


Daily Dispersion Outlook
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
097 AUUS46 KPDT 041225 DDOPDT DAILY DISPERSION OUTLOOK NATIONAL WEATHER SERVICE PENDLETON OR 525 AM PDT SAT OCT 4 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 5-13 MPH. W 8-10 MPH. TRANSPORT WINDS SW 8-14 MPH. W 9-12 MPH. MIXING HEIGHT NEAR SURFACE. 7500 FT MSL. DISPERSION CATEGORY POOR. FAIR. OUTLOOK FOR SUN OCT 5 FAIR. OUTLOOK FOR MON OCT 6 FAIR. VENTILATION INDEX (CATEGORY) 84 (POOR). 510 (FAIR). OUTLOOK FOR SUN OCT 5 215 (POOR). OUTLOOK FOR MON OCT 6 150 (POOR). FOR THE UPPER YAKIMA VALLEY INCLUDING YAKIMA...UNION GAP... SELAH...AND NACHES AREA 7:00 AM AFTERNOON SURFACE WINDS W 4-8 MPH. NW 7-10 MPH. TRANSPORT WINDS NW 6-11 MPH. NW 9-13 MPH. MIXING HEIGHT NEAR SURFACE. 8000 FT MSL. DISPERSION CATEGORY POOR. FAIR. OUTLOOK FOR SUN OCT 5 FAIR. OUTLOOK FOR MON OCT 6 FAIR. VENTILATION INDEX (CATEGORY) 81 (POOR). 564 (FAIR). OUTLOOK FOR SUN OCT 5 629 (GOOD). OUTLOOK FOR MON OCT 6 172 (POOR). FOR THE GRANDE RONDE RIVER VALLEY 7:00 AM AFTERNOON SURFACE WINDS N 4-9 MPH. NW 11-16 MPH. TRANSPORT WINDS W 5-9 MPH. NW 12-15 MPH. MIXING HEIGHT 4000 FT MSL. 8000 FT MSL. DISPERSION CATEGORY POOR. FAIR. OUTLOOK FOR SUN OCT 5 GOOD. OUTLOOK FOR MON OCT 6 POOR. VENTILATION INDEX (CATEGORY) 129 (POOR). 608 (GOOD). OUTLOOK FOR SUN OCT 5 548 (FAIR). OUTLOOK FOR MON OCT 6 159 (POOR). FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS 7:00 AM AFTERNOON SURFACE WINDS SW 6-13 MPH. W 8-12 MPH. TRANSPORT WINDS SW 9-15 MPH. W 11-14 MPH. MIXING HEIGHT NEAR SURFACE. 6000 FT MSL. DISPERSION CATEGORY FAIR. FAIR. OUTLOOK FOR SUN OCT 5 FAIR. OUTLOOK FOR MON OCT 6 FAIR. VENTILATION INDEX (CATEGORY) 121 (POOR). 529 (FAIR). OUTLOOK FOR SUN OCT 5 157 (POOR). OUTLOOK FOR MON OCT 6 176 (POOR). SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES CLE ELUM 664 (GOOD) ELLENSBURG 752 (GOOD) GOLDENDALE 556 (FAIR) TRI-CITIES 461 (FAIR) WALLA WALLA 490 (FAIR) YAKIMA 770 (GOOD) BEND 365 (FAIR) PRINEVILLE 315 (FAIR) ENTERPRISE 664 (GOOD) HERMISTON 493 (FAIR) JOHN DAY 530 (FAIR) LA GRANDE 693 (GOOD) MADRAS 474 (FAIR) MEACHAM 440 (FAIR) PENDLETON 628 (GOOD) REDMOND 346 (FAIR) SENECA 583 (FAIR) THE DALLES 798 (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. $$