040
AUUS46 KPDT 201225
DDOPDT
DAILY DISPERSION OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
525 AM PDT WED MAY 20 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 5-11 MPH. NW 5-9 MPH.
TRANSPORT WINDS SW 6-11 MPH. NW 6-8 MPH.
MIXING HEIGHT NEAR SURFACE. 8000 FT MSL.
DISPERSION CATEGORY POOR. FAIR.
OUTLOOK FOR THU MAY 21 FAIR.
OUTLOOK FOR FRI MAY 22 FAIR.
VENTILATION INDEX (CATEGORY) 110 (POOR). 398 (FAIR).
OUTLOOK FOR THU MAY 21 512 (FAIR).
OUTLOOK FOR FRI MAY 22 379 (FAIR).
FOR THE UPPER YAKIMA VALLEY INCLUDING YAKIMA...UNION GAP...
SELAH...AND NACHES AREA
7:00 AM AFTERNOON
SURFACE WINDS W 2-6 MPH. W 4-5 MPH.
TRANSPORT WINDS NW 4-7 MPH. N 5-6 MPH.
MIXING HEIGHT NEAR SURFACE. 8000 FT MSL.
DISPERSION CATEGORY POOR. POOR.
OUTLOOK FOR THU MAY 21 FAIR.
OUTLOOK FOR FRI MAY 22 FAIR.
VENTILATION INDEX (CATEGORY) 84 (POOR). 335 (FAIR).
OUTLOOK FOR THU MAY 21 399 (FAIR).
OUTLOOK FOR FRI MAY 22 365 (FAIR).
FOR THE GRANDE RONDE RIVER VALLEY
7:00 AM AFTERNOON
SURFACE WINDS W 0-2 MPH. NW 9-13 MPH.
TRANSPORT WINDS W 3-7 MPH. NW 10-14 MPH.
MIXING HEIGHT NEAR SURFACE. 9000 FT MSL.
DISPERSION CATEGORY POOR. GOOD.
OUTLOOK FOR THU MAY 21 GOOD.
OUTLOOK FOR FRI MAY 22 GOOD.
VENTILATION INDEX (CATEGORY) 60 (POOR). 466 (FAIR).
OUTLOOK FOR THU MAY 21 648 (GOOD).
OUTLOOK FOR FRI MAY 22 274 (POOR).
FOR THE BASE OF THE NORTHERN BLUE MOUNTAINS
7:00 AM AFTERNOON
SURFACE WINDS S 3-10 MPH. NW 6-9 MPH.
TRANSPORT WINDS SW 6-11 MPH. NW 7-10 MPH.
MIXING HEIGHT NEAR SURFACE. 6500 FT MSL.
DISPERSION CATEGORY POOR. FAIR.
OUTLOOK FOR THU MAY 21 FAIR.
OUTLOOK FOR FRI MAY 22 FAIR.
VENTILATION INDEX (CATEGORY) 99 (POOR). 377 (FAIR).
OUTLOOK FOR THU MAY 21 417 (FAIR).
OUTLOOK FOR FRI MAY 22 335 (FAIR).
SELECT AFTERNOON FORECAST VENTILATION INDICES FOR SOME CITIES
CLE ELUM 402 (FAIR)
ELLENSBURG 364 (FAIR)
GOLDENDALE 347 (FAIR)
TRI-CITIES 367 (FAIR)
WALLA WALLA 288 (POOR)
YAKIMA 332 (FAIR)
BEND 416 (FAIR)
PRINEVILLE 461 (FAIR)
ENTERPRISE 424 (FAIR)
HERMISTON 341 (FAIR)
JOHN DAY 471 (FAIR)
LA GRANDE 481 (FAIR)
MADRAS 363 (FAIR)
MEACHAM 340 (FAIR)
PENDLETON 373 (FAIR)
REDMOND 475 (FAIR)
SENECA 573 (FAIR)
THE DALLES 324 (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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