Marine Weather and Tide Forecast for Minnehaha, WA

DISCUSSION
Now through Saturday night...A compact upper-level shortwave trough is current dropping southward through Washington and Oregon this afternoon leading to an brief increase in pop-up shower activity as seen on radar and satellite. Expect these showers to quickly decrease after sunset with dry weather returning this evening. Going forward a ridge to high pressure over the eastern Pacific will meander over the Pacific Northwest by Monday and Tuesday, bringing dry weather with return of offshore flow and mostly clear skies after some morning fog and/or low stratus. This pattern is expected to last through at least Wednesday evening/night. The aforementioned clearing during the overnight hours will lead to efficient radiational cooling, supporting much colder overnight temperatures and widespread frost development especially where lighter winds are present. Low temps each night early this week are forecast in the upper 20s to mid 30s for locations west of the Cascades.
NBM probabilities for falling below 32 degrees in the Willamette Valley and other inland valleys are generally 40-80% each night with the highest probabilities for more rural outlying areas. Expect mostly sunny afternoons with highs in the 40s to low 50s.

Early Thursday to Friday, precipitation chances return as models hint at a weak decaying frontal boundary riding over-top the ridge and grazing the the region to the north. Based on the latest WPC ensemble clustering, around 30-50% of ensemble members show measurable precipitation returning to region, primarily in the mountains, although in virtually all scenarios precipitation is rather light. If you're in the Willamette Valley or along the central Oregon Coast there's a decent chance you just end up dry through this period. Deterministic and ensemble guidance are in good agreement on the return of dry and cooler conditions late weekend with some models hinting at a much colder airmass dropping down from Canada east of the Cascades - we'll need to watch this closely. The latest NWS Climate Prediction Center (CPC) 6-10 day outlook ending Jan 22 shows a 60-80% chance for below normal temperatures across the Pacific Northwest.
-Schuldt/Alviz

AVIATION
A mixture of all flight conditions continues with upper level clouds slowly scour out. However, low level IFR/LIFR cigs have become well established within the Willamette Valley.
Expect these lowered flight conditions to persist and spread further within the Willamette Valley through 03Z Monday. Models are suggesting that clouds will scour out as a quick passing low, around 06Z Monday will bring cold and clear conditions to the airspace. Cold (near freezing) overnight temperatures, there is the probability of areas seeing frost rather than fog.

PDX AND APPROACHES...Variable conditions expected to persist with a 50-60% probability for IFR/LIFR conditions manifesting around 00Z Monday. Around 06Z Monday skies are expected to clear resulting in cold, near freezing overnight temperatures could result in frost rather than fog development after 06Z Monday. /42

MARINE
A persistent, long period, northwesterly swell will keep seas near 10 ft though Monday morning, along with northerly winds with gusts up to 25 kt. Therefore, have issued a Small Craft Advisory through at least Monday morning.

A strong ebb cycle may also lead to locally hazardous conditions for those attempting to cross the Columbia River Bar today and tomorrow afternoon.

Otherwise, relatively benign conditions expected across the waters starting late Monday and persisting through the middle of the week as high pressure becomes more established over the region. Seas remain dominated by a mid to long period westerly swell, but seas are expected to remain around 7 to 10 ft through at least the middle of the week. /42

BEACH HAZARDS
A longer period swell entering the coastal waters this evening at around 10 ft at 18 seconds will lead to an enhanced risk of sneaker waves on area beaches through Monday afternoon. Beachgoers should be mindful of conditions in the surf zone and keep their eyes on the ocean as waves may run up farther onto the beach than anticipated at times.

PQR WATCHES/WARNINGS/ADVISORIES

OR...None.
WA...None.
PZ...Small Craft Advisory until 10 AM PST Monday for PZZ210-251>253- 271>273.