textproduct: Pendleton

KEY MESSAGES

- Hot and dry conditions persist as a ridge pushes into the area. Breezy diurnal winds develop, with gusts up to 20-30 mph possible.

- Widespread moderate HeatRisk development expected through the early week, with chances of major HeatRisk developing as well.

- Slight chance (10-30%) of isolated to scattered thunderstorms possible across Central Oregon through the Southern Blue Mountains in the mid-week thanks to oncoming monsoonal moisture.

DISCUSSION

Satellite and radar advertise the expected dry weather pattern thanks to the ridge situated over the lower 48. The upper level ridge coupled with smoke from local and surrounding wildfires will continue to degrade air quality over the next few days. The DEQ of Oregon has issued an Air Quality Advisory that is currently in effect through at least Monday afternoon.

Models are in good agreement that the shortwave situated over British Colombia will continue to push off into the northeast with the ridge situated over the lower 48 to move over the four corners. This set-up will allow monsoonal moisture to transport over the PacNW and saturate the mid-levels. With CAPE values advertised to reach as high as 350 J/kg over Central Oregon through the Southern Blues, chances of isolated to scattered dry thunderstorms to develop increase to 10-30% through Wednesday. Plenty of time to monitor, but guidance is suggesting these will be mostly dry in nature with low PWAT values as of now.

Heat wise, NBM is showing high chances of the populated areas of the Columbia Basin reaching triple digits at 50-70% on Tuesday and Wednesday. Chances slightly decrease to 30-50% heading into Thursday. HeatRisk chances advertise widespread >90% of moderate HeatRisk developing by Tuesday, lasting through Thursday (although chances decrease to 60-80% by Thursday). Chances of major HeatRisk are populated at 30-50% for the populated areas of the Columbia Basin, increasing to 40-70% chances going into Wednesday. Will monitor for potential heat highlights but as of now it looks like Tuesday/Wednesday will be the hottest days as of now with major HeatRisk not out of the question as of now.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

VFR conditions prevail with winds generally light in nature at less than 15 knots through the forecast period. No CIG issues expected since conditions will clear to partly cloudy, but smoke still lingers around the TAF sites due to local wildfires in the area. There is a small chance (5-15%) for each TAF site that smoke could drop visibility's VV to MVFR or below.

Preliminary Point Temps/PoPs

PDT 91 61 91 64 / 0 0 0 0 ALW 93 65 94 68 / 0 0 0 0 PSC 93 62 94 66 / 0 0 0 0 YKM 93 63 94 68 / 0 0 0 0 HRI 93 63 93 66 / 0 0 0 0 ELN 90 59 92 66 / 0 0 0 0 RDM 93 60 89 60 / 0 0 10 0 LGD 95 60 93 64 / 0 0 0 0 GCD 96 61 94 61 / 0 0 0 0 DLS 95 65 95 70 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...None. OR...Air Quality Alert until noon PDT Monday for ORZ050-502-503-505- 506-508.