Cascade Head to Florence OR from 10 to 60 NM Marine Forecast
| Rest Of Today...S Wind To 5 Kt. Wind Waves S 1 Ft At 4 Seconds. Nw Swell 3 Ft At 9 Seconds. Widespread Dense Fog In The Morning. Areas Of Dense Fog In The Afternoon. |
| Tonight...N Wind To 5 Kt. Wind Waves N 1 Ft At 4 Seconds. Nw Swell 3 Ft At 9 Seconds. Areas Of Dense Fog In The Evening. Patchy Dense Fog After Midnight. |
| Wed...Ne Wind 5 Kt, Backing To Nw To 5 Kt 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 9 Seconds. Patchy Dense Fog In The Morning. |
| Wed Night...Nw Wind 5 Kt, Backing To Se After Midnight. Wind Waves Nw 1 Ft At 4 Seconds, Shifting To The Se At 4 Seconds After Midnight. Nw Swell 3 Ft At 9 Seconds. |
| Thu...S Wind 5 Kt. Wind Waves S 1 Ft At 4 Seconds. Nw Swell 3 Ft At 10 Seconds. |
| Thu Night...N Wind 5 To 10 Kt. Wind Waves N 2 Ft At 4 Seconds. Nw Swell 3 Ft At 10 Seconds. |
| Fri...N 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. |
| Area Forecast Discussion National Weather Service Portland OR 315am PDT Sat April 20 2024 Synopsis Slightly cooler on Saturday as a cool front moves inland later in the day. This front will bring increasing cloud cover and spotty light rain Saturday afternoon and evening. Trending dry again thereafter with mild conditions returning early next week, warmest on Tuesday. Cool and showery conditions are likely to return late in the week as an upper level trough settles over the area. .SHORT TERM...SATURDAY THROUGH MONDAY NIGHT...Satellite imagery from early Saturday morning depicted clear skies across the region aside from a few thin high clouds. Low-level offshore flow remained in place with easterly winds gusting 20-30 mph over the far eastern Portland metro. Winds were much lighter away from the western Columbia River Gorge. Expect the east Gorge winds to continue through Saturday morning before low-level flow rapidly transitions back onshore in the afternoon. This is in response to an incoming cool front, which will bring increasing cloud cover and some light rain Saturday afternoon. Quantitative Precipitation Forecast amounts are quite low given the weak and fast-moving nature of the front, generally under 0.1" in the lowlands and under 0.5" in the mountains. Expect high temperatures mainly in the 60s, except upper 50s to lower 60s at the coast. High temps will likely occur in the early afternoon before cloud cover thickens up and the cool front arrives. The latest suite of CAM guidance suggests light rain will begin around 11am-noon at the coast and around 3-5pm across the interior lowlands from Kelso to Eugene. Forecast rain amounts are lowest from Salem to Eugene at 0.01-0.03". Expect rain will only last a few hours at any given location. Isolated post-frontal showers will occur behind the front Saturday evening into Sunday morning, mainly in the mountains. A dry weather pattern returns Sunday afternoon into early next week as low-level offshore redevelops and 500mb heigheights rise with an incoming shortwave ridge. Sunday looks to be the coolest day with highs in the 50s at the coast and low 60s inland. Warming back into the upper 60s to lower 70s on Monday, except low to mid 60s at the coast. Model spread via the NBM 1D Viewer is low, suggesting high confidence amongst models and their ensembles in regards to the temperature forecast. Overnight lows look to be a bit too warm for widespread frost concerns at this time. However, cannot rule out some patchy frost in the southern Willamette Valley/Eugene area and outlying rural areas Sunday night as temps attempt dipping into the mid 30s. The NBM is showing a 10-20% chance for temps below 35F from Albany to Eugene, Corvallis to Junction City, and Salmon Creek to Battle Ground. Probabilities fall below 10% for the rest of the lowlands. -TK Long Term TUESDAY THROUGH FRIDAY NIGHT...On Tuesday, the GEFS/ENS/GEPS ensemble means all show southwest flow aloft across western WA/OR on before 500 mb flow veers to the west on Wednesday. The aforementioned wind shift is in response to a weak upper level trough brushing the forecast area to the north. Models and their ensembles suggest mainly dry weather for northwest OR and southwest WA on Tuesday with low chances for light rain showers Tuesday night through Wednesday night (10-20% chance in the lowlands, 20-40% chance in the mountains). Temps look to be a bit above normal, especially on Tuesday when there is a 60-90% chance for high temps at or above 70F. In fact, the NBM is showing a 20% chance for high temps near 80F over the Portland metro during a period of dry east winds. This seems like a bit of a stretch as model soundings do show fairly thick high clouds over the area that day, which will most likely keep highs in the low to mid 70s. Conditions will become noticeably cooler on Thursday as highs fall back into the 50s across the area. This is in response to a cool upper level trough that is set to move overhead late in the week, bringing higher chances for rain. While NBM 6-hr Probability of Precipitation only peak around 50% in the lowlands, 24-hr Probability of Precipitation peak close to 70%. This is due to model timing differences. Only a very small number of ensemble members are showing no rain at all, suggesting rain is likely to occur at some point on Thursday and/or Friday. In addition, the NBM is showing a 30-40% chance for 24-hr rain amounts in excess of 0.25" across all of northwest OR and southwest WA, except 40-60% in the mountains. -TK Marine Southerly winds increase through the day as the front moves through the waters with Small Craft Advisory winds gusting to 25 kt and choppy seas. The front moves ashore this afternoon with westerly winds behind the front, the ease tonight into Sunday as high pressure build over the waters. Northerly winds return late Sunday as a thermal trough strengthens long the south Oregon coast and northern California with winds gusting 20-30 kt Monday and Tuesday. Seas peak around 10 ft, mainly over the northern zones, this afternoon. Seas gradually 6 to 8 ft Sunday through Tuesday but will be choppy. /mh NOAA Portland OR Office: Watches - Warnings - Advisories OR...None. WA...None. PZ...Small Craft Advisory from 11am this morning to 2am PDT Sunday for PZZ251-252-271-272. Small Craft Advisory from 11am this morning to 4pm PDT this afternoon for PZZ253-273. |
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