390
AUUS46 KPDT 261325
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PST WED NOV 26 2025

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 2-6 MPH.          N 3-6 MPH.
TRANSPORT WINDS               S 5-10 MPH.         NW 3-6 MPH.
MIXING HEIGHT                 NEAR SURFACE.       NEAR SURFACE.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR THU NOV 27        POOR.
OUTLOOK FOR FRI NOV 28        POOR.

VENTILATION INDEX (CATEGORY)  30 (POOR).          34 (POOR).
OUTLOOK FOR THU NOV 27        41 (POOR).
OUTLOOK FOR FRI NOV 28        97 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 1-3 MPH.          SE 2-5 MPH.
TRANSPORT WINDS               W 2-6 MPH.          E 2-5 MPH.
MIXING HEIGHT                 NEAR SURFACE.       2000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR THU NOV 27        POOR.
OUTLOOK FOR FRI NOV 28        POOR.

VENTILATION INDEX (CATEGORY)  26 (POOR).          30 (POOR).
OUTLOOK FOR THU NOV 27        50 (POOR).
OUTLOOK FOR FRI NOV 28        100 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 9-12 MPH.         S 6-8 MPH.
TRANSPORT WINDS               S 10-12 MPH.        S 10-13 MPH.
MIXING HEIGHT                 4000 FT MSL.        4000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR THU NOV 27        FAIR.
OUTLOOK FOR FRI NOV 28        FAIR.

VENTILATION INDEX (CATEGORY)  116 (POOR).         144 (POOR).
OUTLOOK FOR THU NOV 27        303 (FAIR).
OUTLOOK FOR FRI NOV 28        218 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 5-10 MPH.         S 3-6 MPH.
TRANSPORT WINDS               S 9-16 MPH.         S 4-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       2000 FT MSL.
DISPERSION CATEGORY           FAIR.               POOR.
OUTLOOK FOR THU NOV 27        POOR.
OUTLOOK FOR FRI NOV 28        POOR.

VENTILATION INDEX (CATEGORY)  63 (POOR).          61 (POOR).
OUTLOOK FOR THU NOV 27        60 (POOR).
OUTLOOK FOR FRI NOV 28        91 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM       61 (POOR)
ELLENSBURG     25 (POOR)
GOLDENDALE     25 (POOR)
TRI-CITIES     51 (POOR)
WALLA WALLA    35 (POOR)
YAKIMA         25 (POOR)
BEND           77 (POOR)
PRINEVILLE     32 (POOR)
ENTERPRISE     66 (POOR)
HERMISTON      25 (POOR)
JOHN DAY       84 (POOR)
LA GRANDE     106 (POOR)
MADRAS         44 (POOR)
MEACHAM        43 (POOR)
PENDLETON      25 (POOR)
REDMOND        46 (POOR)
SENECA         55 (POOR)
THE DALLES     27 (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.
$$