476
AUUS46 KPDT 011225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT THU OCT  1 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 1-5 MPH.         N 4-9 MPH.
TRANSPORT WINDS               NE 2-5 MPH.         N 4-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI OCT 2         FAIR.
OUTLOOK FOR SAT OCT 3         FAIR.

VENTILATION INDEX (CATEGORY)  25 (POOR).          142 (POOR).
OUTLOOK FOR FRI OCT 2         261 (POOR).
OUTLOOK FOR SAT OCT 3         129 (POOR).

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 3-5 MPH.         SE 3-6 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI OCT 2         POOR.
OUTLOOK FOR SAT OCT 3         POOR.

VENTILATION INDEX (CATEGORY)  25 (POOR).          120 (POOR).
OUTLOOK FOR FRI OCT 2         123 (POOR).
OUTLOOK FOR SAT OCT 3         127 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NE 0-1 MPH.         N 1-3 MPH.
TRANSPORT WINDS               N 2-4 MPH.          NW 4-5 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI OCT 2         FAIR.
OUTLOOK FOR SAT OCT 3         FAIR.

VENTILATION INDEX (CATEGORY)  25 (POOR).          99 (POOR).
OUTLOOK FOR FRI OCT 2         287 (POOR).
OUTLOOK FOR SAT OCT 3         116 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 1-4 MPH.         N 3-7 MPH.
TRANSPORT WINDS               SE 3-5 MPH.         N 4-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI OCT 2         FAIR.
OUTLOOK FOR SAT OCT 3         FAIR.

VENTILATION INDEX (CATEGORY)  26 (POOR).          117 (POOR).
OUTLOOK FOR FRI OCT 2         286 (POOR).
OUTLOOK FOR SAT OCT 3         121 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      127 (POOR)
ELLENSBURG    149 (POOR)
GOLDENDALE    152 (POOR)
TRI-CITIES    115 (POOR)
WALLA WALLA    96 (POOR)
YAKIMA        134 (POOR)
BEND           99 (POOR)
PRINEVILLE     70 (POOR)
ENTERPRISE    155 (POOR)
HERMISTON     168 (POOR)
JOHN DAY      179 (POOR)
LA GRANDE     112 (POOR)
MADRAS        151 (POOR)
MEACHAM       100 (POOR)
PENDLETON     142 (POOR)
REDMOND       119 (POOR)
SENECA        252 (POOR)
THE DALLES    162 (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.
$$