246
AUUS46 KPDT 271325
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PST THU NOV 27 2025

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 2-6 MPH.          N 3-5 MPH.
TRANSPORT WINDS               NW 3-7 MPH.         E 3-6 MPH.
MIXING HEIGHT                 NEAR SURFACE.       NEAR SURFACE.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI NOV 28        POOR.
OUTLOOK FOR SAT NOV 29        POOR.

VENTILATION INDEX (CATEGORY)  27 (POOR).          32 (POOR).
OUTLOOK FOR FRI NOV 28        121 (POOR).
OUTLOOK FOR SAT NOV 29        79 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 1-4 MPH.         E 2-4 MPH.
TRANSPORT WINDS               NW 3-6 MPH.         SE 3-6 MPH.
MIXING HEIGHT                 NEAR SURFACE.       2000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI NOV 28        POOR.
OUTLOOK FOR SAT NOV 29        POOR.

VENTILATION INDEX (CATEGORY)  27 (POOR).          46 (POOR).
OUTLOOK FOR FRI NOV 28        95 (POOR).
OUTLOOK FOR SAT NOV 29        87 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 7-13 MPH.        S 8-10 MPH.
TRANSPORT WINDS               S 10-17 MPH.        S 10-13 MPH.
MIXING HEIGHT                 4000 FT MSL.        4000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI NOV 28        FAIR.
OUTLOOK FOR SAT NOV 29        FAIR.

VENTILATION INDEX (CATEGORY)  134 (POOR).         172 (POOR).
OUTLOOK FOR FRI NOV 28        253 (POOR).
OUTLOOK FOR SAT NOV 29        168 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 2-6 MPH.          S 3-6 MPH.
TRANSPORT WINDS               S 4-9 MPH.          S 6-11 MPH.
MIXING HEIGHT                 NEAR SURFACE.       NEAR SURFACE.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI NOV 28        POOR.
OUTLOOK FOR SAT NOV 29        POOR.

VENTILATION INDEX (CATEGORY)  34 (POOR).          55 (POOR).
OUTLOOK FOR FRI NOV 28        94 (POOR).
OUTLOOK FOR SAT NOV 29        50 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      191 (POOR)
ELLENSBURG     58 (POOR)
GOLDENDALE     76 (POOR)
TRI-CITIES     31 (POOR)
WALLA WALLA    34 (POOR)
YAKIMA         41 (POOR)
BEND          862 (GOOD)
PRINEVILLE    528 (FAIR)
ENTERPRISE     85 (POOR)
HERMISTON      28 (POOR)
JOHN DAY      154 (POOR)
LA GRANDE     133 (POOR)
MADRAS        252 (POOR)
MEACHAM        56 (POOR)
PENDLETON      47 (POOR)
REDMOND       506 (FAIR)
SENECA        287 (POOR)
THE DALLES    103 (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.
$$