865
AUUS46 KPDT 211225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT THU AUG 21 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.          N 7-10 MPH.
TRANSPORT WINDS               SW 4-8 MPH.         N 7-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI AUG 22        FAIR.
OUTLOOK FOR SAT AUG 23        FAIR.

VENTILATION INDEX (CATEGORY)  42 (POOR).          267 (POOR).
OUTLOOK FOR FRI AUG 22        221 (POOR).
OUTLOOK FOR SAT AUG 23        215 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 2-5 MPH.         E 3-7 MPH.
TRANSPORT WINDS               NW 5-9 MPH.         E 3-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI AUG 22        FAIR.
OUTLOOK FOR SAT AUG 23        FAIR.

VENTILATION INDEX (CATEGORY)  57 (POOR).          202 (POOR).
OUTLOOK FOR FRI AUG 22        381 (FAIR).
OUTLOOK FOR SAT AUG 23        368 (FAIR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 2-5 MPH.         N 6-8 MPH.
TRANSPORT WINDS               N 5-6 MPH.          N 6-8 MPH.
MIXING HEIGHT                 4000 FT MSL.        10000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR FRI AUG 22        GOOD.
OUTLOOK FOR SAT AUG 23        GOOD.

VENTILATION INDEX (CATEGORY)  76 (POOR).          325 (FAIR).
OUTLOOK FOR FRI AUG 22        226 (POOR).
OUTLOOK FOR SAT AUG 23        136 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 3-8 MPH.          N 7-9 MPH.
TRANSPORT WINDS               S 5-9 MPH.          N 7-9 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI AUG 22        FAIR.
OUTLOOK FOR SAT AUG 23        FAIR.

VENTILATION INDEX (CATEGORY)  46 (POOR).          285 (POOR).
OUTLOOK FOR FRI AUG 22        226 (POOR).
OUTLOOK FOR SAT AUG 23        201 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      298 (POOR)
ELLENSBURG    278 (POOR)
GOLDENDALE    291 (POOR)
TRI-CITIES    244 (POOR)
WALLA WALLA   248 (POOR)
YAKIMA        202 (POOR)
BEND          321 (FAIR)
PRINEVILLE    197 (POOR)
ENTERPRISE    251 (POOR)
HERMISTON     198 (POOR)
JOHN DAY      385 (FAIR)
LA GRANDE     338 (FAIR)
MADRAS        300 (POOR)
MEACHAM       238 (POOR)
PENDLETON     304 (FAIR)
REDMOND       107 (POOR)
SENECA        407 (FAIR)
THE DALLES    229 (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.
$$