textproduct: Pendleton

KEY MESSAGES

- Breezy winds return to portions of the area today. *Wind Advisory Active*

- Elevated fire weather concerns persist. *Fire Weather Watches in Effect*

- Warming and drying trend through the week, peaking midweek.

DISCUSSION

Current radar and visible satellite imagery shows dry conditions under mostly clear skies. There is some smoke present across areas of central and eastern Oregon that are near the Grasshopper, Hagen, and Rowe Creek Complex incidents. These conditions are in response to an upper level trough and accompanying mid-level jet that will keep breezy conditions across the Kittitas Valley, Eastern Columbia Gorge, and east slopes of the Cascades. Winds are expected to peak between 3 PM and 7 PM with sustained west-northwest winds of 25-35 mph with gusts of 40-50 mph, which have warranted the issuance of a Wind Advisory across the Kittitas Valley until 10 PM this evening. The NBM advertises a 60-80% chance of sustained winds of 30 mph or greater and also of gusts reaching 45 mph or greater.

A thermal trough develops along the coast as upper level support in the form of a ridge stalls just offshore. These features will allow for surface high pressure to develop across the area as a surface low encroaches north along the Oregon/Washington coasts to promote north-northeast winds across the area. This wind direction will also usher in a dry, continental airmass resulting in moderate to poor overnight humidity recoveries Tuesday and Wednesday morning as afternoon humidities drop into the single digits to mid-teens. Sustained east-northeast winds of 15-25 mph with gusts to around 30 mph are expected during this timeframe. These values will be focused across the Lower Columbia Basin of Oregon, Eastern Columbia Gorge, and the Warm Springs areas, which has warranted the issuance of a Fire Weather Watch over these zones (OR691, OR701, and OR702) for Tuesday.

The thermal trough and east-northeast winds will also allow for a significant warming trend to commence through much of the week. Heat is expected to peak Thursday and Friday as the upper level ridge axis slides over the area. High temperatures both days will reach between 95-105 across the Lower Columbia Basin, Central Oregon, Blue Mountain foothills, Eastern Columbia Gorge, and the Yakima/Kittitas Valleys. Currently, the NBM indicates a 40-60% chance of highs reaching triple digits across the Tri- Cities, Yakima, and Walla Walla areas Thursday, dropping to a 20-40% chance on Friday. Widespread Moderate (2 of 4) and isolated Major (3 of 4) HeatRisk is present Thursday, with scattered Moderate HeatRisk lingering on Friday for the aforementioned areas. 75

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

VFR conditions expected through the TAF period. Gusty winds at DLS through 10Z with wind gusts 15 to 20 kts. All other sites will have winds 10 kts or less. CIGs are mostly SKC and no VSBY concerns are expected.

FIRE WEATHER

Elevated fire weather concerns persist today across Central Oregon zones before becoming more focused across the Lower Columbia Basin and Eastern Columbia Gorge areas Monday through Wednesday associated with east-northeast winds resulting from a developing thermal trough along the coast. Elevated 700mb winds, upper level support, and terrain induced enhancement coupled with east-northeast wind directions will bring in a very dry airmass. A Fire Weather Watch has been issued for OR691, OR701, and OR702 Tuesday.

Elevated concerns linger through the week and approach critical conditions Friday and Saturday associated with a dropping upper level shortwave that suppresses the ridge responsible for heat and east-northeast winds. At this time, the main concerns reside across WA690, OR691, OR701, OR702, and OR703 both days.

Moderate to poor overnight humidity recoveries are also anticipated Wednesday through Friday mornings with humidities of 20-40% across much of the region. 75

Preliminary Point Temps/PoPs

PDT 77 45 81 48 / 0 0 0 0 ALW 78 50 83 54 / 0 0 0 0 PSC 83 50 86 52 / 0 0 0 0 YKM 80 50 84 56 / 0 0 0 0 HRI 81 50 85 53 / 0 0 0 0 ELN 71 49 81 54 / 0 0 0 0 RDM 76 37 82 44 / 0 0 0 0 LGD 76 44 82 48 / 0 0 0 0 GCD 80 43 84 48 / 0 0 0 0 DLS 78 55 86 59 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...Air Quality Alert until 2 PM PDT Monday for WAZ028>030. OR...Fire Weather Watch from Tuesday morning through Tuesday evening for ORZ691-701>703. Air Quality Alert until 2 PM PDT Monday for ORZ044-049-050-502- 503-505>511.