Cape Blanco OR to Point St. George CA from 10 to 60 NM Marine Forecast
|Today...E Wind 5 Kt...Veering To W Early In The Afternoon, Then...Veering To Nw Late Afternoon. Wind Waves 2 Ft Or Less. Nw Swell 8 To 9 Ft At 13 Seconds.|
|Tonight...N Wind 5 To 10 Kt...Backing To Nw Early In The Morning. Wind Waves 2 Ft Or Less. W Swell 7 To 8 Ft At 13 Seconds.|
|Sun...Nw Wind 5 Kt...Backing To S In The Late Morning And Afternoon. Wind Waves 2 Ft Or Less. Nw Swell 7 Ft At 13 Seconds.|
|Sun Night...Northern Portion, S Wind 10 To 15 Kt... Rising To 25 Kt After Midnight. Southern Portion, S Wind 5 Kt...Rising To 15 Kt After Midnight. Wind Waves 2 Ft Or Less...Becoming 3 To 6 Ft After Midnight. Nw Swell 7 To 8 Ft. Chance Of Rain.|
|Mon...S Wind 20 Kt...Becoming Nw 5 To 10 Kt In The Afternoon. Wind Waves 4 To 6 Ft. Nw Swell 12 To 15 Ft. Rain Likely.|
|Mon Night...N Wind 10 Kt...Veering To Ne 15 To 20 Kt After Midnight. Wind Waves 3 To 4 Ft. Nw Swell 13 To 15 Ft.|
|Tue...N Wind 25 Kt...Rising To 30 Kt In The Afternoon And Evening, Then...Easing To 20 Kt After Midnight. Wind Waves 6 Ft... Building To 8 To 9 Ft. Nw Swell 11 Ft...Subsiding To 8 Ft.|
|Wed...Ne Wind 5 Kt...Veering To S. Wind Waves 5 Ft In The Morning...Becoming 2 Ft Or Less. Nw Swell 6 Ft...Building To W 9 Ft.|
| Area Forecast Discussion|
National Weather Service Medford OR
800am PST Sat Nov 28 2020
28/12Z NAM in. 28/12Z GFS in through 84hr.
There are extensive areas of fog/freezing fog over the west side valleys this morning. A cloud band associated with an incoming front is also moving through the area. No precipitation related to the front has been recorded.
The flow aloft over the Pacific northwest is quasizonal, and a short wave embedded in the flow is pushing a weak front onshore at this time. This will be a dry front for almost all of the Medford forecast area. Some very light precipitation may fall near Reedsport, but that will be about it. While the front will induce some mixing, it won't be enough to end the stagnant weather pattern currently in place over the area.
Weak ridging will return Saturday night into Sunday. This will allow the stagnant conditions to continue. Inversions over the valleys will be slow to burn off in the daytime and some areas may not clear at all. Winds in the valleys will be light, but above the inversions, dry easterly flow aloft will keep the ridges clear and relatively warm.
A stronger short wave will move in Monday, and this will push a front onshore late Sunday night into Monday. This will be the most significant system between now and next Friday, but it will also be on the weak side.
There will be some rain at the coast late Sunday night into Monday morning with some precipitation reaching to the Cascades by late Monday morning. Most of the support for this system will push east of the area Monday afternoon and precipitation will end by Monday evening. The current forecast shows a tenth to around a third of an inch at the coast and also over to the Cascades north of Crater Lake, with lesser amounts to the south and east. This would result in an inch or so of snow for areas above 4500 feet in the Cascades. The front will weaken as it moves east of the Cascades, so precipitation chances will diminish to less than 15% in parts of Modoc/eastern Lake Counties. The front will induce some mixing in the air mass, and should be enough to end the Air Stagnation Advisory currently in effect.
However, dry weather and air stagnation will return, as another ridge will build into the area Monday. This one will be stronger and, while it won't quite make it to omega block status, it will progress east very slowly, making for a dry week.
Long term discussion...Tuesday 01 Dec through Saturday 05 Dec 2020. Strong upper level ridging will be the dominant weather driver during the extended period. This means another period of stagnant weather with dry conditions and overnight/morning fog for west side valleys. The deterministic GFS/EC solutions attempt to bring fronts into the area, but they all wash out as they move into the strong ridge. Model ensembles and cluster analysis support dry conditions during this time and lend to high confidence in this pattern. This pattern isn't likely to change through at least next weekend. /BR-y
Updated 730am PST Saturday 28 Nov 2020...Seas will remain steep through this morning. A weak cold front will dissipate over the waters north of Cape Blanco today with seas diminishing into Sunday. A warm front will brush past to the north late Sunday, followed by a strong cold front late Sunday night into Monday morning. Gusty south winds and a building long period northwest swell will accompany this frontal passage with gusty winds and possible steep seas hazardous to small craft.
Seas are expected to peak on Monday with a heavy long-period northwest swell of 13 to 18 feet at 15 to 17 seconds. Seas are expected to diminish Tuesday into Wednesday but a thermal trough will develop at the coast with seas likely remaining steep as north north winds increase over the waters. -DW/Sven
.MFR WATCHES/WARNINGS/ADVISORIES... OR...Air Stagnation Advisory until 11am PST Monday for ORZ023>031. Dense Fog Advisory until 10am PST this morning for ORZ023-025. Freezing Fog Advisory until 10am PST this morning for ORZ024-026.
Pacific Coastal Waters...None.