640
AUUS46 KPDT 171225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT THU JUL 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                 S 6-13 MPH.         W 10-14 MPH.
TRANSPORT WINDS               SW 7-13 MPH.        W 10-16 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8500 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR FRI JUL 18        GOOD.
OUTLOOK FOR SAT JUL 19        GOOD.

VENTILATION INDEX (CATEGORY)  131 (POOR).         734 (GOOD).
OUTLOOK FOR FRI JUL 18        884 (GOOD).
OUTLOOK FOR SAT JUL 19        972 (GOOD).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 3-6 MPH.         NW 6-9 MPH.
TRANSPORT WINDS               NW 5-9 MPH.         W 6-8 MPH.
MIXING HEIGHT                 NEAR SURFACE.       9500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI JUL 18        GOOD.
OUTLOOK FOR SAT JUL 19        GOOD.

VENTILATION INDEX (CATEGORY)  100 (POOR).         420 (FAIR).
OUTLOOK FOR FRI JUL 18        536 (FAIR).
OUTLOOK FOR SAT JUL 19        653 (GOOD).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SE 2-3 MPH.         NW 10-12 MPH.
TRANSPORT WINDS               SW 3-6 MPH.         W 13-15 MPH.
MIXING HEIGHT                 4000 FT MSL.        11000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR FRI JUL 18        GOOD.
OUTLOOK FOR SAT JUL 19        GOOD.

VENTILATION INDEX (CATEGORY)  112 (POOR).         837 (GOOD).
OUTLOOK FOR FRI JUL 18        823 (GOOD).
OUTLOOK FOR SAT JUL 19        1049 (GOOD).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 6-12 MPH.         W 10-14 MPH.
TRANSPORT WINDS               S 10-13 MPH.        W 14-16 MPH.
MIXING HEIGHT                 NEAR SURFACE.       8000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR FRI JUL 18        GOOD.
OUTLOOK FOR SAT JUL 19        GOOD.

VENTILATION INDEX (CATEGORY)  195 (POOR).         816 (GOOD).
OUTLOOK FOR FRI JUL 18        909 (GOOD).
OUTLOOK FOR SAT JUL 19        1049 (GOOD).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      616 (GOOD)
ELLENSBURG    642 (GOOD)
GOLDENDALE    706 (GOOD)
TRI-CITIES    449 (FAIR)
WALLA WALLA   780 (GOOD)
YAKIMA        379 (FAIR)
BEND          947 (GOOD)
PRINEVILLE    836 (GOOD)
ENTERPRISE    965 (GOOD)
HERMISTON     806 (GOOD)
JOHN DAY     1050 (GOOD)
LA GRANDE     915 (GOOD)
MADRAS        699 (GOOD)
MEACHAM       596 (FAIR)
PENDLETON     930 (GOOD)
REDMOND       829 (GOOD)
SENECA       1050 (GOOD)
THE DALLES    725 (GOOD)

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.
$$