408
AUUS46 KPDT 181325
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PST TUE NOV 18 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 7-16 MPH.        SW 7-10 MPH.
TRANSPORT WINDS               SW 10-16 MPH.       W 7-12 MPH.
MIXING HEIGHT                 NEAR SURFACE.       3000 FT MSL.
DISPERSION CATEGORY           FAIR.               POOR.
OUTLOOK FOR WED NOV 19        POOR.
OUTLOOK FOR THU NOV 20        POOR.

VENTILATION INDEX (CATEGORY)  68 (POOR).          223 (POOR).
OUTLOOK FOR WED NOV 19        61 (POOR).
OUTLOOK FOR THU NOV 20        66 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 3-7 MPH.          W 2-5 MPH.
TRANSPORT WINDS               W 4-8 MPH.          NW 2-5 MPH.
MIXING HEIGHT                 NEAR SURFACE.       3000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR WED NOV 19        POOR.
OUTLOOK FOR THU NOV 20        POOR.

VENTILATION INDEX (CATEGORY)  31 (POOR).          61 (POOR).
OUTLOOK FOR WED NOV 19        82 (POOR).
OUTLOOK FOR THU NOV 20        57 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 2-4 MPH.          NW 4-5 MPH.
TRANSPORT WINDS               W 5-9 MPH.          NW 6-8 MPH.
MIXING HEIGHT                 4500 FT MSL.        5500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR WED NOV 19        FAIR.
OUTLOOK FOR THU NOV 20        FAIR.

VENTILATION INDEX (CATEGORY)  76 (POOR).          162 (POOR).
OUTLOOK FOR WED NOV 19        75 (POOR).
OUTLOOK FOR THU NOV 20        187 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SW 4-16 MPH.        W 5-11 MPH.
TRANSPORT WINDS               SW 10-19 MPH.       W 7-12 MPH.
MIXING HEIGHT                 NEAR SURFACE.       3500 FT MSL.
DISPERSION CATEGORY           FAIR.               POOR.
OUTLOOK FOR WED NOV 19        POOR.
OUTLOOK FOR THU NOV 20        POOR.

VENTILATION INDEX (CATEGORY)  98 (POOR).          247 (POOR).
OUTLOOK FOR WED NOV 19        62 (POOR).
OUTLOOK FOR THU NOV 20        79 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      441 (FAIR)
ELLENSBURG    381 (FAIR)
GOLDENDALE    181 (POOR)
TRI-CITIES    122 (POOR)
WALLA WALLA   270 (POOR)
YAKIMA         65 (POOR)
BEND          117 (POOR)
PRINEVILLE     99 (POOR)
ENTERPRISE    128 (POOR)
HERMISTON     260 (POOR)
JOHN DAY      150 (POOR)
LA GRANDE     211 (POOR)
MADRAS        128 (POOR)
MEACHAM       138 (POOR)
PENDLETON     287 (POOR)
REDMOND       112 (POOR)
SENECA        121 (POOR)
THE DALLES    330 (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.
$$