043
AUUS46 KPDT 281225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT THU AUG 28 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 4-9 MPH.         NW 7-9 MPH.
TRANSPORT WINDS               SE 4-8 MPH.         W 8-11 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI AUG 29        FAIR.
OUTLOOK FOR SAT AUG 30        FAIR.

VENTILATION INDEX (CATEGORY)  49 (POOR).          421 (FAIR).
OUTLOOK FOR FRI AUG 29        213 (POOR).
OUTLOOK FOR SAT AUG 30        279 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 2-5 MPH.         SE 4-8 MPH.
TRANSPORT WINDS               N 3-6 MPH.          SW 7-9 MPH.
MIXING HEIGHT                 NEAR SURFACE.       9500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI AUG 29        FAIR.
OUTLOOK FOR SAT AUG 30        FAIR.

VENTILATION INDEX (CATEGORY)  37 (POOR).          356 (FAIR).
OUTLOOK FOR FRI AUG 29        227 (POOR).
OUTLOOK FOR SAT AUG 30        365 (FAIR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 3-6 MPH.          NW 5-6 MPH.
TRANSPORT WINDS               S 4-6 MPH.          W 10-12 MPH.
MIXING HEIGHT                 4000 FT MSL.        13000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR FRI AUG 29        GOOD.
OUTLOOK FOR SAT AUG 30        GOOD.

VENTILATION INDEX (CATEGORY)  70 (POOR).          741 (GOOD).
OUTLOOK FOR FRI AUG 29        373 (FAIR).
OUTLOOK FOR SAT AUG 30        520 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 4-9 MPH.         NW 7-10 MPH.
TRANSPORT WINDS               S 7-10 MPH.         W 9-12 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI AUG 29        FAIR.
OUTLOOK FOR SAT AUG 30        GOOD.

VENTILATION INDEX (CATEGORY)  82 (POOR).          542 (FAIR).
OUTLOOK FOR FRI AUG 29        306 (FAIR).
OUTLOOK FOR SAT AUG 30        211 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      384 (FAIR)
ELLENSBURG    460 (FAIR)
GOLDENDALE    457 (FAIR)
TRI-CITIES    254 (POOR)
WALLA WALLA   470 (FAIR)
YAKIMA        367 (FAIR)
BEND         1048 (GOOD)
PRINEVILLE    803 (GOOD)
ENTERPRISE    917 (GOOD)
HERMISTON     387 (FAIR)
JOHN DAY      784 (GOOD)
LA GRANDE     839 (GOOD)
MADRAS        590 (FAIR)
MEACHAM       654 (GOOD)
PENDLETON     493 (FAIR)
REDMOND       844 (GOOD)
SENECA        929 (GOOD)
THE DALLES    295 (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.
$$