422
AUUS46 KPDT 191225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT SAT SEP 19 2026

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 2-8 MPH.          NW 2-5 MPH.
TRANSPORT WINDS               S 5-10 MPH.         NW 2-5 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SUN SEP 20        POOR.
OUTLOOK FOR MON SEP 21        FAIR.

VENTILATION INDEX (CATEGORY)  41 (POOR).          95 (POOR).
OUTLOOK FOR SUN SEP 20        124 (POOR).
OUTLOOK FOR MON SEP 21        136 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 0-3 MPH.         SE 3-7 MPH.
TRANSPORT WINDS               NW 3-7 MPH.         SE 4-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SUN SEP 20        POOR.
OUTLOOK FOR MON SEP 21        POOR.

VENTILATION INDEX (CATEGORY)  25 (POOR).          138 (POOR).
OUTLOOK FOR SUN SEP 20        165 (POOR).
OUTLOOK FOR MON SEP 21        120 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 N 1-4 MPH.          N 4-9 MPH.
TRANSPORT WINDS               NW 3-6 MPH.         N 8-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SUN SEP 20        FAIR.
OUTLOOK FOR MON SEP 21        GOOD.

VENTILATION INDEX (CATEGORY)  28 (POOR).          330 (FAIR).
OUTLOOK FOR SUN SEP 20        210 (POOR).
OUTLOOK FOR MON SEP 21        282 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 3-7 MPH.          NW 2-5 MPH.
TRANSPORT WINDS               S 5-9 MPH.          N 4-5 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SUN SEP 20        FAIR.
OUTLOOK FOR MON SEP 21        FAIR.

VENTILATION INDEX (CATEGORY)  42 (POOR).          116 (POOR).
OUTLOOK FOR SUN SEP 20        162 (POOR).
OUTLOOK FOR MON SEP 21        178 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      119 (POOR)
ELLENSBURG    129 (POOR)
GOLDENDALE    121 (POOR)
TRI-CITIES     93 (POOR)
WALLA WALLA    78 (POOR)
YAKIMA        128 (POOR)
BEND          167 (POOR)
PRINEVILLE    128 (POOR)
ENTERPRISE    300 (POOR)
HERMISTON      91 (POOR)
JOHN DAY      208 (POOR)
LA GRANDE     331 (FAIR)
MADRAS        122 (POOR)
MEACHAM       158 (POOR)
PENDLETON     115 (POOR)
REDMOND       172 (POOR)
SENECA        301 (FAIR)
THE DALLES     54 (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.
$$