Marine Weather and Tide Forecast for Corvallis, OR

DISCUSSION
Now through Thursday...Overall pretty near average temperatures for late July are anticipated over the coming week. The coast and more northern locations will be in the running for a couple rounds of light rain or drizzle.

A weak front will push into the region Saturday as a weak low pressure moves northeastward towards western Washington. This will bring with it light rain chances to mainly the coast and Coast Range Saturday and increasing southerly winds across the region. NBM 12-hour probabilities for measureable precipitation are generally around 20-30% north of Waldport along the immediate coast, but rise into the 50-60% range across the west facing slopes of the Coast Range and Willapa Hills. The odds that any location receives more than a tenth of an inch is generally below 10% except across the terrain of Tillamook, Clatsop and Pacific Counties. It will be unusually breezy with southerly wind gusts increasing into the 25-35 mph range along the coast.

Looking beyond the weekend, more seasonable temperatures hang on into early next week before uncertainty increases during the middle of the week. Cluster analysis favors the ridge slowly building back into the PacNW which in turn would bring an increase in afternoon high temperatures. The NBM 10th-90th percentile reveals there's an 80% chance each day that temperatures end up somewhere between the upper 70s and upper 80s through the end of next week. A weak front pushing towards and possibly into the region does appear most likely to result in a slight dip in temperatures Tuesday into Wednesday along with bringing another round of light rain to the north coast although there is a notable signal in some of the global ensemble guidance that even locations along the I5 corridor and certainly in the Cascades north of Portland/Vancouver will experience at least some light measurable rain on Tuesday.




AVIATION
Through 06z Sunday...Satellite imagery and surface observations show mainly VFR conditions across the Willamette Valley. A mix of MVFR and IFR conditions exist along the coast as marine clouds congeal. Models are in good agreement IFR and MVFR ceilings will by and large persist through 00-06z Sunday along the coast. In fact, this pattern is conducive for KONP to gradually drop down into LIFR conditions as we move towards the 00-06z Sunday time period. There is a 30-40% chance for MVFR ceilings at any given hour for inland terminals between 12-18z Saturday as a modest southwesterly oriented marine push brings at least some marine clouds through the Coast Range gaps overnight spreading into the Willamette Valley. Marine stratus coverage and timing of arrival for inland terminals remains somewhat uncertain, but clouds are actively pushing into the Coast Range gaps so confidence is increasing that some MVFR ceilings will impact some, if not all, terminals by 12-15z Saturday. What MVFR conditions come to fruition should generally improve to VFR between 18-21z Saturday with VFR conditions expected thereafter. Expect a period of southerly wind gusts of 25-30 kt along the coast Saturday and 15-20 kt for inland terminals.

KPDX AND APPROACHES...Predominately VFR through the TAF period with a 30-40% chance for MVFR CIGs at any given hour between 12-18z Saturday. Winds should turn southerly overnight with gusts of 15-20 kt Saturday afternoon as a weak front slides into the region.




MARINE
Weak low pressure offshore continues to support light south to southeasterly winds and seas of 3-5 ft. As the aforementioned low pressure shifts northeastward towards the Washington coast Saturday, a front will move eastward across the waters and result in southerly wind gusts increasing into the 23-28 kt range across the waters. In what would be pretty exceptional for late July, there is a 10-20% chance southerly winds at least briefly climb into the 30-35 kt range within 20NM of the coast. Again, this does not appear likely, but it's not out of the question either. Current Small Craft Advisories cover the wind hazard well at this point.

Either way, larger and steeper wind driven seas will result with seas climbing into at least the 5-7 ft range with dominant periods shortening into the 4-8 second range Saturday. There is a >80% chance that the front will push ashore by 8 PM Saturday, which will result in winds and seas subsiding across the waters during the evening and overnight hours on Saturday.

Another weak front will approach the waters late Sunday into early Monday with just a 25% chance that the far outer waters beyond 40 NM north of Cape Falcon will see southerly wind gusts at least briefly rise into the 22-25 kt range. Another front will push towards the waters late Monday into Tuesday. While this front stands a better chance (~50-60%) of bringing southerly 22-25 kt wind gusts to all of the waters north of Cape Falcon, the probability those winds extend as far south as Cape Foulweather is just 10-20%.

Winds appear likely to return to a more typical Summertime northerly wind pattern during the latter half of next week. Once we get past Saturday, seas will generally be in the 3-5 ft range for much of the next week unless some of the stronger wind scenarios mentioned above come to fruition.




PQR WATCHES/WARNINGS/ADVISORIES
OR...None.
WA...None.
PZ...Small Craft Advisory from 11 AM to 8 PM PDT Saturday for PZZ210.
Small Craft Advisory from 6 AM to 8 PM PDT Saturday for PZZ251>253-271>273.