Marine Weather and Tide Forecast for Bay City, OR

DISCUSSION
Little change in the upper level pattern today as a deep low centered near Haida Gwaii maintains broad upper level troughing over the NE Pacific and robust onshore flow across the Pacific Northwest. Marine stratus has once again been stubborn to erode and has held temperatures down around 60 degrees thus far today north and west of a Portland to Tillamook line. Other parts of the area are under mostly clear skies, with temperatures climbing into the upper 60s and looking to top out in the low 70s today from Salem to Eugene as a result.
Remaining stratus is showing signs of dissipating on visible satellite as of 2 PM Saturday, which should allow highs to reach at least into the mid to upper 60s in the Portland area through early this evening.

Expect temperatures to run a little warmer across the area on Sunday in response to modest 500 mb height rises and 850 mb temps climbing to around 10-12 C. This will correspond to highs closer to the upper 70s through the interior valleys. Locations in the Willamette Valley currently show around a 25% chance to reach 80 degrees from Portland to Salem, with lower probabilities toward Eugene. Onshore flow maintains similar conditions across the area through Tuesday as highs reach the upper 70s each day in the interior valleys and stay closer to the low 60s along the coast. Models continue to keep the area dry through Monday as energy associated with an embedded shortwave trough now passes mostly south of the area into California. Light rain chances are present along the coast Monday night into Tuesday, but QPF amounts remain minimal at this time. The better chance of rain still looks to come Tuesday night into Wednesday as another shortwave and associated surface front cross the area. However, still do not expect much rainfall across the area as the probability to receive a tenth of an inch remains around 10% in the Portland area and below 5% across the rest of the Willamette Valley, with a 25-40% chance for a tenth of an inch along northern coastal areas and parts of southwest WA.

Thursday will feature a return of dry conditions with temperatures running a few degrees cooler in the low to mid 70s behind the mid week system. Not much change in thinking from Friday into next weekend as medium range ensembles continue to advertise better rain chances with the arrival of deeper upper level troughing over the Pacific Northwest. Rainfall amounts still do not look overly impressive, but the chance for a wetting rain of a quarter inch ranges from 30-40% along the coast to 20-30% over the interior valleys, with nearly all ensemble members depicting at least some measurable rain the interior valley locations from Friday into Saturday of next week. /CB



AVIATION
Largely VFR conditions expected as surface high pressure persists over the Northeast Pacific. Increasing coverage of marine stratus is expected overnight, bringing high chances (50-60%) of MVFR cigs at AST, with lower chances (20-30%) farther south toward ONP. Inland, low stratus building west from the Cascade foothills could see few-sct coverage at Willamette Valley terminals, but VFR conditions remain favored. Skies will clear across the region by 16-20Z Sun.

Diurnal north to northwest winds will continue through the period, with speeds diminishing to 5 kt or less by 08-12Z Sun, then increasing to 5-10 kt after 16-20Z Sun inland, and to 10-15 kt gusting to 20-25 kt by 18z Sun along the coast.

*KTTD ASOS is currently INOP except for altimeter and will be AMD NOT SKED.

PDX AND APPROACHES...VFR conditions expected through the period.
Few-sct stratus at 2-3 kft will build from the east, especially after 08-10z Sun and persisting into Sunday morning. Mixing increases and skies trend clearer by 18-20Z Sun. Diurnal northwest winds diminish to less than 5 kt tonight, then increase to 5-10 kt Sunday morning. -Picard

MARINE
North/northwesterly flow continues, with diurnally driven peaks in the afternoon. Winds 15-20 kt expected with gusts to around 25 kt south of Cape Falcon to Florence this afternoon and evening. A short, low end Small Craft has been issued and is in effect until 2 AM tomorrow (Sunday). Seas are generally wind driven at 3 to 5 ft. This pattern is expected to persist through the weekend.

A weak disturbance is expected to cross the region on Monday, supporting southerly winds. A westerly swell is also expected to move into the waters late Monday, generally around 5 ft at 10 seconds. Combined seas still look to remain 7 ft or less through next week. ~Hall/Batz

PQR WATCHES/WARNINGS/ADVISORIES

OR...None.
WA...None.
PZ...Small Craft Advisory until 2 AM PDT Sunday for PZZ252-253-272- 273.