477
AUUS46 KPDT 301225
DDOPDT
DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT THU APR 30 2026
*** AIR DISPERSION CATEGORIES: GOOD, FAIR, POOR ***
FOR THE COLUMBIA BASIN FROM PENDLETON TO WALLA WALLA AND PASCO
7:00 AM AFTERNOON
SURFACE WINDS E 2-5 MPH. NE 6-10 MPH.
TRANSPORT WINDS E 3-6 MPH. E 7-10 MPH.
MIXING HEIGHT NEAR SURFACE. 7500 FT MSL.
DISPERSION CATEGORY POOR. FAIR.
OUTLOOK FOR FRI MAY 1 FAIR.
OUTLOOK FOR SAT MAY 2 FAIR.
VENTILATION INDEX (CATEGORY) 31 (POOR). 360 (FAIR).
OUTLOOK FOR FRI MAY 1 188 (POOR).
OUTLOOK FOR SAT MAY 2 191 (POOR).
FOR THE UPPER YAKIMA VALLEY INCLUDING YAKIMA...UNION GAP...
SELAH...AND NACHES AREA
7:00 AM AFTERNOON
SURFACE WINDS NW 2-5 MPH. E 5-7 MPH.
TRANSPORT WINDS NW 3-6 MPH. E 7-9 MPH.
MIXING HEIGHT NEAR SURFACE. 8500 FT MSL.
DISPERSION CATEGORY POOR. FAIR.
OUTLOOK FOR FRI MAY 1 FAIR.
OUTLOOK FOR SAT MAY 2 GOOD.
VENTILATION INDEX (CATEGORY) 46 (POOR). 534 (FAIR).
OUTLOOK FOR FRI MAY 1 265 (POOR).
OUTLOOK FOR SAT MAY 2 591 (FAIR).
FOR THE GRANDE RONDE RIVER VALLEY
7:00 AM AFTERNOON
SURFACE WINDS N 2-4 MPH. N 3-5 MPH.
TRANSPORT WINDS NE 3-7 MPH. E 4-5 MPH.
MIXING HEIGHT 4000 FT MSL. 10000 FT MSL.
DISPERSION CATEGORY POOR. FAIR.
OUTLOOK FOR FRI MAY 1 GOOD.
OUTLOOK FOR SAT MAY 2 GOOD.
VENTILATION INDEX (CATEGORY) 59 (POOR). 236 (POOR).
OUTLOOK FOR FRI MAY 1 697 (GOOD).
OUTLOOK FOR SAT MAY 2 640 (GOOD).
FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS
7:00 AM AFTERNOON
SURFACE WINDS SE 3-6 MPH. N 6-10 MPH.
TRANSPORT WINDS SE 6-11 MPH. NE 7-10 MPH.
MIXING HEIGHT NEAR SURFACE. 6500 FT MSL.
DISPERSION CATEGORY POOR. FAIR.
OUTLOOK FOR FRI MAY 1 FAIR.
OUTLOOK FOR SAT MAY 2 FAIR.
VENTILATION INDEX (CATEGORY) 71 (POOR). 349 (FAIR).
OUTLOOK FOR FRI MAY 1 355 (FAIR).
OUTLOOK FOR SAT MAY 2 188 (POOR).
SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM 751 (GOOD)
ELLENSBURG 620 (GOOD)
GOLDENDALE 642 (GOOD)
TRI-CITIES 374 (FAIR)
WALLA WALLA 246 (POOR)
YAKIMA 579 (FAIR)
BEND 396 (FAIR)
PRINEVILLE 289 (POOR)
ENTERPRISE 295 (POOR)
HERMISTON 317 (FAIR)
JOHN DAY 381 (FAIR)
LA GRANDE 308 (FAIR)
MADRAS 325 (FAIR)
MEACHAM 313 (FAIR)
PENDLETON 355 (FAIR)
REDMOND 358 (FAIR)
SENECA 329 (FAIR)
THE DALLES 533 (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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