Marine Weather Net

Cape Shoalwater WA to Cascade Head OR out 10 NM Marine Forecast


REST OF TODAY

SW
WINDS
5 KNOTS

TONIGHT

W
WINDS
TO 5
KNOTS

WED

N
WINDS
5 - 10
KNOTS

WED NIGHT

N
WINDS
5 - 10
KNOTS

The Marine Weather Forecast In Detail:
PZZ250 Forecast Issued: 847 AM PDT Tue Sep 13 2022

DENSE FOG ADVISORY IN EFFECT UNTIL 10 PM PDT THIS EVENING
Rest Of Today...Sw Wind 5 Kt. Wind Waves Sw 1 Ft At 4 Seconds. Nw Swell 2 Ft At 9 Seconds. Widespread Dense Fog In The Morning. Areas Of Dense Fog In The Afternoon.
Tonight...Nw Wind To 5 Kt. Wind Waves Nw 1 Ft At 4 Seconds. Nw Swell 2 Ft At 9 Seconds. Areas Of Dense Fog In The Evening. Patchy Dense Fog After Midnight.
Wed...N Wind 5 To 10 Kt. Wind Waves N 1 Ft At 4 Seconds. Nw Swell 2 Ft At 9 Seconds.
Wed Night...N Wind 5 To 10 Kt. Wind Waves N 2 Ft At 4 Seconds. Nw Swell 3 Ft At 9 Seconds.
Thu...Ne Wind To 5 Kt, Backing To Nw In The Afternoon. Wind Waves Ne 1 Ft At 4 Seconds, Shifting To The Nw At 4 Seconds In The Afternoon. Nw Swell 3 Ft At 10 Seconds.
Thu Night...Nw Wind 5 Kt. Wind Waves N 1 Ft At 4 Seconds. Nw Swell 3 Ft At 10 Seconds.
Fri...Nw Wind 5 To 10 Kt. Wind Waves 2 Ft. Nw Swell 4 Ft.
Sat...Nw Wind 5 To 10 Kt. Wind Waves 2 Ft. Nw Swell 4 Ft.
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Area Forecast Discussion
National Weather Service Portland OR
238pm PDT Sat July 13 2024

Synopsis
Above normal temperatures will persist for inland portions of SW Washington and NW Oregon through next weekend, though onshore flow should help to guard against more extreme temperatures. Flow aloft will turn more southerly Tuesday, potentially carrying moisture and instability northward from California. This will lead to about a 10-15% chance of thunderstorms Tuesday afternoon into Tuesday night, with the best chance being over the Cascades Tuesday afternoon and evening.

.SHORT TERM...Now through Monday Night...Another blue sky day across northwest Oregon and southwest Washington as visible satellite shows shallow marine stratus eroding away from all but the immediate coastline as of early Saturday afternoon. The upper level pattern remains characterized by strong high pressure over the Four Corners region and a cutoff low near the central California coast, with fairly benign westerly flow across the Pacific Northwest. In terms of sensible weather impacts, this will maintain the status quo through Monday as onshore flow and the marine layer moderate the coastal areas but remain too shallow to provide much relief east of the Coast Range. With that in mind, the interior valleys will continue to see highs generally around or slightly above 90 degrees each day through Monday. The pattern begins to subtly shift by Monday night as the low off the California coast starts to move closer to the area and introduces potential additional forecast concerns heading into the middle of next week. More on that below. /CB

Long Term
Tuesday through Saturday...Next week will feature a more amplified upper level pattern as high pressure continues to build over the western CONUS into Canada and a large scale trough deepens over the northeast Pacific. The will turn flow more southerly across the Pacific Northwest between the two features, introducing several forecast concerns as we move towards the middle of next week. First, next Tuesday and Wednesday look to be the hottest days of the upcoming week as the ridge amplifies to the east, resulting in 500 mb height rises and sending 850 mb temps into the 20-22 C range. Guidance depicts a 60-80 percent chance to exceed 95 degrees across the Willamette Valley on Tuesday, with a 40-50 percent chance on Wednesday. The probability to reach 100 degrees each of these days has also notably ticked upward to around 25 percent with this morning's guidance. Coupled with overnight lows creeping back into the mid to upper 60s, this is enough to push the HeatRisk back into the major category for the Portland metro on Tuesday. There are still some caveats which could ultimately lower the temperature forecast, as southerly flow could advect more high cloud cover in ahead of the low off the California coast, or even potential smoke from the wildfires occurring across parts of CA. Another consideration will be the potential for southerly flow to advect more moisture into the area, which could lead to more muggy conditions by Pacific Northwest standards even if temperatures stay in the low 90s. Regardless, people should be prepared for slightly enhanced heat concerns Tuesday into Wednesday.

The other item that will bear watching heading into next week is the aforementioned low off of California as it is drawn northward towards the area in southerly flow next Tuesday. This type of setup is often associated with increased thunderstorm activity as mid level moisture is advected into region. Ensemble based probabilistic guidance often struggles a few days out in these scenarios and remains subdued (around 5 percent) on thunderstorm potential at this time, but opted to introduce a slight (15 percent) chance of thunderstorms for Tuesday across parts of the Oregon Cascades based on pattern recognition and agreement from deterministic guidance across several model suites. Bottom line, given the ongoing stretch of hot and dry weather, those with fire weather interests should keep an eye on the forecast and any potential for lightning next Tuesday and Wednesday.

Beyond Wednesday, hot and dry weather continues as we head into the end of next week, with temperature guidance generally settling back into the low 90s as upper level flow pivots more southwesterly and maintains some semblance of onshore flow. /CB

Marine
High pressure will maintain northerly winds across the waters for much of the next week. Winds will generally be strongest off the central coast of Oregon and lightest off the mouth of the Columbia River each day. Winds will typically peak each day in the late afternoon and evening hours, with gusts at times just barely meeting Small Craft Advisory criteria at 20-25 kt.

Probabilities of 20 kt winds or greater do decrease substantially (to less than 20%) across the waters off even the central coast of Oregon towards next Tuesday and Wednesday. In the meantime, seas will primarily be a hybrid of fresh swell/wind-driven waves through the weekend. Current SCA (Small Craft Advisory) conditions will end late Saturday night, with gusts up to 20-25 kt returning Sunday evening. /Neuman/JLiu

NOAA Portland OR Office: Watches - Warnings - Advisories
OR...None. WA...None. PZ...Small Craft Advisory until 5pm PDT this afternoon for PZZ252- 253.

Small Craft Advisory until 5am PDT Sunday for PZZ271>273.