073
AUUS46 KPDT 171225
DDOPDT

DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT THU SEP 17 2026

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

FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO

                              7:00 AM             AFTERNOON
SURFACE WINDS                 SW 0-5 MPH.         SW 3-6 MPH.
TRANSPORT WINDS               W 4-9 MPH.          W 5-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       3500 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI SEP 18        FAIR.
OUTLOOK FOR SAT SEP 19        POOR.

VENTILATION INDEX (CATEGORY)  33 (POOR).          105 (POOR).
OUTLOOK FOR FRI SEP 18        265 (POOR).
OUTLOOK FOR SAT SEP 19        136 (POOR).

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

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 0-5 MPH.         W 2-5 MPH.
TRANSPORT WINDS               NW 6-11 MPH.        N 5-9 MPH.
MIXING HEIGHT                 NEAR SURFACE.       4500 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI SEP 18        POOR.
OUTLOOK FOR SAT SEP 19        POOR.

VENTILATION INDEX (CATEGORY)  43 (POOR).          220 (POOR).
OUTLOOK FOR FRI SEP 18        150 (POOR).
OUTLOOK FOR SAT SEP 19        112 (POOR).

FOR THE GRANDE RONDE RIVER VALLEY

                              7:00 AM             AFTERNOON
SURFACE WINDS                 NW 2-5 MPH.         NW 3-5 MPH.
TRANSPORT WINDS               N 6-10 MPH.         N 6-10 MPH.
MIXING HEIGHT                 NEAR SURFACE.       5000 FT MSL.
DISPERSION CATEGORY           POOR.               FAIR.
OUTLOOK FOR FRI SEP 18        GOOD.
OUTLOOK FOR SAT SEP 19        FAIR.

VENTILATION INDEX (CATEGORY)  38 (POOR).          121 (POOR).
OUTLOOK FOR FRI SEP 18        257 (POOR).
OUTLOOK FOR SAT SEP 19        202 (POOR).

FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS

                              7:00 AM             AFTERNOON
SURFACE WINDS                 S 1-5 MPH.          W 3-6 MPH.
TRANSPORT WINDS               S 4-7 MPH.          W 4-7 MPH.
MIXING HEIGHT                 NEAR SURFACE.       3000 FT MSL.
DISPERSION CATEGORY           POOR.               POOR.
OUTLOOK FOR FRI SEP 18        FAIR.
OUTLOOK FOR SAT SEP 19        POOR.

VENTILATION INDEX (CATEGORY)  27 (POOR).          93 (POOR).
OUTLOOK FOR FRI SEP 18        317 (FAIR).
OUTLOOK FOR SAT SEP 19        148 (POOR).

SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM       65 (POOR)
ELLENSBURG     63 (POOR)
GOLDENDALE    157 (POOR)
TRI-CITIES    170 (POOR)
WALLA WALLA    91 (POOR)
YAKIMA        182 (POOR)
BEND          286 (POOR)
PRINEVILLE    226 (POOR)
ENTERPRISE     99 (POOR)
HERMISTON      98 (POOR)
JOHN DAY       61 (POOR)
LA GRANDE      92 (POOR)
MADRAS        174 (POOR)
MEACHAM        84 (POOR)
PENDLETON     127 (POOR)
REDMOND       235 (POOR)
SENECA        316 (FAIR)
THE DALLES     91 (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.
$$