778
AUUS46 KPDT 301225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT THU JUL 30 2026

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SW 7-16 MPH.        W 9-13 MPH.
TRANSPORT WINDS               SW 10-17 MPH.       W 10-14 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6000 FT MSL.
DISPERSION CATEGORY           FAIR.               FAIR.
OUTLOOK FOR FRI JUL 31        POOR.
OUTLOOK FOR SAT AUG 1         GOOD.

VENTILATION INDEX (CATEGORY)  146 (POOR).         489 (FAIR).
OUTLOOK FOR FRI JUL 31        189 (POOR).
OUTLOOK FOR SAT AUG 1         945 (GOOD).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 3-7 MPH.          SW 3-7 MPH.
TRANSPORT WINDS               NW 5-10 MPH.        SW 7-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI JUL 31        FAIR.
OUTLOOK FOR SAT AUG 1         GOOD.

VENTILATION INDEX (CATEGORY)  59 (POOR).          330 (FAIR).
OUTLOOK FOR FRI JUL 31        216 (POOR).
OUTLOOK FOR SAT AUG 1         902 (GOOD).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 2-5 MPH.         NW 6-8 MPH.
TRANSPORT WINDS               NW 5-9 MPH.         W 8-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI JUL 31        GOOD.
OUTLOOK FOR SAT AUG 1         FAIR.

VENTILATION INDEX (CATEGORY)  56 (POOR).          313 (FAIR).
OUTLOOK FOR FRI JUL 31        120 (POOR).
OUTLOOK FOR SAT AUG 1         400 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 5-14 MPH.         W 8-12 MPH.
TRANSPORT WINDS               SW 9-16 MPH.        W 9-12 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           FAIR.               FAIR.
OUTLOOK FOR FRI JUL 31        FAIR.
OUTLOOK FOR SAT AUG 1         GOOD.

VENTILATION INDEX (CATEGORY)  137 (POOR).         366 (FAIR).
OUTLOOK FOR FRI JUL 31        204 (POOR).
OUTLOOK FOR SAT AUG 1         786 (GOOD).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      397 (FAIR)
ELLENSBURG    726 (GOOD)
GOLDENDALE    511 (FAIR)
TRI-CITIES    504 (FAIR)
WALLA WALLA   414 (FAIR)
YAKIMA        239 (POOR)
BEND          381 (FAIR)
PRINEVILLE    333 (FAIR)
ENTERPRISE    444 (FAIR)
HERMISTON     513 (FAIR)
JOHN DAY      599 (FAIR)
LA GRANDE     355 (FAIR)
MADRAS        275 (POOR)
MEACHAM       239 (POOR)
PENDLETON     362 (FAIR)
REDMOND       330 (FAIR)
SENECA        826 (GOOD)
THE DALLES    497 (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.
$$