Area Forecast Discussion
Issued by NWS Portland, OR

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151 FXUS66 KPQR 122029 AFDPQR Area Forecast Discussion National Weather Service Portland OR 129 PM PDT Wed Jun 12 2024 .SYNOPSIS...
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High pressure offshore maintains seasonably warm and dry conditions through Thursday. Low pressure then brings cool and showery weather Friday into the early part of next week, with a slight chance of thunderstorms Saturday into Sunday. Temperatures look to rebound near or above seasonal normals by the middle of next week.
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&& .SHORT TERM...
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Now through Friday Night...Plenty of sunshine across the area today as morning cloud cover has been scoured out by dry northerly flow with high pressure anchored offshore as of early Wednesday afternoon. This has allowed temperatures to climb well into the 70s across the interior lowlands. Not much change expected through Thursday as high pressure remains offshore and maintains warm and dry weather. Continued drying of the air mass will result in less cloud cover tonight into Thursday morning, which will in turn allow temperatures to climb a couple degrees higher on Thursday afternoon. Generally expect highs to top out in the upper 70s away from the coast, with probabilistic guidance showing a 25-30 percent chance to reach 80s degrees across the Portland metro for Thursday. Expect a pattern shift back towards cooler and cloudier weather on Friday as an upper level trough currently over the Gulf of Alaska descends upon the Pacific Northwest. This will drop temperatures back near or slightly below seasonal norms with highs in the upper 60s or low 70s and also bring a chance of showers as a weak front moves through the area. Shower chances look to be generally confined to areas along and north of a Lincoln City-Portland-Mt St Helens line through Friday evening before more widespread shower activity spreads across the area Friday night. Model QPF remains on the light side, ranging from 0.25-0.50" in the higher terrain but generally closer to a tenth of an inch or less for all other locations through Saturday morning. /CB .LONG TERM...Saturday through Wednesday...WPC ensemble clusters remain in strong agreement on maintaining upper level troughing and a resulting cool, cloudy and showery pattern over the Pacific Northwest this weekend through the early part of next week. This is reflected in ensemble temperature forecasts which keep the area below normal with highs in the 60s through at least Monday. Cold air aloft will maintain showery conditions into Tuesday, though these look to be mainly spotty in nature with model QPF amounts remaining light through the period. Guidance indicates a 15-25 percent chance for a few rumbles of thunder across the north both Saturday and Sunday afternoon, which will largely be dependent on if there are enough sun breaks to allow for adequate destabilization. Temperatures look to rebound into the 70s next Tuesday and Wednesday as the majority of ensemble clusters depict the trough starting to shift east of the region by midweek. /CB
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&& .AVIATION...
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High pressure will keep VFR conditions and clear skies throughout the period for most terminals. Only exception is the potential (10-30% probability) of MVFR stratus forming in KAST between 04Z-18Z Thursday, but it looks to be infrequent and short-lived if anything is to form. North northwesterly winds continue to increase this afternoon throughout all the terminals, with gusts up to 30 kt along the coast and up to 20 to 25 kt inland, expected to last until 03Z-06Z Thursday. Winds will become fairly light thereafter. PDX AND APPROACHES...Predominantly VFR and clear skies throughout the TAF period. North westerly winds with gusts up to 20 kt expected between until 06Z-08Z Thursday. Winds will become light again thereafter. -JH
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&& .MARINE...
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A Small Craft Advisory for the Columbia Bar will remain in effect until midnight tonight, with winds gusting to 20 to 25 kt. Wind-driven Small Craft Advisory will be maintained until Thursday night for the inner and outer waters. Seas are currently around 7-9 feet at 10 seconds, with northerly winds gusting up to 25 kt, increasing to near 30 kt this evening into tonight. Thursday, winds will gust up to 25 kt, then decrease below Small Craft Advisory criteria by Thursday night. Seas will have settled to 5 to 7 ft around this time, but may remain choppy. Next front will arrive late Friday, shifting winds back to westerly at 10 to 15 kt for late Friday into early Sunday. -JH
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&& .PQR WATCHES/WARNINGS/ADVISORIES...
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OR...None. WA...None. PZ...Small Craft Advisory until midnight PDT tonight for PZZ210. Small Craft Advisory until 11 PM PDT Thursday for PZZ251>253- 271>273.
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