239
AUUS46 KPDT 031225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT WED SEP  3 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 2-6 MPH.         NW 5-9 MPH.
TRANSPORT WINDS               S 3-6 MPH.          NW 6-9 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR THU SEP 4         FAIR.
OUTLOOK FOR FRI SEP 5         FAIR.

VENTILATION INDEX (CATEGORY)  26 (POOR).          186 (POOR).
OUTLOOK FOR THU SEP 4         253 (POOR).
OUTLOOK FOR FRI SEP 5         218 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 3-7 MPH.         SE 3-6 MPH.
TRANSPORT WINDS               NW 5-9 MPH.         NE 5-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR THU SEP 4         POOR.
OUTLOOK FOR FRI SEP 5         FAIR.

VENTILATION INDEX (CATEGORY)  42 (POOR).          228 (POOR).
OUTLOOK FOR THU SEP 4         141 (POOR).
OUTLOOK FOR FRI SEP 5         337 (FAIR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 3-4 MPH.         NW 6-8 MPH.
TRANSPORT WINDS               N 3-6 MPH.          NW 6-8 MPH.
MIXING HEIGHT                 4000 FT MSL.        14000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR THU SEP 4         GOOD.
OUTLOOK FOR FRI SEP 5         GOOD.

VENTILATION INDEX (CATEGORY)  44 (POOR).          342 (FAIR).
OUTLOOK FOR THU SEP 4         342 (FAIR).
OUTLOOK FOR FRI SEP 5         439 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 3-7 MPH.         NW 7-9 MPH.
TRANSPORT WINDS               SE 4-7 MPH.         NW 7-9 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR THU SEP 4         FAIR.
OUTLOOK FOR FRI SEP 5         FAIR.

VENTILATION INDEX (CATEGORY)  30 (POOR).          237 (POOR).
OUTLOOK FOR THU SEP 4         259 (POOR).
OUTLOOK FOR FRI SEP 5         267 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      333 (FAIR)
ELLENSBURG    341 (FAIR)
GOLDENDALE    267 (POOR)
TRI-CITIES    140 (POOR)
WALLA WALLA   206 (POOR)
YAKIMA        264 (POOR)
BEND          547 (FAIR)
PRINEVILLE    506 (FAIR)
ENTERPRISE    389 (FAIR)
HERMISTON     147 (POOR)
JOHN DAY      300 (POOR)
LA GRANDE     330 (FAIR)
MADRAS        340 (FAIR)
MEACHAM       250 (POOR)
PENDLETON     249 (POOR)
REDMOND       540 (FAIR)
SENECA        241 (POOR)
THE DALLES    177 (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.
$$