166
AUUS46 KPDT 201225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT MON JUL 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 1-4 MPH.         N 3-6 MPH.
TRANSPORT WINDS               SW 3-6 MPH.         N 6-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       3500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR TUE JUL 21        FAIR.
OUTLOOK FOR WED JUL 22        POOR.

VENTILATION INDEX (CATEGORY)  29 (POOR).          153 (POOR).
OUTLOOK FOR TUE JUL 21        324 (FAIR).
OUTLOOK FOR WED JUL 22        335 (FAIR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 1-4 MPH.         SE 3-6 MPH.
TRANSPORT WINDS               NW 4-8 MPH.         SE 4-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR TUE JUL 21        POOR.
OUTLOOK FOR WED JUL 22        GOOD.

VENTILATION INDEX (CATEGORY)  41 (POOR).          172 (POOR).
OUTLOOK FOR TUE JUL 21        247 (POOR).
OUTLOOK FOR WED JUL 22        472 (FAIR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 N 1-3 MPH.          N 6-11 MPH.
TRANSPORT WINDS               N 4-8 MPH.          N 9-12 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR TUE JUL 21        GOOD.
OUTLOOK FOR WED JUL 22        GOOD.

VENTILATION INDEX (CATEGORY)  35 (POOR).          259 (POOR).
OUTLOOK FOR TUE JUL 21        435 (FAIR).
OUTLOOK FOR WED JUL 22        351 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 1-4 MPH.         N 3-6 MPH.
TRANSPORT WINDS               SE 3-6 MPH.         N 5-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR TUE JUL 21        FAIR.
OUTLOOK FOR WED JUL 22        FAIR.

VENTILATION INDEX (CATEGORY)  28 (POOR).          162 (POOR).
OUTLOOK FOR TUE JUL 21        374 (FAIR).
OUTLOOK FOR WED JUL 22        379 (FAIR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      485 (FAIR)
ELLENSBURG    346 (FAIR)
GOLDENDALE    177 (POOR)
TRI-CITIES    156 (POOR)
WALLA WALLA   119 (POOR)
YAKIMA        266 (POOR)
BEND          159 (POOR)
PRINEVILLE    208 (POOR)
ENTERPRISE    131 (POOR)
HERMISTON     143 (POOR)
JOHN DAY      340 (FAIR)
LA GRANDE     253 (POOR)
MADRAS        141 (POOR)
MEACHAM       198 (POOR)
PENDLETON     204 (POOR)
REDMOND       100 (POOR)
SENECA        516 (FAIR)
THE DALLES    169 (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.
$$