SHORT TERM
Now through Tuesday night...Radar, satellite, and surface observations as of 230 PM PDT depict dry weather across the region with broken cloud cover as an elongated upper trough moves southward toward California. There remains a 25-50% chance of showers in the Linn and Lane County Cascades through the early evening, but the vast majority of places will stay dry through tonight. The upper trough will eventually become a cut- off low tonight and spin over California/Nevada. Flow aloft will turn more northeasterly and lead to some light offshore flow in the high Cascades overnight. Everywhere else, winds will be light and variable with mostly clear skies for most places.
Tonight's lows are forecast in the upper 40s to low 50s, except upper 30s to 40s in the Cascades.

Monday will be the sunniest and warmest day of the week as high pressure aloft briefly returns over the region. Conditions will be dry with afternoon highs forecast in the mid to upper 70s for interior lowlands and mid to upper 60s along the coast.
Still can't rule out temps reaching 80 for the Willamette Valley as NBM suggests a 15-30% chance of high temps of 80 degrees or warmer from Eugene to Portland. Overall, Monday will be a great day for outdoor activities before the next frontal system arrives and brings more unsettled weather.

Monday night into Tuesday, a frontal system will arrive and bring widespread rain. In terms of timing, the front begins to approach northwest Oregon and southwest Washington after 11 PM Monday. At this point, winds will begin to shift more southerly and be breezy at times. Precipitation chances reach the coast after 5 AM Tuesday and spread inland through the morning. Based on high resolution models, rain will reach the Willamette Valley, Portland/Vancouver Metro, and Cowlitz Valley by late morning Tuesday. 24 hour rain totals ending 5 AM Wednesday are forecast around 0.35-0.70 inch for interior lowland valleys, except less than 0.25 inch closer to the central Columbia River Gorge and Upper Hood River Valley. Along the coast, Coast Range, and Cascades, 24 hour rain totals are forecast around 0.50-0.80 inch, with locally higher amounts up to 1 inch on the west slopes of the Coast Range.

Probabilities for 24 hour rain amounts over 1 inch ending 5 AM Wednesday are around 10-25% for lowlands between Kelso and Corvallis. Probabilities increase to around 30-50% along the I-5 corridor from Junction City to Cottage Grove. 40-60% chance along the coast and Coast Range, and a 30-50% chance in the Cascades. Regardless of exact rain amounts, enough will fall to result in a significant damper on fire activity. Temps will also fall 10-15 degrees below normal on Tuesday, with highs struggling to rise above the low 60s for lowland areas and 50s in the Cascades. -Alviz

LONG TERM
Wednesday through Saturday...Ensemble guidance suggests that the upper level trough associated with Tuesday's rain will exit southward toward California on Wednesday. Expect some post-frontal showers Wednesday morning, but shower chances will quickly diminish by the afternoon as weak high pressure re-builds. Model soundings also suggest decreasing clouds on Wednesday, so temps will rebound to the upper 60s and low 70s.
Expect similar temps Thursday through Saturday. Most ensemble guidance depicts shortwave ridging late in the week (Thursday to Friday), resulting in dry conditions. However, there is a bit more uncertainty on Saturday as about 55% of ensemble members from WPC cluster analysis depicts troughing returning to the region. If this occurs, cooler and wetter weather would return this weekend. For now, the current forecast includes NBM's 20-40% chance of PoPs going into Saturday. -Alviz

AVIATION
Satellite shows scattered cumulus over the region which is due to the post frontal environment. Most showers have dissipated at this point leaving behind VFR CIGs and VIS. Winds are northerly which is causing gusts to increase along north-south aligned terrain like the Willamette Valley and along the coast.
These winds are expected to persist until after sunset when they will once again become light. While skies will be patchy overnight, temperatures do not lower enough for fog to be a concern. The coast is one of the locations that would be most prone, but the active winds will help keep those areas fog-free.
Hi-resolution guidance is suggesting some lower end stratus forming around KONP - around a 40% chance for IFR CIGs . Due to low confidence have omitted from TAFs.

High pressure builds on Monday keeping conditions VFR with no concerns. Along the coastal terminals winds will be gusty at times with winds up to 20 kt - especially through early Monday morning until 17Z.

PDX APPROACHES...General VFR through the next 24 hours with a few periods of MVFR CIGs with passing clouds. Will see steady improvement through the day. Winds may become breezy in the afternoon, but gusts not expected to exceed 20 kt. -Muessle

MARINE
High pressure over the outer waters will build tonight into Sunday. As such, will maintain the northerly pressure gradients, with gusty north winds Sunday night. Small Craft Advisory continues for late this afternoon into Monday, where have gusts 20 to 25 kt. Have extended this advisory into the northern outer waters (PZZ271) for the same time period as seas will increase and, when combined with the winds sitting on the marginal side of thresholds, would prompt this advisory. Will note that conditions have been slow to respond today so it is possible that it will take a bit longer for buoys to show these conditions.
However, nearshore observations inland are showing gusts up to 20 kt. Will continue to monitor at this point. Overall, seas stay in 5 to 8 ft through Monday, with highest seas well offshore.

On Tuesday we will see yet another pattern shift as a strengthening low pressure system drops down from British Columbia. By time it reaches the waters, it will elongate/weaken.
Winds not really turning to southerly (as do with most fronts), but may briefly get burst of west to southwest winds of 20 to 25 kt with the frontal passage. Models still vary some on the timing/strength of this system, so will see how things shape up as get closer in time to Tuesday. -Muessle/MH

PQR WATCHES/WARNINGS/ADVISORIES

OR...None.
WA...None.
PZ...Small Craft Advisory until 11 AM PDT Monday for PZZ252-253.

Small Craft Advisory until 11 PM PDT Monday for PZZ271>273.