818
AUUS46 KPDT 081225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT WED OCT  8 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 4-12 MPH.         W 7-10 MPH.
TRANSPORT WINDS               S 6-12 MPH.         W 7-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR THU OCT 9         POOR.
OUTLOOK FOR FRI OCT 10        FAIR.

VENTILATION INDEX (CATEGORY)  41 (POOR).          187 (POOR).
OUTLOOK FOR THU OCT 9         113 (POOR).
OUTLOOK FOR FRI OCT 10        379 (FAIR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 2-5 MPH.         S 5-9 MPH.
TRANSPORT WINDS               W 3-7 MPH.          SW 11-16 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR THU OCT 9         POOR.
OUTLOOK FOR FRI OCT 10        GOOD.

VENTILATION INDEX (CATEGORY)  33 (POOR).          376 (FAIR).
OUTLOOK FOR THU OCT 9         87 (POOR).
OUTLOOK FOR FRI OCT 10        478 (FAIR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 10-18 MPH.        S 16-20 MPH.
TRANSPORT WINDS               S 11-18 MPH.        S 22-25 MPH.
MIXING HEIGHT                 4000 FT MSL.        8000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR THU OCT 9         GOOD.
OUTLOOK FOR FRI OCT 10        GOOD.

VENTILATION INDEX (CATEGORY)  204 (POOR).         896 (GOOD).
OUTLOOK FOR THU OCT 9         720 (GOOD).
OUTLOOK FOR FRI OCT 10        1044 (GOOD).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 8-15 MPH.        NW 6-8 MPH.
TRANSPORT WINDS               S 10-16 MPH.        W 6-9 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4500 FT MSL.
DISPERSION CATEGORY           FAIR.               FAIR.
OUTLOOK FOR THU OCT 9         POOR.
OUTLOOK FOR FRI OCT 10        FAIR.

VENTILATION INDEX (CATEGORY)  81 (POOR).          205 (POOR).
OUTLOOK FOR THU OCT 9         82 (POOR).
OUTLOOK FOR FRI OCT 10        291 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      286 (POOR)
ELLENSBURG    259 (POOR)
GOLDENDALE    433 (FAIR)
TRI-CITIES    272 (POOR)
WALLA WALLA   178 (POOR)
YAKIMA        348 (FAIR)
BEND         1050 (GOOD)
PRINEVILLE   1050 (GOOD)
ENTERPRISE   1050 (GOOD)
HERMISTON     194 (POOR)
JOHN DAY     1050 (GOOD)
LA GRANDE     783 (GOOD)
MADRAS        749 (GOOD)
MEACHAM       549 (FAIR)
PENDLETON     191 (POOR)
REDMOND      1050 (GOOD)
SENECA       1050 (GOOD)
THE DALLES    467 (FAIR)

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.
$$