988
AUUS46 KPDT 151119
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
419 AM PDT THU MAY 15 2025

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SW 10-20 MPH.       SW 11-16 MPH.
TRANSPORT WINDS               SW 13-22 MPH.       SW 13-20 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6500 FT MSL.
DISPERSION CATEGORY           FAIR.               FAIR.
OUTLOOK FOR FRI MAY 16        FAIR.
OUTLOOK FOR SAT MAY 17        FAIR.

VENTILATION INDEX (CATEGORY)  204 (POOR).         577 (FAIR).
OUTLOOK FOR FRI MAY 16        666 (GOOD).
OUTLOOK FOR SAT MAY 17        441 (FAIR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 5-9 MPH.          W 7-10 MPH.
TRANSPORT WINDS               W 5-9 MPH.          W 5-9 MPH.
MIXING HEIGHT                 NEAR SURFACE.       7500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI MAY 16        FAIR.
OUTLOOK FOR SAT MAY 17        FAIR.

VENTILATION INDEX (CATEGORY)  69 (POOR).          297 (POOR).
OUTLOOK FOR FRI MAY 16        345 (FAIR).
OUTLOOK FOR SAT MAY 17        343 (FAIR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 W 4-7 MPH.          NW 9-12 MPH.
TRANSPORT WINDS               W 5-10 MPH.         NW 10-15 MPH.
MIXING HEIGHT                 4000 FT MSL.        9000 FT MSL.
DISPERSION CATEGORY           POOR.               GOOD.
OUTLOOK FOR FRI MAY 16        FAIR.
OUTLOOK FOR SAT MAY 17        FAIR.

VENTILATION INDEX (CATEGORY)  121 (POOR).         387 (FAIR).
OUTLOOK FOR FRI MAY 16        257 (POOR).
OUTLOOK FOR SAT MAY 17        318 (FAIR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SW 12-21 MPH.       W 10-13 MPH.
TRANSPORT WINDS               SW 13-21 MPH.       SW 10-13 MPH.
MIXING HEIGHT                 NEAR SURFACE.       6500 FT MSL.
DISPERSION CATEGORY           FAIR.               FAIR.
OUTLOOK FOR FRI MAY 16        FAIR.
OUTLOOK FOR SAT MAY 17        FAIR.

VENTILATION INDEX (CATEGORY)  223 (POOR).         509 (FAIR).
OUTLOOK FOR FRI MAY 16        517 (FAIR).
OUTLOOK FOR SAT MAY 17        359 (FAIR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM      564 (FAIR)
ELLENSBURG    658 (GOOD)
GOLDENDALE    552 (FAIR)
TRI-CITIES    492 (FAIR)
WALLA WALLA   495 (FAIR)
YAKIMA        320 (FAIR)
BEND          353 (FAIR)
PRINEVILLE    434 (FAIR)
ENTERPRISE    367 (FAIR)
HERMISTON     600 (FAIR)
JOHN DAY      458 (FAIR)
LA GRANDE     462 (FAIR)
MADRAS        341 (FAIR)
MEACHAM       374 (FAIR)
PENDLETON     618 (GOOD)
REDMOND       467 (FAIR)
SENECA        559 (FAIR)
THE DALLES    777 (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.
$$