519
AUUS46 KPDT 271225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT WED AUG 27 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 7-14 MPH.         SW 9-12 MPH.
TRANSPORT WINDS               SW 8-14 MPH.        N 9-12 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR THU AUG 28        FAIR.
OUTLOOK FOR FRI AUG 29        FAIR.

VENTILATION INDEX (CATEGORY)  78 (POOR).          185 (POOR).
OUTLOOK FOR THU AUG 28        310 (FAIR).
OUTLOOK FOR FRI AUG 29        292 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 4-8 MPH.          S 7-10 MPH.
TRANSPORT WINDS               NW 5-9 MPH.         E 8-11 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR THU AUG 28        POOR.
OUTLOOK FOR FRI AUG 29        POOR.

VENTILATION INDEX (CATEGORY)  51 (POOR).          363 (FAIR).
OUTLOOK FOR THU AUG 28        268 (POOR).
OUTLOOK FOR FRI AUG 29        257 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 3-6 MPH.          W 5-6 MPH.
TRANSPORT WINDS               S 5-10 MPH.         NW 7-9 MPH.
MIXING HEIGHT                 4000 FT MSL.        7000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR THU AUG 28        GOOD.
OUTLOOK FOR FRI AUG 29        GOOD.

VENTILATION INDEX (CATEGORY)  57 (POOR).          263 (POOR).
OUTLOOK FOR THU AUG 28        595 (FAIR).
OUTLOOK FOR FRI AUG 29        580 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 6-12 MPH.         SW 6-11 MPH.
TRANSPORT WINDS               S 9-12 MPH.         W 8-11 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR THU AUG 28        FAIR.
OUTLOOK FOR FRI AUG 29        FAIR.

VENTILATION INDEX (CATEGORY)  107 (POOR).         248 (POOR).
OUTLOOK FOR THU AUG 28        460 (FAIR).
OUTLOOK FOR FRI AUG 29        379 (FAIR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      299 (POOR)
ELLENSBURG    301 (FAIR)
GOLDENDALE    390 (FAIR)
TRI-CITIES    147 (POOR)
WALLA WALLA   294 (POOR)
YAKIMA        387 (FAIR)
BEND          772 (GOOD)
PRINEVILLE    692 (GOOD)
ENTERPRISE    207 (POOR)
HERMISTON     239 (POOR)
JOHN DAY      482 (FAIR)
LA GRANDE     309 (FAIR)
MADRAS        622 (GOOD)
MEACHAM       249 (POOR)
PENDLETON     221 (POOR)
REDMOND       757 (GOOD)
SENECA        565 (FAIR)
THE DALLES    565 (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.
$$