591
AUUS46 KPDT 291225
DDOPDT
DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT WED APR 29 2026
*** AIR DISPERSION CATEGORIES: GOOD, FAIR, POOR ***
FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO
7:00 AM AFTERNOON
SURFACE WINDS S 3-7 MPH. N 6-11 MPH.
TRANSPORT WINDS SW 5-9 MPH. NE 7-10 MPH.
MIXING HEIGHT NEAR SURFACE. 6500 FT MSL.
DISPERSION CATEGORY POOR. FAIR.
OUTLOOK FOR THU APR 30 FAIR.
OUTLOOK FOR FRI MAY 1 POOR.
VENTILATION INDEX (CATEGORY) 66 (POOR). 309 (FAIR).
OUTLOOK FOR THU APR 30 290 (POOR).
OUTLOOK FOR FRI MAY 1 165 (POOR).
FOR THE UPPER YAKIMA VALLEY INCLUDING YAKIMA...UNION GAP...
SELAH...AND NACHES AREA
7:00 AM AFTERNOON
SURFACE WINDS W 2-5 MPH. E 5-7 MPH.
TRANSPORT WINDS NW 4-8 MPH. E 7-8 MPH.
MIXING HEIGHT NEAR SURFACE. 8000 FT MSL.
DISPERSION CATEGORY POOR. FAIR.
OUTLOOK FOR THU APR 30 POOR.
OUTLOOK FOR FRI MAY 1 FAIR.
VENTILATION INDEX (CATEGORY) 63 (POOR). 416 (FAIR).
OUTLOOK FOR THU APR 30 344 (FAIR).
OUTLOOK FOR FRI MAY 1 284 (POOR).
FOR THE GRANDE RONDE RIVER VALLEY
7:00 AM AFTERNOON
SURFACE WINDS NW 1-3 MPH. N 8-11 MPH.
TRANSPORT WINDS N 3-5 MPH. NE 8-11 MPH.
MIXING HEIGHT 4000 FT MSL. 10000 FT MSL.
DISPERSION CATEGORY POOR. GOOD.
OUTLOOK FOR THU APR 30 GOOD.
OUTLOOK FOR FRI MAY 1 GOOD.
VENTILATION INDEX (CATEGORY) 80 (POOR). 446 (FAIR).
OUTLOOK FOR THU APR 30 303 (FAIR).
OUTLOOK FOR FRI MAY 1 438 (FAIR).
FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS
7:00 AM AFTERNOON
SURFACE WINDS S 2-6 MPH. N 8-11 MPH.
TRANSPORT WINDS SW 5-9 MPH. NE 8-11 MPH.
MIXING HEIGHT NEAR SURFACE. 5500 FT MSL.
DISPERSION CATEGORY POOR. FAIR.
OUTLOOK FOR THU APR 30 FAIR.
OUTLOOK FOR FRI MAY 1 FAIR.
VENTILATION INDEX (CATEGORY) 59 (POOR). 305 (FAIR).
OUTLOOK FOR THU APR 30 334 (FAIR).
OUTLOOK FOR FRI MAY 1 236 (POOR).
SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM 522 (FAIR)
ELLENSBURG 478 (FAIR)
GOLDENDALE 436 (FAIR)
TRI-CITIES 286 (POOR)
WALLA WALLA 232 (POOR)
YAKIMA 461 (FAIR)
BEND 302 (FAIR)
PRINEVILLE 375 (FAIR)
ENTERPRISE 415 (FAIR)
HERMISTON 276 (POOR)
JOHN DAY 376 (FAIR)
LA GRANDE 400 (FAIR)
MADRAS 372 (FAIR)
MEACHAM 275 (POOR)
PENDLETON 326 (FAIR)
REDMOND 376 (FAIR)
SENECA 292 (POOR)
THE DALLES 372 (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.
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