Marine Weather and Tide Forecast for Tokeland, WA

DISCUSSION
Sunday through Saturday...Satellite imagery and observations show marine stratus over the waters and along the coast early Sunday morning as high pressure has formed just off the coast. Patchy drizzle is possible through this morning along the coast and over the waters under this pattern. The marine stratus is expected to make a push inland over the next few hours as the high pressure moves east over the coast, bringing stratus and potentially fog into the Willamette Valley. Model soundings and HRRR guidance indicate the best chances will be south of Washington County (60-70% chance of stratus and 30-50% chance of fog), though there's a 30% chance some low clouds will make it up to the Portland/Vancouver metro area for a few hours this morning. These clouds are expected to dissipate by late morning, and as the high pressure continues moving inland along with clear skies this afternoon, inland high temperatures are forecast to be similar to yesterday with mid to upper 70s for inland valleys.

Ensemble guidance continues to show multiple frontal systems are expected to move through the PacNW associated with a longwave trough and surface low pressure system originating in the Gulf of Alaska as it moves east into Canada through Thursday. The first of these is a weak front that begins approaching the coast tonight into Monday morning. As clouds stream inland ahead of the frontal passage tomorrow, daytime temperatures will be anywhere from 3-5 degrees cooler in the southern counties of the CWA to 5-10 degrees cooler in the northern counties than Sunday's temperatures. Light rain is slated to begin moving into the southern WA and far northern OR coast by mid morning and slowly moving southeast to reach the valley by the evening hours. Latest guidance continues diminishing precipitation amounts as the front moves inland with only a few hundredths of an inch expected inland, 0.1-0.25 inch along the coast north of Newport, and less than 0.1 inch along the coast south of Newport.

The next frontal system is slated to move through the PacNW Tuesday into Wednesday, and ensemble guidance indicates this will bring more widespread rain than the area has seen recently. Some uncertainty still remains in the specific amounts, but both the GFS and Euro ensembles indicate IVT values of around or over 250 kg/ms, which means this frontal system is tapping into a bit of tropical moisture. Another front is expected to push in quickly Wednesday night into Thursday morning, bringing another round of widespread precipitation through the region. The 01z Sunday NBM run indicates a 45-70% chance of at least 1 inch of rain for inland valleys and a 75-90% chance for the coast and higher elevations from 5 AM Tuesday through 5 AM Thursday. For at least 2 inches of rain in the same time period, there's a 40-60% chance for the coast and higher elevations, though only a 5-20% chance for inland valleys.

Temperatures will drop significantly Tuesday into Thursday, with daytime temperatures in the mid 60s inland Tuesday and in the upper 50s by Thursday. Over the Cascades, high temperatures are expected to fall into the upper 30s by Thursday with low temperatures in the low 30s Thursday morning and upper 20s by Friday morning. These cooler temperatures will cause snow levels to drop to around 4000-4500 feet, allowing for the first Cascade snow of the season. Snow amounts over Cascade passes are not expected to be very high with NBM probabilities of 50-60% chance of 1 inch of snow and only a 20-40% chance of 4 inches of snow.
Probabilities increase a touch over 5500 feet with 60-80% chance of 1 inch and 40-70% chance of 4 inches.

Ensemble guidance hints at the potential for another frontal system over the PacNW Saturday with 70% of the WPC clusters indicating rain continuing into next weekend. Uncertainty still remains in the WPC clusters and ensemble members on specific timing and amounts of precipitation next week, so keep an eye out on future updates. -HEC

AVIATION
Satellite imagery and surface observations as of 10z Sun depicts light offshore flow dissipating parts of the marine layer. As a result, vis and cigs have been bouncing between IFR, MVFR, and VFR at the coast. Guidance does depict light offshore flow continuing this morning, so the marine layer may struggle to re-form. If winds become completely calm or onshore, could see cigs and/or vis fall back to IFR/LIFR thresholds along the coast.
For now, decided to keep IFR/MVFR trends in the the TAFs for coastal terminals.

Guidance still shows a 20-40% chance of IFR/MVFR cigs moving into the Willamette Valley (highest chances near KEUG) between 12-16z Sun, however, the aforementioned light offshore flow may prevent the marine layer clouds moving into the Valley. After 16z Sun, expect predominately VFR thresholds across inland terminals. The north Oregon coast (near KAST) could briefly experience VFR thresholds Sunday afternoon around 20-23z Sun. Winds will be variable and under 5 kt today.

PDX APPROACHES...25-35% chance of IFR cigs between 12-16z Sun.
Otherwise, predominately VFR thresholds through the TAF period with few/scattered high clouds and winds under 5 kt. -Alviz

MARINE
Expect benign conditions today over the waters with subsiding seas. Tonight into early Monday morning, a front will push through the waters and return breezy southerly winds 10-20 kt with gusts up to 25 kt. In addition, a large westerly swell associated with a robust low pressure system in the Gulf of Alaska will arrive and build seas to 10-12 ft at 15-17 seconds. As a result, a Small Craft Advisory was issued for all waters beginning 0500 Monday and lasting through 0800 Tuesday. As the front moves inland Monday evening, winds will weaken below 15 kt but seas will remain elevated through Tuesday morning. Expect seas to gradually fall to 8-9 feet on Tuesday.

Another front appears to push across the waters Tuesday night into Wednesday. This will bring another round of breezy southerly to southwesterly winds, however, guidance suggests a 30-50% of Small Craft Advisory level winds of 25 kt or stronger. Seas remain around 8-10 ft at 11-13 seconds through the end of the week.
-Alviz

BEACH HAZARDS
A westerly swell of 10-12 feet with a dominant period of 15-17 seconds will push towards the coast on Monday, bringing an elevated threat for sneaker waves. Therefore, a Beach Hazards Statement will go into effect Monday morning through Monday evening. Waves can run up significantly farther on a beach than normal, including over rocks and jetties. Caution should be used when in or near the water. -Alviz

PQR WATCHES/WARNINGS/ADVISORIES

OR...None.
WA...None.
PZ...Small Craft Advisory from 5 AM Monday to 8 AM PDT Tuesday for PZZ210-251>253-271>273.