811
AUUS46 KPDT 071225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT TUE OCT  7 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 1-7 MPH.         N 3-6 MPH.
TRANSPORT WINDS               SE 3-7 MPH.         S 4-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       3500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR WED OCT 8         FAIR.
OUTLOOK FOR THU OCT 9         FAIR.

VENTILATION INDEX (CATEGORY)  27 (POOR).          86 (POOR).
OUTLOOK FOR WED OCT 8         289 (POOR).
OUTLOOK FOR THU OCT 9         138 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 1-3 MPH.         SE 4-7 MPH.
TRANSPORT WINDS               NW 3-6 MPH.         S 6-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR WED OCT 8         FAIR.
OUTLOOK FOR THU OCT 9         FAIR.

VENTILATION INDEX (CATEGORY)  30 (POOR).          146 (POOR).
OUTLOOK FOR WED OCT 8         227 (POOR).
OUTLOOK FOR THU OCT 9         144 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 5-11 MPH.        S 15-19 MPH.
TRANSPORT WINDS               S 6-11 MPH.         S 22-25 MPH.
MIXING HEIGHT                 4000 FT MSL.        7000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR WED OCT 8         GOOD.
OUTLOOK FOR THU OCT 9         GOOD.

VENTILATION INDEX (CATEGORY)  132 (POOR).         798 (GOOD).
OUTLOOK FOR WED OCT 8         853 (GOOD).
OUTLOOK FOR THU OCT 9         649 (GOOD).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 6-11 MPH.        NW 5-7 MPH.
TRANSPORT WINDS               SE 7-14 MPH.        S 8-13 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR WED OCT 8         FAIR.
OUTLOOK FOR THU OCT 9         FAIR.

VENTILATION INDEX (CATEGORY)  61 (POOR).          265 (POOR).
OUTLOOK FOR WED OCT 8         255 (POOR).
OUTLOOK FOR THU OCT 9         137 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      346 (FAIR)
ELLENSBURG    282 (POOR)
GOLDENDALE    178 (POOR)
TRI-CITIES     67 (POOR)
WALLA WALLA   175 (POOR)
YAKIMA        165 (POOR)
BEND          470 (FAIR)
PRINEVILLE    520 (FAIR)
ENTERPRISE    239 (POOR)
HERMISTON      25 (POOR)
JOHN DAY      555 (FAIR)
LA GRANDE     728 (GOOD)
MADRAS        386 (FAIR)
MEACHAM       475 (FAIR)
PENDLETON     147 (POOR)
REDMOND       472 (FAIR)
SENECA        501 (FAIR)
THE DALLES    186 (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.
$$