155
AUUS46 KPDT 181225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT MON AUG 18 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 3-10 MPH.         W 6-10 MPH.
TRANSPORT WINDS               SW 6-11 MPH.        W 8-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR TUE AUG 19        FAIR.
OUTLOOK FOR WED AUG 20        FAIR.

VENTILATION INDEX (CATEGORY)  90 (POOR).          356 (FAIR).
OUTLOOK FOR TUE AUG 19        238 (POOR).
OUTLOOK FOR WED AUG 20        422 (FAIR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 2-5 MPH.         SW 7-12 MPH.
TRANSPORT WINDS               NW 4-7 MPH.         SW 9-16 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8500 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR TUE AUG 19        FAIR.
OUTLOOK FOR WED AUG 20        FAIR.

VENTILATION INDEX (CATEGORY)  65 (POOR).          554 (FAIR).
OUTLOOK FOR TUE AUG 19        229 (POOR).
OUTLOOK FOR WED AUG 20        345 (FAIR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 1-3 MPH.          NW 6-8 MPH.
TRANSPORT WINDS               SW 2-5 MPH.         SW 9-12 MPH.
MIXING HEIGHT                 4000 FT MSL.        9500 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR TUE AUG 19        GOOD.
OUTLOOK FOR WED AUG 20        GOOD.

VENTILATION INDEX (CATEGORY)  54 (POOR).          520 (FAIR).
OUTLOOK FOR TUE AUG 19        220 (POOR).
OUTLOOK FOR WED AUG 20        413 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 3-8 MPH.          NW 6-8 MPH.
TRANSPORT WINDS               S 7-10 MPH.         W 7-9 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR TUE AUG 19        FAIR.
OUTLOOK FOR WED AUG 20        FAIR.

VENTILATION INDEX (CATEGORY)  92 (POOR).          313 (FAIR).
OUTLOOK FOR TUE AUG 19        209 (POOR).
OUTLOOK FOR WED AUG 20        402 (FAIR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      580 (FAIR)
ELLENSBURG    549 (FAIR)
GOLDENDALE    640 (GOOD)
TRI-CITIES    354 (FAIR)
WALLA WALLA   318 (FAIR)
YAKIMA        634 (GOOD)
BEND          731 (GOOD)
PRINEVILLE    507 (FAIR)
ENTERPRISE   1050 (GOOD)
HERMISTON     359 (FAIR)
JOHN DAY     1050 (GOOD)
LA GRANDE     433 (FAIR)
MADRAS        371 (FAIR)
MEACHAM       223 (POOR)
PENDLETON     377 (FAIR)
REDMOND       457 (FAIR)
SENECA       1050 (GOOD)
THE DALLES    697 (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.
$$