textproduct: Pendleton

KEY MESSAGES

- Precipitation chances move through Washington state and, to a lesser extent, parts of northern Oregon through tomorrow.

- Dry and warmer conditions prevail Wednesday through Friday east of the Cascades.

- Active weather resumes (90% confidence) Friday and into the weekend with widespread showers and high mountain snow.

DISCUSSION

Satellite displays low to mid level clouds through the region, with SCT to BKN decks at less than 900 feet across valleys and sheltered areas. Radar shows a few light returns across the Basin, but has dried out significantly compared to earlier tonight. Patchy fog similarly has been observed near the Yakima Valley and parts of the Columbia Gorge across interstates 82 and 84. On and off fog will continue through these areas and other parts in the Basin through the night. Always pay attention for the potential for sudden visibility changes while on roads through the overnight and early morning hours.

Synoptic wise, the shortwave that brought rain across the area has mostly pushed out into Idaho, bringing drier conditions across the area. By Tuesday, a weak warm front that's embedded with a shortwave will pass through the area, with precip chances mainly secluded to Washington state and parts of northern Oregon. Higher precip chances (50-70%) will mainly be in areas east of the Cascades in Washing state, while parts of northern Oregon see PoP's at around 20-30%. Great confidence (>90% chance) the souther part of the CWA remains dry through at least Tuesday. Most of the measurable precip will be in the eastern slopes of the Cascade crests in Washington state (50-70% confidence) with NBM advertising QPFS less than a tenth of an inch through Wednesday morning (70-80% chance).

Much of the area remains dry through at least Thursday with ensemble guidance indicating a ridge amplifying in the 500 mb level over the plains and west coast. This results in warmer temperatures through mid-week with high temperatures climbing into the mid to upper 60s in most of the lower elevation areas (80-90% confidence).

Ensemble guidance into the weekend sets-up a scene in the mid- level pattern for active weather to develop (>90% confidence) another system pushing through. Clusters remain fairly uncertain going into Friday & the weekend with a cut-off low/shortwave developing off the coast. High PoP's return as well as breezy wind to locally windy conditions (40-70% confidence) across the area. By Sunday, 44% of members develops a ridge just to the east over the Great Plains with a stronger trough set-up to the west, allowing for more widespread precipitation across the area. Will need to see if snow advisories are needed through the weekend, but chances remain low (>40%) as NBM advertises snow levels above 5500 feet for most of the time frame.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

VFR conditions expected to prevail throughout most of the area with DLS/YKM being noteworthy exceptions. IFR ceilings currently present at DLS is expected to continue off and on through around 16z as scattered showers move through the area. Likewise, while skies are currently clear at YKM, guidance is suggesting that borderline IFR ceilings (3000-3500 ft) may be present alongside showers from 18-23z (around 25-35% chance). Otherwise, visibilities are expected to stay at VFR and winds are expected to remain around 5-10 kts.

Preliminary Point Temps/PoPs

PDT 67 43 66 39 / 10 10 0 0 ALW 64 48 66 46 / 30 10 0 0 PSC 61 37 59 35 / 30 20 0 0 YKM 57 38 59 37 / 50 30 0 0 HRI 62 39 60 36 / 10 10 0 0 ELN 50 35 56 35 / 80 30 0 0 RDM 65 38 69 37 / 0 0 0 0 LGD 59 43 63 43 / 10 10 0 0 GCD 64 38 69 36 / 0 0 0 0 DLS 61 44 61 42 / 30 10 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...None. OR...None.