643
AUUS46 KPDT 201225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT WED AUG 20 2025

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 5-13 MPH.         W 8-11 MPH.
TRANSPORT WINDS               SW 8-14 MPH.        W 9-12 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR THU AUG 21        FAIR.
OUTLOOK FOR FRI AUG 22        FAIR.

VENTILATION INDEX (CATEGORY)  132 (POOR).         474 (FAIR).
OUTLOOK FOR THU AUG 21        206 (POOR).
OUTLOOK FOR FRI AUG 22        264 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 4-8 MPH.          NW 4-8 MPH.
TRANSPORT WINDS               NW 5-10 MPH.        W 6-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       9000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR THU AUG 21        POOR.
OUTLOOK FOR FRI AUG 22        FAIR.

VENTILATION INDEX (CATEGORY)  90 (POOR).          401 (FAIR).
OUTLOOK FOR THU AUG 21        185 (POOR).
OUTLOOK FOR FRI AUG 22        388 (FAIR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 2-6 MPH.         NW 9-12 MPH.
TRANSPORT WINDS               NW 4-8 MPH.         NW 10-12 MPH.
MIXING HEIGHT                 4000 FT MSL.        9500 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR THU AUG 21        GOOD.
OUTLOOK FOR FRI AUG 22        GOOD.

VENTILATION INDEX (CATEGORY)  125 (POOR).         520 (FAIR).
OUTLOOK FOR THU AUG 21        270 (POOR).
OUTLOOK FOR FRI AUG 22        257 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 5-14 MPH.         W 9-13 MPH.
TRANSPORT WINDS               SW 9-16 MPH.        W 10-13 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6500 FT MSL.
DISPERSION CATEGORY           FAIR.               FAIR.
OUTLOOK FOR THU AUG 21        FAIR.
OUTLOOK FOR FRI AUG 22        FAIR.

VENTILATION INDEX (CATEGORY)  163 (POOR).         512 (FAIR).
OUTLOOK FOR THU AUG 21        253 (POOR).
OUTLOOK FOR FRI AUG 22        236 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      682 (GOOD)
ELLENSBURG    800 (GOOD)
GOLDENDALE    655 (GOOD)
TRI-CITIES    419 (FAIR)
WALLA WALLA   499 (FAIR)
YAKIMA        383 (FAIR)
BEND          404 (FAIR)
PRINEVILLE    395 (FAIR)
ENTERPRISE    450 (FAIR)
HERMISTON     433 (FAIR)
JOHN DAY      541 (FAIR)
LA GRANDE     551 (FAIR)
MADRAS        365 (FAIR)
MEACHAM       408 (FAIR)
PENDLETON     584 (FAIR)
REDMOND       387 (FAIR)
SENECA        603 (GOOD)
THE DALLES    719 (GOOD)

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.
$$