textproduct: Pendleton

KEY MESSAGES

1. Dry and warm conditions will continue through Tuesday

2. Widespread Moderate HeatRisk through early next week

3. Pattern shift Wednesday will bring monsoonal moisture back to the region with isolated to scattered chances of thunderstorms

DISCUSSION

Current satellite shows some upper level clouds moving in over the region. It also shows plenty of smoke moving across the south eastern portion of the region from the fires in the southwestern portion of the CWA. Temperatures right now are in the 80s across much of the region and are expected to reach into the low 90s with 70s along the ridgetops.

As the ridge continues to settle in overhead, warm, dry air will continue to settle over the region. Temperatures will continue to rise with NBM showing 80-90% chances the Columbia Basin, foothills of the Blues and the Gorge will see temperatures in the 100s beginning Tuesday and persisting through Thursday. Overnight lows are expected to be in the upper 60s to low 70s with 60-80% of the NBM raw ensembles in agreement. Probabilistic HeatRisk shows a 60-70% chance of moderate HeatRisk beginning Tuesday for the aforementioned areas becoming more widespread across the CWA by Wednesday with increased probabilities to near 70-80%. With the elevated HeatRisk, heat related impacts may occur.

By Wednesday, models are in better agreement and show a slight pattern shift with the upper level ridge shifting towards the Four Corners and advecting some monsoonal moisture up into the region. Clusters show the main difference to be mainly with the amplitude of the ridge. NBM raw ensembles show Wednesday to have 10-30% chance of thunderstorms through Deschutes and Grant counties after 2 PM. Looking at soundings show CAPE values over 400 J/kg, lapse rates 8.0- 9 C/km, effective bulk shear of 25-30 kts and LIs of -4 and PWATs of 0.05-1.0 inches. NBM QPF shows these storms to be more on the drier side with less than 10% chance of a wetting rain. Will continue to monitor as the event draws closer.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

VFR conditions prevail with light winds less than 10 kts through the forecast period. Smoke still lingers around the TAF sites due to local wildfires in the area but no VIS issues expected. CIGs will remain mostly SKC with some high clouds expected later in the period.

FIRE WEATHER

Fire weather concerns will remain elevated through the week with continued hot and dry conditions. A slight shift in the pattern Wednesday will bring increased chances (10-30%) of isolated to scattered thunderstorms Wednesday afternoon to central OR and the Eastern Mountains with unstable conditions elsewhere. Fires along the outer boundaries of the thunderstorm threat will still see convective build up that could lead to outflow boundaries of 20-30 mph while fire underneath the cells could see outflows of 30-40 mph. Zones most likely affected by thunderstorms are zones OR705,700,696,697,698 and 699.

Preliminary Point Temps/PoPs

PDT 61 90 63 97 / 0 0 0 0 ALW 64 93 67 100 / 0 0 0 0 PSC 62 93 65 100 / 0 0 0 0 YKM 62 93 67 100 / 0 0 0 0 HRI 63 92 66 100 / 0 0 0 0 ELN 59 91 65 98 / 0 0 0 0 RDM 59 89 61 94 / 0 0 0 0 LGD 60 91 62 98 / 0 0 0 0 GCD 61 92 60 96 / 0 0 0 0 DLS 65 95 70 102 / 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.