Cape Blanco OR to Point St. George CA out 10 NM Marine Forecast
|Tonight...N Wind 5 To 15 Kt Except Ne 5 Kt Within 5 Nm Of Brookings Southward. Wind Waves 3 Ft In The Evening...Becoming 2 Ft Or Less. Nw Swell 12 To 14 Ft At 15 Seconds.|
|Tue...N Wind 10 To 15 Kt. Within 5 Nm Of Brookings Southward, Ne Wind 5 Kt...Backing To N In The Afternoon. Wind Waves 3 Ft. Nw Swell 9 To 11 Ft At 14 Seconds.|
|Tue Night...Northern Portion, N Wind 10 To 20 Kt... Veering To Ne 5 To 10 Kt After Midnight. Brookings Southward, Ne Wind 5 To 10 Kt...Veering To E In The Late Evening And Overnight. Wind Waves 3 To 4 Ft. Nw Swell 8 Ft At 13 Seconds...Subsiding To 6 Ft At 13 Seconds After Midnight.|
|Wed...Se Wind 5 Kt...Veering To S In The Afternoon. Wind Waves 2 Ft Or Less. Nw Swell 5 Ft.|
|Wed Night...S Wind 5 Kt...Backing To Se After Midnight. Wind Waves 2 Ft Or Less. W Swell 5 Ft... Building To 7 To 8 Ft And W 4 Ft After Midnight.|
|Thu...Ne Wind 5 Kt...Backing To N In The Afternoon. Wind Waves 2 Ft Or Less. W Swell 9 To 10 Ft... Building To 11 To 12 Ft And Sw 1 Ft In The Afternoon.|
|Thu Night...N Wind 5 To 10 Kt. Wind Waves 2 Ft Or Less. W Swell 11 To 12 Ft.|
|Fri...Ne Wind 5 Kt...Backing To N In The Evening, Then...Veering To E After Midnight. Wind Waves 2 Ft Or Less. W Swell 10 Ft... Subsiding To 8 Ft.|
|Sat...S Wind 5 To 10 Kt. Wind Waves 2 Ft Or Less. W Swell 6 Ft... Building To 8 Ft And W 3 Ft.|
| Area Forecast Discussion|
National Weather Service Medford OR
346pm PST Monday Nov 30 2020
Updated Aviation Section.
SHORT TERM...Tonight through Wednesday night..A cold front has moved through the forecast area this morning. Winds aloft associated with the front are of moderate strength as indicated by mountain wave clouds in visible satellite imagery this afternoon. Precipitation with the front has diminished with only a few hundredths being reported over the past 3 hours, focused from the Cascades westward in lingering showers. Showers will continue to diminish this afternoon, and then upper ridging will build through the week. We expect a stagnant air mass to be in place from late Tuesday through Saturday morning at least, with morning valley fog/freezing fog and a minimal amount of mixing in the atmosphere. Conditions will be favorable for pollutants to accumulate in valleys. We're keeping the coast out of the Air Stagnation Advisory for now because we think some north winds will keep that area somewhat mixed, and some isolated areas west of the Cascades (Ashland) and east of the Cascades could see some breezes that keep things mixed better than other valley areas. That said, most inland valleys west of the Cascades and east of the Cascades will be included in the Air Stagnation Advisory, which will be issued today and go into effect Tuesday evening.
Please take extra time for your travels during these periods of fog/freezing fog. Additionally, watch out for slippery walking surfaces where thin layers of ice can accumulate over time when daytime high temperatures in valleys struggle to get out of the 30s.
Long TermThursday morning through Monday night...Not much change in the extended period. Strong upper level ridging remains in the forecast and another period of stagnant air with dry conditions and overnight/morning fog and freezing fog for west side valleys remains the story. Models show a trough approaching the area on Thursday, however, it weakens considerably as it moves into the strong upper ridge. The energy from this trough gets shunted to the south and any moisture gets absorbed by the dry air from the ridge. It does, however, help to shift the pattern some by knocking the ridge down a bit. Another, stronger trough follows late Saturday into Sunday, but it also weakens as it moves into the area. Deterministic models as well as the vast majority of the ensembles maintain dry conditions with this frontal passage. However, it may be enough to mix out some of the stagnant air that will have settled and persisted in the valleys during the previous week.
Looking past next weekend, the National Blend of Models, as well as the vast majority of model ensembles for both the GFS and EC, support mostly dry conditions continuing into the second week of December. Model ensembles indicate a more appreciable change around December 9th-11th. /BR-y
AVIATION...For the 01/00Z TAFs...Conditions have improved this afternoon for most areas. However, MVFR/IFR conditions are occurring in the Rogue and Klamath River Valley, with some higher terrain likely obscured, especially along the Cascades. Expect stratus to redevelop over west side valleys overnight, lowering to fog by morning, resulting in LIFR/IFR conditions. With the recent rain, conditions are favorable for fog at KLMT, but confidence of the extent and duration is not low-to-moderate.
Breezy and gusty winds will begin to ease across the east side and higher terrain overnight. Moderate northerly winds are anticipated to along the coast tomorrow afternoon. -Miles
MARINE...Updated 200pm PST Monday 30 Nov 2020...Gusty northwest winds will continue into this evening as a long period northwest swell moves into the waters. Seas of 14 to 17 feet at 15 to 17 seconds will peak into early this evening. Seas diminish Tuesday into early Wednesday morning, but a thermal trough will develop at the coast. Therefore high and steep seas remain with increasing north winds over the waters. These winds will be strongest south of Gold Beach. Seas then remain steep over the outer waters as they briefly diminish Tuesday night into Wednesday morning. It's possible the steep wind driven seas in the southern outer waters could reach hazardous seas conditions for a 3-6 hour period Tuesday evening, but confidence was not high enough to upgrade at this time. We'll let the next shift take another look at this should future guidance change.
Models remain consistent in indicating a building long period west to northwest swell Wednesday into Thursday with seas rising rapidly. This is likely to combine with incoming tide and a shorter period west-northwest swell at 13 seconds to bring an increased chance of sneaker waves...with highest risk Wednesday but a continued risk as seas build into Thursday. -BR-y/Petrucelli
.MFR WATCHES/WARNINGS/ADVISORIES... OR...Air Stagnation Advisory from 10pm Tuesday to 10am PST Saturday for ORZ029>031. Air Stagnation Advisory from 10pm Tuesday to 10am PST Saturday for ORZ023>026. Beach Hazards Statement from late Tuesday night through late Wednesday night for ORZ021-022.
Pacific Coastal Waters...Small Craft Advisory until 4am PST Wednesday for PZZ370-376. Small Craft Advisory until 4pm PST Tuesday for PZZ350-356.