Marine Weather Net

Cascade Head to Florence, OR out 10 NM Marine Forecast


REST OF TODAY

SW
WINDS
5 KNOTS

TONIGHT

N
WINDS
TO 5
KNOTS

WED

N
WINDS
5 KNOTS

WED NIGHT

NW
WINDS
5 KNOTS

The Marine Weather Forecast In Detail:
PZZ255 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 To 5 Kt. Wind Waves Sw 1 Ft At 4 Seconds. Nw Swell 2 Ft At 9 Seconds. Widespread Dense Fog And A Chance Of Showers In The Morning, Then 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...N Wind 5 Kt. Wind Waves N 1 Ft At 4 Seconds. Nw Swell 3 Ft At 9 Seconds. Patchy Dense Fog In The Morning.
Wed Night...Nw Wind 5 Kt. Wind Waves W 1 Ft At 4 Seconds. Nw Swell 3 Ft At 9 Seconds.
Thu...Se Wind 5 Kt, Veering To W In The Afternoon. Wind Waves Se 1 Ft At 4 Seconds, Shifting To The W At 4 Seconds In The Afternoon. Nw Swell 3 Ft At 10 Seconds.
Thu Night...N Wind 5 To 10 Kt. Wind Waves N 1 Ft At 4 Seconds. Nw Swell 3 Ft At 10 Seconds.
Fri...N Wind 5 To 10 Kt. Wind Waves 2 Ft. Nw Swell 3 Ft.
Sat...Nw Wind 5 To 10 Kt. Wind Waves 2 Ft. Nw Swell 4 Ft.
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Area Forecast Discussion
...UPDATED National Weather Service Portland OR
924am PDT Sunday September 25 2022

Updated aviation discussion

Synopsis
High pressure will lead to warm and dry weather through Monday, with plenty of sunshine. Temperatures will warm 10 to 15 degrees above seasonal normals, with inland valleys potentially reaching 90 degrees today and/or Monday. Nigheights will cool off nicely where the wind diminishes, thanks to the dry air mass. The next chance for rain comes midweek as a fast-moving cold front moves in from the Pacific, with a better chance of rain at end of the week.

.SHORT TERM...Today through Tuesday...Latest GOES-West water vapor imagery clearly shows a newly-formed upper level low pressure system just off the southern Oregon coast. While this system appears well defined in water vapor imagery, it is fairly weak and mostly dry. In fact, dry air being entrained into this system appears to be compensating for weakening subsidence associated with the broader upper ridging over the region. The result is roughly the same, as humidity recoveries this morning have only been fair to poor along and above thermal belts. The driest air is where it was this time yesterday morning, over FWZ608, or the Willamette NF in eastern Lane County. The Spirit Lake incident RAWS monitoring conditions near the Cedar Creek Fire climbed to around 50% RH early in the evening but then dried out to around 30% by midnight and has remained near that RH since.

Under clear skies and mostly light winds, it has been a good night for radiational cooling in the valleys. Today will get off to a cool start for the more wind-sheltered valleys where temps will start off the day in the 40s. Meanwhile, today will start milder in the higher, exposed terrain of the Cascades where temps are presently in the 60s due to their exposure to our warm air mass aloft. Most other areas will start the day in the 50s. Temps will rise quickly under abundant sunshine and some degree of offshore flow, and should reach the 80s for much of our forecast area. Coastal areas may struggle to climb above the 70s as any offshore flow there should switch to onshore flow by midday or early afternoon.

Above normal temperatures will continue into Monday, though some models have been hinting that marine seepage may cool off areas near the Coast Range gaps earlier than previously expected. In fact, the 00z GFS (Global Forecast System) shows 850 mb temps actually peaking today around +21 deg C over the Willamette Valley, lowering to around +18 deg C Monday while the Portland metro and Columbia Gorge remain under 850 mb temps around +20 deg C. This appears to be a hint that the marine influence will be greater in our southern zones Monday, leading to higher RH and slightly cooler temps. This may help keep temps in the lower to mid 80s for Eugene and Corvallis Monday, while valley locations north and east of there make a run for 90 degrees. All this said, latest NBM probabilistic guidance only shows about a 15-20% chance for Salem and Portland to reach 90 degrees Sunday and/or Monday.

Low clouds and fog will likely return to the Oregon coast tonight into Monday. Weak offshore flow will likely keep the clouds south of Astoria to start, allowing Monday to be another warm day for Pacific County. Thermal low pressure will expand northward across western OR/WA Monday, focusing more on the Columbia Basin Monday night and Tuesday. This should allow onshore flow to spread across the CWA (County Warning Area) and as a result, low clouds will likely begin to push inland with a deepening marine layer Monday night, with some degree of cloudiness inland Tuesday morning. The enhanced marine influence should lead to more seasonable temperatures Tuesday, with inland valleys mostly in the mid 70s to lower 80s. Weagle

Long Term
Wednesday through Friday...A fast-moving Pacific cold front is expected to reach the Pac NW early Wednesday, and may bring a few showers to our CWA. More likely is occasional drizzle with the rather deep marine layer, especially against the coastal mountains and on the western slopes of the Cascades. Any rainfall amounts appear light at this point. Will be much cooler, with highs in the 60s for most areas, though lower 70s still expected for inland valleys. Onshore flow with a few showers lingers into Thursday before dry and seasonable weather develops for Friday. But, if computer models are right, will see another front arriving early next weekend, with a better chance of rain. /Rockey

Marine
Buoy observations continue to show northerly winds hovering around 15 to 20 kt with seas ranging between 5 to 7 ft through today. Starting Monday, the surface pressure gradient over the coastal waters will weaken through Tuesday, resulting in northerly winds around 8 to 10 kt while seas hover around 3 to 5 ft. Tuesday night, a cold front is set to push across the waters and will result in a southerly wind shift across all waters. Behind this front, a fresh swell will build seas towards 9 to 11 ft across the coastal waters.

Also, a strong ebb cycle is expected to start Tuesday night and continue through Friday. Building seas and a strong ebb cycle will likely result in hazardous bar conditions. /42

For information about recent marine zone changes, go online to: https://www.weather.gov/pqr/marinezone

NOAA Portland OR Office: Watches - Warnings - Advisories
OR...None. WA...None. PZ...None.