BEND           36 (POOR)
PRINEVILLE     64 (POOR)
ENTERPRISE     60 (POOR)
HERMISTON      34 (POOR)
JOHN DAY       70 (POOR)
LA GRANDE      76 (POOR)
MADRAS         63 (POOR)
MEACHAM        60 (POOR)
PENDLETON      52 (POOR)
REDMOND        63 (POOR)
SENECA         69 (POOR)
THE DALLES     33 (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.
$$