093
AUUS46 KPDT 201225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT SUN SEP 20 2026

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 0-6 MPH.         N 3-7 MPH.
TRANSPORT WINDS               SE 3-7 MPH.         N 4-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR MON SEP 21        FAIR.
OUTLOOK FOR TUE SEP 22        FAIR.

VENTILATION INDEX (CATEGORY)  26 (POOR).          118 (POOR).
OUTLOOK FOR MON SEP 21        154 (POOR).
OUTLOOK FOR TUE SEP 22        312 (FAIR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 0-3 MPH.         E 2-6 MPH.
TRANSPORT WINDS               NW 2-5 MPH.         SE 5-6 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR MON SEP 21        FAIR.
OUTLOOK FOR TUE SEP 22        FAIR.

VENTILATION INDEX (CATEGORY)  25 (POOR).          133 (POOR).
OUTLOOK FOR MON SEP 21        155 (POOR).
OUTLOOK FOR TUE SEP 22        169 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 0-2 MPH.         SE 1-4 MPH.
TRANSPORT WINDS               SE 2-4 MPH.         S 5-6 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR MON SEP 21        GOOD.
OUTLOOK FOR TUE SEP 22        FAIR.

VENTILATION INDEX (CATEGORY)  25 (POOR).          184 (POOR).
OUTLOOK FOR MON SEP 21        397 (FAIR).
OUTLOOK FOR TUE SEP 22        225 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 3-8 MPH.         N 4-8 MPH.
TRANSPORT WINDS               SE 6-11 MPH.        N 4-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR MON SEP 21        FAIR.
OUTLOOK FOR TUE SEP 22        FAIR.

VENTILATION INDEX (CATEGORY)  36 (POOR).          99 (POOR).
OUTLOOK FOR MON SEP 21        201 (POOR).
OUTLOOK FOR TUE SEP 22        295 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      219 (POOR)
ELLENSBURG    169 (POOR)
GOLDENDALE    183 (POOR)
TRI-CITIES     84 (POOR)
WALLA WALLA   104 (POOR)
YAKIMA        152 (POOR)
BEND          396 (FAIR)
PRINEVILLE    433 (FAIR)
ENTERPRISE    211 (POOR)
HERMISTON      97 (POOR)
JOHN DAY      295 (POOR)
LA GRANDE     227 (POOR)
MADRAS        199 (POOR)
MEACHAM       177 (POOR)
PENDLETON     171 (POOR)
REDMOND       394 (FAIR)
SENECA        398 (FAIR)
THE DALLES    160 (POOR)

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.
$$