572
AUUS46 KPDT 261225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT FRI SEP 26 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.         SW 6-8 MPH.
TRANSPORT WINDS               SW 8-14 MPH.        SW 6-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT SEP 27        POOR.
OUTLOOK FOR SUN SEP 28        FAIR.

VENTILATION INDEX (CATEGORY)  78 (POOR).          256 (POOR).
OUTLOOK FOR SAT SEP 27        84 (POOR).
OUTLOOK FOR SUN SEP 28        133 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 3-7 MPH.         SE 4-8 MPH.
TRANSPORT WINDS               NW 4-8 MPH.         SW 4-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SAT SEP 27        POOR.
OUTLOOK FOR SUN SEP 28        FAIR.

VENTILATION INDEX (CATEGORY)  46 (POOR).          197 (POOR).
OUTLOOK FOR SAT SEP 27        96 (POOR).
OUTLOOK FOR SUN SEP 28        179 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NE 3-7 MPH.         NW 4-8 MPH.
TRANSPORT WINDS               W 4-7 MPH.          NW 7-9 MPH.
MIXING HEIGHT                 4000 FT MSL.        8000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT SEP 27        FAIR.
OUTLOOK FOR SUN SEP 28        GOOD.

VENTILATION INDEX (CATEGORY)  87 (POOR).          353 (FAIR).
OUTLOOK FOR SAT SEP 27        432 (FAIR).
OUTLOOK FOR SUN SEP 28        591 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 5-13 MPH.         W 5-11 MPH.
TRANSPORT WINDS               SW 9-15 MPH.        W 5-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4500 FT MSL.
DISPERSION CATEGORY           FAIR.               FAIR.
OUTLOOK FOR SAT SEP 27        POOR.
OUTLOOK FOR SUN SEP 28        FAIR.

VENTILATION INDEX (CATEGORY)  109 (POOR).         262 (POOR).
OUTLOOK FOR SAT SEP 27        123 (POOR).
OUTLOOK FOR SUN SEP 28        183 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      544 (FAIR)
ELLENSBURG    525 (FAIR)
GOLDENDALE    259 (POOR)
TRI-CITIES    284 (POOR)
WALLA WALLA   278 (POOR)
YAKIMA        180 (POOR)
BEND          196 (POOR)
PRINEVILLE    174 (POOR)
ENTERPRISE    332 (FAIR)
HERMISTON     179 (POOR)
JOHN DAY      375 (FAIR)
LA GRANDE     381 (FAIR)
MADRAS        127 (POOR)
MEACHAM       210 (POOR)
PENDLETON     240 (POOR)
REDMOND       141 (POOR)
SENECA        407 (FAIR)
THE DALLES    345 (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.
$$