Marine Weather and Tide Forecast for Portland, OR

DISCUSSION
Quiet weather prevails across the region this morning as a weak upper level ridge shifts inland from the Pacific, with mostly cloudy skies in place west of the Cascade crest. Onshore flow will maintain seasonably mild weather today as the ridge is gradually flattened out by a subtle disturbance currently noted crossing 140W on water vapor imagery. Expect partly to mostly cloudy skies to persist today ahead of this feature, with afternoon highs topping out in the low to mid 60s inland and the 50s along the coast. The weak shortwave will cross the region tonight into early Tuesday accompanied by a surface front that will bring light rain to much of the area.
Model QPF amounts continue to look rather minimal with this system, with the highest amounts confined to northern coastal areas where the NBM depicts a 30-40% chance for as much as a quarter inch of rain from roughly Tillamook up through the Long Beach Peninsula. Elsewhere, amounts will generally range from a tenth or two in the Cowlitz Valley in Washington to a few hundredths of an inch in the south Willamette Valley through late Tuesday morning. SHowers will taper off across most area by Tuesday afternoon but could linger a bit longer over the Cascades, with afternoon highs very similar to today. Onshore flow will also maintain gusty west winds of 20-30 mph through the western Columbia River Gorge over the next few days.

Warmer and dryer weather returns to the region on Wednesday as a ridge of high pressure builds overhead and sends temperatures back into the 70s in the interior lowlands. Latest guidance continues to suggest Thursday will be the hottest day of the week, with the NBM still indicating an 80-90% probability to reach 80 degrees in the Portland Metro and a 40-60% chance across the rest of the interior valley locations. Coastal locations will notably remain cooler as marine layer influences hold temperatures in those locations down in the 60s. The period of warm weather will be relatively short lived as WPC ensemble clusters continue to show good agreement in the ridge shifting east by Friday and opening the door for the next upper level trough approaching the region. This will bring another round of cooler and wetter weather to the area from Friday into next weekend. /CB

AVIATION
A mix of high end MVFR and low end VFR conditions with BKN/OVC cloud deck around 2.5-4 kft. Winds will remain mostly light and variable - mostly northwesterly in the afternoon. Conditions along the coast will also maintain a mix of MVFR and VFR conditions becoming all VFR in the afternoon. Westerly flow less than 10 kt expected. A weak disturbance approaching the area tonight wills support light rain and MVFR CIGs to all terminals late tonight into Tuesday morning.

PDX AND APPROACHES...VFR conditions persist through the TAF period. Light winds generally northwesterly through the period.
Chance for light rain and MVFR conditions late tonight into Tuesday morning. -Batz

MARINE
High pressure over the northeast Pacific continues to shift inland, supporting benign conditions into next week.
Expect seas around 5 to 7 feet and mostly northwesterly winds at or below 10 kt with gusts 15 kt or less.

A short Small Craft Advisory for the Columbia River Bar has been issued for steep ebb chop and will come to end by 8 AM Monday.
Ebb current of 7.35 kt and seas 7 to 8 feet expected. Another steep ebb chop with a current of 7.36 kt and seas around 9 feet is expected around 6 AM Tuesday. -Hall/Batz

PQR WATCHES/WARNINGS/ADVISORIES

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