160
AUUS46 KPDT 121225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT SUN OCT 12 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 15-29 MPH.       SW 12-16 MPH.
TRANSPORT WINDS               SW 19-32 MPH.       SW 19-22 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4000 FT MSL.
DISPERSION CATEGORY           GOOD.               GOOD.
OUTLOOK FOR MON OCT 13        GOOD.
OUTLOOK FOR TUE OCT 14        POOR.

VENTILATION INDEX (CATEGORY)  274 (POOR).         701 (GOOD).
OUTLOOK FOR MON OCT 13        423 (FAIR).
OUTLOOK FOR TUE OCT 14        159 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 5-13 MPH.         SW 7-12 MPH.
TRANSPORT WINDS               W 8-16 MPH.         SW 11-18 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           FAIR.               FAIR.
OUTLOOK FOR MON OCT 13        GOOD.
OUTLOOK FOR TUE OCT 14        FAIR.

VENTILATION INDEX (CATEGORY)  148 (POOR).         616 (GOOD).
OUTLOOK FOR MON OCT 13        667 (GOOD).
OUTLOOK FOR TUE OCT 14        368 (FAIR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 8-14 MPH.         S 7-9 MPH.
TRANSPORT WINDS               W 13-19 MPH.        SW 14-16 MPH.
MIXING HEIGHT                 5000 FT MSL.        6000 FT MSL.
DISPERSION CATEGORY           GOOD.               FAIR.
OUTLOOK FOR MON OCT 13        FAIR.
OUTLOOK FOR TUE OCT 14        FAIR.

VENTILATION INDEX (CATEGORY)  354 (FAIR).         448 (FAIR).
OUTLOOK FOR MON OCT 13        162 (POOR).
OUTLOOK FOR TUE OCT 14        167 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SW 15-25 MPH.       SW 10-17 MPH.
TRANSPORT WINDS               SW 22-27 MPH.       SW 18-22 MPH.
MIXING HEIGHT                 2000 FT MSL.        4000 FT MSL.
DISPERSION CATEGORY           GOOD.               GOOD.
OUTLOOK FOR MON OCT 13        FAIR.
OUTLOOK FOR TUE OCT 14        POOR.

VENTILATION INDEX (CATEGORY)  344 (FAIR).         604 (GOOD).
OUTLOOK FOR MON OCT 13        251 (POOR).
OUTLOOK FOR TUE OCT 14        119 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      703 (GOOD)
ELLENSBURG    511 (FAIR)
GOLDENDALE    571 (FAIR)
TRI-CITIES    830 (GOOD)
WALLA WALLA   598 (FAIR)
YAKIMA        447 (FAIR)
BEND          547 (FAIR)
PRINEVILLE    584 (FAIR)
ENTERPRISE    469 (FAIR)
HERMISTON     662 (GOOD)
JOHN DAY      565 (FAIR)
LA GRANDE     531 (FAIR)
MADRAS        727 (GOOD)
MEACHAM       322 (FAIR)
PENDLETON     780 (GOOD)
REDMOND       490 (FAIR)
SENECA        524 (FAIR)
THE DALLES    534 (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.
$$