974
AUUS46 KPDT 171050
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
350 AM PDT THU APR 17 2025

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 4-10 MPH.        N 12-17 MPH.
TRANSPORT WINDS               N 4-10 MPH.         N 14-19 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8500 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR FRI APR 18        FAIR.
OUTLOOK FOR SAT APR 19        GOOD.

VENTILATION INDEX (CATEGORY)  37 (POOR).          727 (GOOD).
OUTLOOK FOR FRI APR 18        257 (POOR).
OUTLOOK FOR SAT APR 19        717 (GOOD).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 5-10 MPH.        N 8-11 MPH.
TRANSPORT WINDS               N 5-10 MPH.         N 8-13 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI APR 18        FAIR.
OUTLOOK FOR SAT APR 19        GOOD.

VENTILATION INDEX (CATEGORY)  55 (POOR).          507 (FAIR).
OUTLOOK FOR FRI APR 18        206 (POOR).
OUTLOOK FOR SAT APR 19        604 (GOOD).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 11-22 MPH.       N 21-29 MPH.
TRANSPORT WINDS               NW 13-22 MPH.       N 23-31 MPH.
MIXING HEIGHT                 NEAR SURFACE.       11000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR FRI APR 18        GOOD.
OUTLOOK FOR SAT APR 19        GOOD.

VENTILATION INDEX (CATEGORY)  215 (POOR).         1050 (GOOD).
OUTLOOK FOR FRI APR 18        460 (FAIR).
OUTLOOK FOR SAT APR 19        602 (GOOD).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 4-7 MPH.          N 16-20 MPH.
TRANSPORT WINDS               NW 4-7 MPH.         N 17-22 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR FRI APR 18        FAIR.
OUTLOOK FOR SAT APR 19        GOOD.

VENTILATION INDEX (CATEGORY)  46 (POOR).          871 (GOOD).
OUTLOOK FOR FRI APR 18        340 (FAIR).
OUTLOOK FOR SAT APR 19        783 (GOOD).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      404 (FAIR)
ELLENSBURG    425 (FAIR)
GOLDENDALE    482 (FAIR)
TRI-CITIES    623 (GOOD)
WALLA WALLA   843 (GOOD)
YAKIMA        458 (FAIR)
BEND          595 (FAIR)
PRINEVILLE    792 (GOOD)
ENTERPRISE   1050 (GOOD)
HERMISTON     644 (GOOD)
JOHN DAY     1050 (GOOD)
LA GRANDE    1050 (GOOD)
MADRAS        718 (GOOD)
MEACHAM       789 (GOOD)
PENDLETON     836 (GOOD)
REDMOND       746 (GOOD)
SENECA       1050 (GOOD)
THE DALLES    320 (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.
$$