417
AUUS46 KPDT 311225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT THU JUL 31 2025

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SW 5-13 MPH.        W 9-13 MPH.
TRANSPORT WINDS               SW 10-17 MPH.       W 10-13 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7500 FT MSL.
DISPERSION CATEGORY           FAIR.               FAIR.
OUTLOOK FOR FRI AUG 1         FAIR.
OUTLOOK FOR SAT AUG 2         GOOD.

VENTILATION INDEX (CATEGORY)  133 (POOR).         503 (FAIR).
OUTLOOK FOR FRI AUG 1         407 (FAIR).
OUTLOOK FOR SAT AUG 2         597 (FAIR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 4-8 MPH.         NW 7-10 MPH.
TRANSPORT WINDS               NW 7-13 MPH.        NW 8-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       9500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI AUG 1         FAIR.
OUTLOOK FOR SAT AUG 2         FAIR.

VENTILATION INDEX (CATEGORY)  108 (POOR).         515 (FAIR).
OUTLOOK FOR FRI AUG 1         266 (POOR).
OUTLOOK FOR SAT AUG 2         352 (FAIR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 2-6 MPH.         NW 8-10 MPH.
TRANSPORT WINDS               NW 5-9 MPH.         NW 8-10 MPH.
MIXING HEIGHT                 4000 FT MSL.        10000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR FRI AUG 1         FAIR.
OUTLOOK FOR SAT AUG 2         GOOD.

VENTILATION INDEX (CATEGORY)  125 (POOR).         554 (FAIR).
OUTLOOK FOR FRI AUG 1         270 (POOR).
OUTLOOK FOR SAT AUG 2         694 (GOOD).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 5-10 MPH.         W 8-11 MPH.
TRANSPORT WINDS               SW 11-16 MPH.       W 9-11 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6500 FT MSL.
DISPERSION CATEGORY           FAIR.               FAIR.
OUTLOOK FOR FRI AUG 1         FAIR.
OUTLOOK FOR SAT AUG 2         GOOD.

VENTILATION INDEX (CATEGORY)  155 (POOR).         457 (FAIR).
OUTLOOK FOR FRI AUG 1         384 (FAIR).
OUTLOOK FOR SAT AUG 2         651 (GOOD).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      395 (FAIR)
ELLENSBURG    766 (GOOD)
GOLDENDALE    451 (FAIR)
TRI-CITIES    477 (FAIR)
WALLA WALLA   393 (FAIR)
YAKIMA        497 (FAIR)
BEND          402 (FAIR)
PRINEVILLE    543 (FAIR)
ENTERPRISE    493 (FAIR)
HERMISTON     517 (FAIR)
JOHN DAY      455 (FAIR)
LA GRANDE     574 (FAIR)
MADRAS        520 (FAIR)
MEACHAM       424 (FAIR)
PENDLETON     562 (FAIR)
REDMOND       575 (FAIR)
SENECA        465 (FAIR)
THE DALLES    520 (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.
$$