


Daily Dispersion Outlook
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
394 AUUS46 KPDT 231225 DDOPDT DAILY DISPERSION OUTLOOK NATIONAL WEATHER SERVICE PENDLETON OR 525 AM PDT WED JUL 23 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 3-7 MPH. W 6-8 MPH. TRANSPORT WINDS SW 5-9 MPH. W 7-9 MPH. MIXING HEIGHT NEAR SURFACE. 10000 FT MSL. DISPERSION CATEGORY POOR. FAIR. OUTLOOK FOR THU JUL 24 GOOD. OUTLOOK FOR FRI JUL 25 GOOD. VENTILATION INDEX (CATEGORY) 79 (POOR). 512 (FAIR). OUTLOOK FOR THU JUL 24 981 (GOOD). OUTLOOK FOR FRI JUL 25 912 (GOOD). FOR THE UPPER YAKIMA VALLEY INCLUDING YAKIMA...UNION GAP... SELAH...AND NACHES AREA 7:00 AM AFTERNOON SURFACE WINDS NW 2-5 MPH. SW 4-7 MPH. TRANSPORT WINDS NW 4-7 MPH. W 6-8 MPH. MIXING HEIGHT NEAR SURFACE. 10500 FT MSL. DISPERSION CATEGORY POOR. GOOD. OUTLOOK FOR THU JUL 24 GOOD. OUTLOOK FOR FRI JUL 25 FAIR. VENTILATION INDEX (CATEGORY) 56 (POOR). 431 (FAIR). OUTLOOK FOR THU JUL 24 507 (FAIR). OUTLOOK FOR FRI JUL 25 547 (FAIR). FOR THE GRANDE RONDE RIVER VALLEY 7:00 AM AFTERNOON SURFACE WINDS SE 1-3 MPH. N 3-4 MPH. TRANSPORT WINDS N 2-4 MPH. W 6-8 MPH. MIXING HEIGHT 4000 FT MSL. 12000 FT MSL. DISPERSION CATEGORY POOR. GOOD. OUTLOOK FOR THU JUL 24 GOOD. OUTLOOK FOR FRI JUL 25 GOOD. VENTILATION INDEX (CATEGORY) 41 (POOR). 419 (FAIR). OUTLOOK FOR THU JUL 24 745 (GOOD). OUTLOOK FOR FRI JUL 25 614 (GOOD). FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS 7:00 AM AFTERNOON SURFACE WINDS S 4-8 MPH. W 6-8 MPH. TRANSPORT WINDS S 7-10 MPH. W 7-8 MPH. MIXING HEIGHT NEAR SURFACE. 9500 FT MSL. DISPERSION CATEGORY POOR. FAIR. OUTLOOK FOR THU JUL 24 GOOD. OUTLOOK FOR FRI JUL 25 GOOD. VENTILATION INDEX (CATEGORY) 95 (POOR). 537 (FAIR). OUTLOOK FOR THU JUL 24 959 (GOOD). OUTLOOK FOR FRI JUL 25 904 (GOOD). SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES CLE ELUM 768 (GOOD) ELLENSBURG 637 (GOOD) GOLDENDALE 607 (GOOD) TRI-CITIES 496 (FAIR) WALLA WALLA 539 (FAIR) YAKIMA 454 (FAIR) BEND 364 (FAIR) PRINEVILLE 485 (FAIR) ENTERPRISE 455 (FAIR) HERMISTON 493 (FAIR) JOHN DAY 726 (GOOD) LA GRANDE 474 (FAIR) MADRAS 431 (FAIR) MEACHAM 462 (FAIR) PENDLETON 514 (FAIR) REDMOND 398 (FAIR) SENECA 691 (GOOD) THE DALLES 577 (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. $$