Cascade Head to Florence, OR out 10 NM Marine Forecast
|Today...S Wind 20 To 25 Kt. Wind Waves S 5 Ft At 6 Seconds. W Swell 12 Ft At 14 Seconds. Rain.|
|Tonight...Sw Wind 20 To 25 Kt, Becoming Nw 15 To 20 Kt After Midnight. Gusts To 25 Kt Early In The Morning. Wind Waves Sw 5 Ft At 6 Seconds, Shifting To The Nw 4 Ft At 5 Seconds After Midnight. W Swell 10 Ft At 12 Seconds. Rain.|
|Fri...N Wind 20 To 25 Kt. Gusts To 30 Kt In The Afternoon. Wind Waves N 5 Ft At 8 Seconds. Nw Swell 10 Ft At 12 Seconds. Rain Likely.|
|Fri Night...N Wind 20 To 25 Kt. Gusts To 30 Kt In The Evening. Wind Waves N 5 Ft At 7 Seconds. Nw Swell 9 Ft At 10 Seconds.|
|Sat...Ne Wind 15 To 20 Kt With Gusts To 25 Kt, Becoming E 10 To 15 Kt With Gusts To 20 Kt In The Afternoon. Wind Waves Ne 4 Ft At 5 Seconds. Nw Swell 7 Ft At 10 Seconds.|
|Sat Night...E Wind 5 To 10 Kt, Becoming Se 10 To 15 Kt After Midnight. Wind Waves E 3 Ft At 4 Seconds. Nw Swell 5 Ft At 11 Seconds.|
|Sun...Se Wind 15 To 20 Kt. Wind Waves 4 Ft. W Swell 4 Ft.|
|Mon...S Wind 15 To 20 Kt. Wind Waves 5 Ft. W Swell 10 Ft.|
| Area Forecast Discussion|
National Weather Service Portland OR
426am PDT Thu Oct 28 2021
Light rain will continue.nue at times today, but heavier rain spreads into the area from north to south later this afternoon through tonight. Lingering showers should end Friday night and the weekend should be dry with cool offshore flow. Rain returns Monday as a front moves through with more systems spread out through the week.
.SHORT TERM...Today through Saturday...Warm frontal zone north of the area this morning, leaving the forecast area in the warm sector under light rain. The main focus of the precipitation is over the Olympic mountains in nw WA as an atmospheric river is directed in that area. Later today however the slide south into sw WA and nw OR. Models show the mean IVT 750-800 kg/ms this afternoon and evening for a location near the Columbia River entrance. Fortunately the front will be weakening and moving so any a particular location will not see prolonged period of heavy rain. Model soundings at KAST show sw wind around 40-45 kt between 1000 and 5000 ft through this evening. This will enhance orographics for the Willapa Hills and north Oregon coast range, and similarly for the south WA Cascades. Have increased Quantitative Precipitation Forecast for the Willapa Hills and north Oregon coast range and south WA Cascades for this afternoon and evening. Think there should be a few hours of 0.2" per hour over the Willapa Hills this evening. Current stage forecast for Grays River @ Rosburg bring stage up to near bankfull tonight but no flooding is expected. Will have to watch this area closely. No other hydrologic concerns with quick rises on some coastal rivers. The precipitation should quickly decrease later later tonight and Friday morning as the front continues to weaken as it moves south across the forecast area as a splitting upper trough shifts onshore.
Temperatures will be quite mild today. In fact with the southerly flow in the warm sector of this system, temperatures have been steady for rising overnight, then a cool down late tonight in the wake of the front. Snow levels will be above all but the highest peaks at around 9000 to 10000 ft, then down to 5000 to 7000 ft Friday. By that time precipitation has eased so at this time does not look like Cascades will need winter weather headlines.
The operational model runs (NAM, GFS and ECMWF) retain a portion of the upper trough near the south Oregon and north California coast late Friday and Friday night. Precipitation is expected to diminish from northwest to southeast late Friday through Friday night, but shower potential will not be completely eliminated, especially for the far south part of the forecast area where an upper lows track east near the OR/CA border. This feature may be far enough south to keep any mention of precipitation out of the forecast area Saturday morning but enough uncertainly exists to keep low chance Probability of Precipitation in the southern tier.
Saturday night through Wednesday...Expect to see chance for precipitation taper off Sat night. For Sunday daytime should be dry, but will low chances for rain at the coast in the evening per NBM which appears to be aligned with the 00Z ECMWF. GEM and GFS indicating pcpn holding off until Monday morning. Cluster Quantitative Precipitation Forecast analysis has only 1 cluster with Quantitative Precipitation Forecast above the all-member for 24hrs ending 00Z Mon. Also the all-mean Quantitative Precipitation Forecast for the same time has the 0.1" contour well offshore. So perhaps will be a dry Sunday after all. During this period will see offshore flow through the Columbia Gorge develops Saturday and then strengthens Saturday night and Sunday.
WPC 500 mb clusters valid Monday are in reasonable agreement showing the upper ridge shifting east as another weather system approaches the coast. About one-third of the GEFS and one-fourth of the EPS members are slower moving the ridge east. However, the operational ECMWF (European Centre for Medium-Range Weather Forecasts) and GFS show the leading edge of the baroclinic boundary to the coast 12Z Monday. Tuesday may end up dry, but forecast confidence is lower. /mh Weishaar
High pressure along the Oregon coast while a low pressure system heads into the WA coast near the Olympic Peninsula will keep southerly winds across the waters today, gusting up to 30 kts, with isolated 35 kt gusts. A cold front begins to push down from the WA waters late this afternoon into this evening, transitioning winds out of the north this evening and into Friday. Seas will be in the 10 to 13 foot through at least Friday afternoon. Friday, the northerly winds could be quite gusty as a strong upper level high pressure builds across the NE Pacific. At the same time a thermally induced low pressure begins to extend northward along the northern California/southern Oregon coast. This will keep seas at least 10 feet as well, continuing the Small Craft Advisory into Friday evening. By Saturday, offshore flow will be established, which may allow seas to drop below 10 ft. /Kriederman
NOAA Portland OR Office: Watches - Warnings - Advisories
OR...None. WA...None. PZ...Small Craft Advisory until 11pm PDT Friday for coastal waters from Cape Shoalwater WA to Florence OR out 60 nm.
Small Craft Advisory until 5am PDT Friday for Columbia River Bar.