687
AUUS46 KPDT 171225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT FRI OCT 17 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 9-17 MPH.        W 18-25 MPH.
TRANSPORT WINDS               SW 9-17 MPH.        W 19-27 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           FAIR.               GOOD.
OUTLOOK FOR SAT OCT 18        POOR.
OUTLOOK FOR SUN OCT 19        GOOD.

VENTILATION INDEX (CATEGORY)  91 (POOR).          728 (GOOD).
OUTLOOK FOR SAT OCT 18        71 (POOR).
OUTLOOK FOR SUN OCT 19        1050 (GOOD).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 4-8 MPH.          W 12-16 MPH.
TRANSPORT WINDS               W 4-8 MPH.          NW 13-18 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT OCT 18        POOR.
OUTLOOK FOR SUN OCT 19        GOOD.

VENTILATION INDEX (CATEGORY)  44 (POOR).          495 (FAIR).
OUTLOOK FOR SAT OCT 18        90 (POOR).
OUTLOOK FOR SUN OCT 19        1035 (GOOD).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 5-7 MPH.          W 14-16 MPH.
TRANSPORT WINDS               S 5-9 MPH.          W 18-25 MPH.
MIXING HEIGHT                 4000 FT MSL.        8000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR SAT OCT 18        GOOD.
OUTLOOK FOR SUN OCT 19        GOOD.

VENTILATION INDEX (CATEGORY)  83 (POOR).          702 (GOOD).
OUTLOOK FOR SAT OCT 18        349 (FAIR).
OUTLOOK FOR SUN OCT 19        1049 (GOOD).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SW 8-18 MPH.        W 18-24 MPH.
TRANSPORT WINDS               SW 11-19 MPH.       W 23-26 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           FAIR.               GOOD.
OUTLOOK FOR SAT OCT 18        POOR.
OUTLOOK FOR SUN OCT 19        GOOD.

VENTILATION INDEX (CATEGORY)  136 (POOR).         819 (GOOD).
OUTLOOK FOR SAT OCT 18        113 (POOR).
OUTLOOK FOR SUN OCT 19        1049 (GOOD).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM     1014 (GOOD)
ELLENSBURG    887 (GOOD)
GOLDENDALE    741 (GOOD)
TRI-CITIES    644 (GOOD)
WALLA WALLA   766 (GOOD)
YAKIMA        479 (FAIR)
BEND          309 (FAIR)
PRINEVILLE    485 (FAIR)
ENTERPRISE    846 (GOOD)
HERMISTON     715 (GOOD)
JOHN DAY      680 (GOOD)
LA GRANDE     833 (GOOD)
MADRAS        368 (FAIR)
MEACHAM       647 (GOOD)
PENDLETON     997 (GOOD)
REDMOND       506 (FAIR)
SENECA        654 (GOOD)
THE DALLES    910 (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.
$$