671
AUUS46 KPDT 151225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT WED OCT 15 2025

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SW 2-6 MPH.         W 5-7 MPH.
TRANSPORT WINDS               SW 4-7 MPH.         W 5-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR THU OCT 16        FAIR.
OUTLOOK FOR FRI OCT 17        FAIR.

VENTILATION INDEX (CATEGORY)  31 (POOR).          125 (POOR).
OUTLOOK FOR THU OCT 16        284 (POOR).
OUTLOOK FOR FRI OCT 17        536 (FAIR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 3-7 MPH.         S 3-5 MPH.
TRANSPORT WINDS               NW 6-9 MPH.         W 3-5 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR THU OCT 16        POOR.
OUTLOOK FOR FRI OCT 17        FAIR.

VENTILATION INDEX (CATEGORY)  35 (POOR).          96 (POOR).
OUTLOOK FOR THU OCT 16        73 (POOR).
OUTLOOK FOR FRI OCT 17        276 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 4-9 MPH.         NW 9-12 MPH.
TRANSPORT WINDS               NW 8-11 MPH.        NW 11-15 MPH.
MIXING HEIGHT                 4000 FT MSL.        6500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR THU OCT 16        FAIR.
OUTLOOK FOR FRI OCT 17        FAIR.

VENTILATION INDEX (CATEGORY)  105 (POOR).         373 (FAIR).
OUTLOOK FOR THU OCT 16        217 (POOR).
OUTLOOK FOR FRI OCT 17        474 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 2-6 MPH.          W 4-8 MPH.
TRANSPORT WINDS               S 4-7 MPH.          W 5-9 MPH.
MIXING HEIGHT                 NEAR SURFACE.       3500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR THU OCT 16        FAIR.
OUTLOOK FOR FRI OCT 17        FAIR.

VENTILATION INDEX (CATEGORY)  37 (POOR).          146 (POOR).
OUTLOOK FOR THU OCT 16        369 (FAIR).
OUTLOOK FOR FRI OCT 17        616 (GOOD).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      144 (POOR)
ELLENSBURG     96 (POOR)
GOLDENDALE    134 (POOR)
TRI-CITIES    110 (POOR)
WALLA WALLA   139 (POOR)
YAKIMA         75 (POOR)
BEND          166 (POOR)
PRINEVILLE    134 (POOR)
ENTERPRISE    259 (POOR)
HERMISTON     107 (POOR)
JOHN DAY      296 (POOR)
LA GRANDE     343 (FAIR)
MADRAS         78 (POOR)
MEACHAM       128 (POOR)
PENDLETON     127 (POOR)
REDMOND       127 (POOR)
SENECA        369 (FAIR)
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.
$$