Marine Weather Net

Cape Lookout to Florence OR between 150 and 250 NM Offshore Forecast


TONIGHT

VARIABLE
LESS
THAN
10 KNOTS

THU

S
WINDS
5 - 15
KNOTS

THU NIGHT

SSW
WINDS
10 - 15
KNOTS

FRI

W
WINDS
5 - 10
KNOTS

The Marine Weather Forecast In Detail:
PZZ910 Forecast Issued: 234 PM PDT Wed Jul 17 2024

Tonight...Variable Winds Less Than 10 Kt, Becoming W To Sw. Seas 5 To 6 Ft.
Thu...S Winds 5 To 15 Kt. Seas 4 To 6 Ft.
Thu Night...S To Sw Winds 10 To 15 Kt. Seas 4 To 6 Ft.
Fri...W Winds 5 To 10 Kt. Seas 5 To 6 Ft.
Fri Night...Nw Winds 5 To 10 Kt. Seas 4 To 5 Ft.
Sat...N To Nw Winds 10 To 15 Kt. Seas 4 To 5 Ft.
Sat Night...N To Nw Winds 10 To 20 Kt. Seas 4 To 6 Ft.
Sun...Nw Winds 10 To 20 Kt. Seas 5 To 6 Ft.
Sun Night...N To Nw Winds 10 To 20 Kt. Seas 4 To 6 Ft.
Mon...N To Nw Winds 10 To 20 Kt. Seas 4 To 6 Ft.
Mon Night...N To Nw Winds 15 To 20 Kt. Seas 4 To 6 Ft.
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Area Forecast Discussion
National Weather Service Portland OR
217pm PDT Wednesday July 17 2024

Synopsis
An exiting upper level trough will bring a 15-20% chance of thunderstorms over the south WA Cascades, Columbia River Gorge, Upper Hood River Valley, and north Oregon Cascades through this afternoon. This evening onward, high pressure will re-build and return quieter weather. We'll still see above- average temperatures through the weekend, with mostly sunny skies and morning clouds along the coast. Early next week, a cooling trend will likely bring temperatures close to normal.

.SHORT TERM...Today through Friday night...Water vapor satellite imagery as of 2pm PDT Wednesday depicts the upper level trough gradually exiting our area. Instability from this upper trough will be conducive for convection this afternoon, leading to a 15-20% chance of thunderstorms for the south WA Cascades, Columbia River Gorge, Upper Hood River Valley, and north Oregon Cascades. The Red Flag Warnings in these areas were extended through 5pm PDT Wednesday to cover the potential for fire starts due to lightning and critically dry fuels. So far today, radar imagery has detected several lightning strikes in Hood River County and areas along the Skamania/Klickitat/Yakima County border. Note that any thunderstorms that develop this afternoon have the potential for producing outflow winds with gusts up to 40 mph, which could result in erratic fire spread.

The upper level trough will be far removed from our area by this evening, which should end the threat for thunderstorms. High pressure will begin to re-build, returning quieter weather. Tonight, most locations will be clear except along the coast where moistening conditions will return a marine layer. Expect high temperatures tomorrow (Thursday) and Friday in the upper 80s to low 90s for interior lowland valleys. NBM probabilities for temperatures above 90 in the Willamette Valley are around 45-65% on Thursday and 75-85% on Friday.

Humidities for interior locations tomorrow are forecast to be above critical thresholds, around 30-35%, however further drying may bring humidities down to 25-30% on Friday. We maintain onshore flow, with westerly winds shifting north/northwest on Friday when high pressure re-builds in the NE Pacific. Fortunately, Winds are not expected to be impactful, but the strongest winds will be in the Columbia River Gorge and Upper Hood River Valley where winds could gust to 20-25 mph. -Alviz

Long Term
Saturday through Tuesday Night...500 mb WPC Cluster analysis maintains good agreement among ensemble guidance as it shows an the upper level ridge anchored over the Great Basin, amplifying through the weekend, before a low coming in from the NE Pacific cause the high to weaken an push the ridge axis eastward towards the start of the upcoming week. This will likely result in temperatures warming on Saturday, before a slight cooling trend for the start of next week. Daytime highs on Saturday look to remain a few degrees above normal, with the Willamette Valley in the low to mid 90s, low 70s to low 80s for the Coast and mid 80s to mid 90s for the Cascades. For the start of next week, temperatures look to cool closer towards seasonal normals. This cooling trend can also be seen in the Climate Prediction Center (CPC) 6-10 day outlook, which does show portions of NW Oregon and SW Washington having temperatures near normal. /42

Marine
Showers and thunderstorms have diminished across the coastal waters this afternoon as an upper level disturbance continues to push north of the region. Weak surface low pressure will linger off the Washington coast tonight and maintain 10-15 kt southerly breezes across the waters into this evening. Expect mostly light winds Thursday and Friday in the absence of strongly defined pressure gradient. Moderate to strong northerly breezes will then return this weekend as stronger high pressure builds offshore. Seas will generally remain at or below 5 ft through the period in the presence of a few minor mid and long period background swells out of the west and south respectively. /CB

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