FXUS66 KPDT 051707 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 1007 AM PDT Wed Aug 5 2026 .KEY MESSAGES... - Elevated to locally critical fire weather conditions will continue to persist through at least the better part of this week. - Widespread moderate risk of heat expected to develop through the region by Thursday. - Smoke and haze from local and regional wildland fires continue to suppress air quality levels through at least Thursday. && .DISCUSSION... Satellite & other night time products continue to show widespread smoke and haze across the region from local and regional wildland fires ignited over the past few weeks. Smoke is expected to linger through at least Thursday (>90% chance) as a ridge located offshore continues to move towards the region through Thursday. This has allowed unhealthy levels of air quality to accumulate, thus local agencies from Oregon & Washington have issued Air Quality Alerts/Advisories for the entire forecast area. With the ridge axis expected to reach over the area in the Thursday/Friday timeframe, we expect a warming trend to continue until then with the NBM advertising chances of reaching triple digits in parts of the Columbia Basin at around 30-50%. Guidance is in very good agreement with HeatRisk values reaching 'moderate' with widespread chances of 80-100%. Isolated areas of major HeatRisk is possible with 30-50% chances possible Thursday & Friday in parts of the Yakima/Kittitas region. With that being said, wildland fire smoke could inhibit the ridge bringing its full potential of heat. Areas with thicker columns of smoke may fall short several degrees than otherwise expected, possibly tapering levels below major that would've reached it otherwise. This brings issuing heat advisories at a low confidence (10-30%) due too the difficult to forecast smoke plumes in the area. Guidance in the synoptic level through the weekend is in good agreement that the pattern will turn into a zonal/quasi-zonal flow with tighter pressure gradients, resulting in breezy to locally windy conditions developing late this week. With dry air lingering with minimum relative humidities still in the 10-18 percent range Friday and Saturday, chances of critical weather conditions developing go up with 20-30% confidence. The main factor in increased confidence will be how far and widespread the winds will be. Although local areas are expected to be critical, it's not anticipated it will be a widespread event, thus no fire weather highlights will be issued for the weekend at this time. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Widespread smoke and haze from local and regional wildland fires continue to impact all TAF sites through the next 24-hours. Smoke is dense enough that many sites are seeing MVFR and IFR conditions. This will continue through the period. Winds are to light to clear the smoke from the area. && .Preliminary Point Temps/PoPs... PDT 90 54 97 61 / 0 0 0 0 ALW 93 60 98 67 / 0 0 0 0 PSC 92 58 98 60 / 0 0 0 0 YKM 90 56 98 62 / 0 0 0 0 HRI 93 56 98 64 / 0 0 0 0 ELN 88 55 95 63 / 0 0 0 0 RDM 92 53 98 54 / 0 0 0 0 LGD 94 54 99 61 / 0 0 0 0 GCD 97 56 100 59 / 0 0 0 0 DLS 97 57 99 64 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...Air Quality Alert until 5 AM PDT Tuesday for WAZ024-026>030- 521>523. OR...Air Quality Alert until 5 AM PDT Tuesday for ORZ041-044-049- 050-502-503-505>511. && $$ DISCUSSION...95 AVIATION...90