190
AUUS46 KPDT 161225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT THU OCT 16 2025

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 2-8 MPH.         SW 5-9 MPH.
TRANSPORT WINDS               S 5-9 MPH.          SW 8-11 MPH.
MIXING HEIGHT                 NEAR SURFACE.       3500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI OCT 17        GOOD.
OUTLOOK FOR SAT OCT 18        POOR.

VENTILATION INDEX (CATEGORY)  37 (POOR).          194 (POOR).
OUTLOOK FOR FRI OCT 17        524 (FAIR).
OUTLOOK FOR SAT OCT 18        84 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 1-4 MPH.         SE 3-7 MPH.
TRANSPORT WINDS               NW 2-5 MPH.         S 4-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       3000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI OCT 17        FAIR.
OUTLOOK FOR SAT OCT 18        POOR.

VENTILATION INDEX (CATEGORY)  27 (POOR).          75 (POOR).
OUTLOOK FOR FRI OCT 17        290 (POOR).
OUTLOOK FOR SAT OCT 18        123 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 N 2-5 MPH.          NW 3-7 MPH.
TRANSPORT WINDS               NW 4-8 MPH.         NW 6-10 MPH.
MIXING HEIGHT                 4000 FT MSL.        7000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI OCT 17        GOOD.
OUTLOOK FOR SAT OCT 18        FAIR.

VENTILATION INDEX (CATEGORY)  67 (POOR).          246 (POOR).
OUTLOOK FOR FRI OCT 17        551 (FAIR).
OUTLOOK FOR SAT OCT 18        324 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 4-8 MPH.          SW 4-9 MPH.
TRANSPORT WINDS               S 7-10 MPH.         SW 6-11 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI OCT 17        GOOD.
OUTLOOK FOR SAT OCT 18        FAIR.

VENTILATION INDEX (CATEGORY)  54 (POOR).          192 (POOR).
OUTLOOK FOR FRI OCT 17        731 (GOOD).
OUTLOOK FOR SAT OCT 18        157 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      417 (FAIR)
ELLENSBURG    308 (FAIR)
GOLDENDALE    221 (POOR)
TRI-CITIES    174 (POOR)
WALLA WALLA   242 (POOR)
YAKIMA         76 (POOR)
BEND          161 (POOR)
PRINEVILLE    136 (POOR)
ENTERPRISE    198 (POOR)
HERMISTON     164 (POOR)
JOHN DAY      240 (POOR)
LA GRANDE     274 (POOR)
MADRAS        106 (POOR)
MEACHAM       125 (POOR)
PENDLETON     209 (POOR)
REDMOND       116 (POOR)
SENECA        327 (FAIR)
THE DALLES    370 (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.
$$