361
AUUS46 KPDT 181225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT FRI SEP 18 2026

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 3-11 MPH.         SW 4-9 MPH.
TRANSPORT WINDS               S 7-12 MPH.         W 5-9 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT SEP 19        POOR.
OUTLOOK FOR SUN SEP 20        POOR.

VENTILATION INDEX (CATEGORY)  67 (POOR).          247 (POOR).
OUTLOOK FOR SAT SEP 19        167 (POOR).
OUTLOOK FOR SUN SEP 20        102 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 0-5 MPH.         SE 1-5 MPH.
TRANSPORT WINDS               NW 4-8 MPH.         W 3-6 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SAT SEP 19        POOR.
OUTLOOK FOR SUN SEP 20        POOR.

VENTILATION INDEX (CATEGORY)  29 (POOR).          133 (POOR).
OUTLOOK FOR SAT SEP 19        160 (POOR).
OUTLOOK FOR SUN SEP 20        102 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 0-2 MPH.         NW 5-9 MPH.
TRANSPORT WINDS               NW 3-6 MPH.         N 8-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT SEP 19        FAIR.
OUTLOOK FOR SUN SEP 20        FAIR.

VENTILATION INDEX (CATEGORY)  31 (POOR).          294 (POOR).
OUTLOOK FOR SAT SEP 19        351 (FAIR).
OUTLOOK FOR SUN SEP 20        181 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 4-9 MPH.          W 5-6 MPH.
TRANSPORT WINDS               S 8-11 MPH.         W 6-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT SEP 19        POOR.
OUTLOOK FOR SUN SEP 20        FAIR.

VENTILATION INDEX (CATEGORY)  72 (POOR).          239 (POOR).
OUTLOOK FOR SAT SEP 19        169 (POOR).
OUTLOOK FOR SUN SEP 20        151 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      256 (POOR)
ELLENSBURG    187 (POOR)
GOLDENDALE    283 (POOR)
TRI-CITIES    168 (POOR)
WALLA WALLA   244 (POOR)
YAKIMA        135 (POOR)
BEND          332 (FAIR)
PRINEVILLE    252 (POOR)
ENTERPRISE    218 (POOR)
HERMISTON     255 (POOR)
JOHN DAY      338 (FAIR)
LA GRANDE     331 (FAIR)
MADRAS        247 (POOR)
MEACHAM       211 (POOR)
PENDLETON     330 (FAIR)
REDMOND       257 (POOR)
SENECA        491 (FAIR)
THE DALLES    410 (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.
$$