518
AUUS46 KPDT 241140
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
440 AM PDT SAT MAY 24 2025

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 2-6 MPH.          NE 3-7 MPH.
TRANSPORT WINDS               S 2-6 MPH.          NE 4-5 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SUN MAY 25        POOR.
OUTLOOK FOR MON MAY 26        GOOD.

VENTILATION INDEX (CATEGORY)  29 (POOR).          163 (POOR).
OUTLOOK FOR SUN MAY 25        142 (POOR).
OUTLOOK FOR MON MAY 26        921 (GOOD).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 2-5 MPH.         SE 4-7 MPH.
TRANSPORT WINDS               NW 2-5 MPH.         SE 5-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SUN MAY 25        FAIR.
OUTLOOK FOR MON MAY 26        GOOD.

VENTILATION INDEX (CATEGORY)  29 (POOR).          266 (POOR).
OUTLOOK FOR SUN MAY 25        194 (POOR).
OUTLOOK FOR MON MAY 26        792 (GOOD).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 N 2-4 MPH.          NE 2-4 MPH.
TRANSPORT WINDS               N 2-4 MPH.          NW 2-4 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SUN MAY 25        GOOD.
OUTLOOK FOR MON MAY 26        GOOD.

VENTILATION INDEX (CATEGORY)  31 (POOR).          94 (POOR).
OUTLOOK FOR SUN MAY 25        470 (FAIR).
OUTLOOK FOR MON MAY 26        446 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 3-6 MPH.         N 4-7 MPH.
TRANSPORT WINDS               SE 3-6 MPH.         NE 4-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR SUN MAY 25        POOR.
OUTLOOK FOR MON MAY 26        FAIR.

VENTILATION INDEX (CATEGORY)  30 (POOR).          186 (POOR).
OUTLOOK FOR SUN MAY 25        135 (POOR).
OUTLOOK FOR MON MAY 26        652 (GOOD).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      617 (GOOD)
ELLENSBURG    454 (FAIR)
GOLDENDALE    216 (POOR)
TRI-CITIES    155 (POOR)
WALLA WALLA   148 (POOR)
YAKIMA        314 (FAIR)
BEND          304 (FAIR)
PRINEVILLE    341 (FAIR)
ENTERPRISE    102 (POOR)
HERMISTON     146 (POOR)
JOHN DAY      222 (POOR)
LA GRANDE      83 (POOR)
MADRAS        169 (POOR)
MEACHAM        89 (POOR)
PENDLETON     190 (POOR)
REDMOND       269 (POOR)
SENECA        276 (POOR)
THE DALLES    208 (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.
$$