330
AUUS46 KPDT 251218
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
518 AM PDT FRI APR 25 2025

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 E 3-6 MPH.          N 7-12 MPH.
TRANSPORT WINDS               E 3-7 MPH.          NE 10-13 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT APR 26        FAIR.
OUTLOOK FOR SUN APR 27        GOOD.

VENTILATION INDEX (CATEGORY)  26 (POOR).          319 (FAIR).
OUTLOOK FOR SAT APR 26        295 (POOR).
OUTLOOK FOR SUN APR 27        573 (FAIR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 4-8 MPH.         NE 9-12 MPH.
TRANSPORT WINDS               NW 6-10 MPH.        NE 10-13 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT APR 26        FAIR.
OUTLOOK FOR SUN APR 27        GOOD.

VENTILATION INDEX (CATEGORY)  46 (POOR).          571 (FAIR).
OUTLOOK FOR SAT APR 26        494 (FAIR).
OUTLOOK FOR SUN APR 27        567 (FAIR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 E 2-3 MPH.          N 4-5 MPH.
TRANSPORT WINDS               E 4-7 MPH.          E 7-9 MPH.
MIXING HEIGHT                 NEAR SURFACE.       11000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR SAT APR 26        GOOD.
OUTLOOK FOR SUN APR 27        GOOD.

VENTILATION INDEX (CATEGORY)  40 (POOR).          376 (FAIR).
OUTLOOK FOR SAT APR 26        401 (FAIR).
OUTLOOK FOR SUN APR 27        607 (GOOD).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 4-8 MPH.         N 8-11 MPH.
TRANSPORT WINDS               SE 7-13 MPH.        NE 10-13 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR SAT APR 26        FAIR.
OUTLOOK FOR SUN APR 27        GOOD.

VENTILATION INDEX (CATEGORY)  43 (POOR).          389 (FAIR).
OUTLOOK FOR SAT APR 26        286 (POOR).
OUTLOOK FOR SUN APR 27        527 (FAIR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      598 (FAIR)
ELLENSBURG    578 (FAIR)
GOLDENDALE    618 (GOOD)
TRI-CITIES    316 (FAIR)
WALLA WALLA   264 (POOR)
YAKIMA        741 (GOOD)
BEND          415 (FAIR)
PRINEVILLE    513 (FAIR)
ENTERPRISE    502 (FAIR)
HERMISTON     341 (FAIR)
JOHN DAY     1050 (GOOD)
LA GRANDE     441 (FAIR)
MADRAS        736 (GOOD)
MEACHAM       533 (FAIR)
PENDLETON     428 (FAIR)
REDMOND       505 (FAIR)
SENECA        868 (GOOD)
THE DALLES    328 (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.
$$