Area Forecast Discussion
Issued by NWS Portland, OR

Current Version |  Previous Version |  Graphics & Text |  Print | Product List |  Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
606 FXUS66 KPQR 181001 AAA AFDPQR Area Forecast Discussion National Weather Service Portland OR 300 AM PDT Thu Jul 18 2024 .SYNOPSIS...
-- Changed Discussion --
Generally, high pressure rebuilds with above-average temperatures through the weekend, with mostly sunny skies inland and morning clouds along the coast. A cooling trend will likely bring temperatures closer to seasonable normals early next week.
-- End Changed Discussion --
&& .SHORT TERM...
-- Changed Discussion --
Today through Saturday...High pressure over the area today resulting in dry and warm conditions. Marine stratus along the coast is gradually pushing inland this morning, but is expected to break up and clear for much of the area by the afternoon. Temperatures warm back into the upper 80s to lower 90s for the interior lowlands. Onshore flow increases this evening bringing cool breezes. Upper shortwave trough moves over the region tonight deepening the marine layer somewhat. Expect similar conditions for Friday. The upper level ridge begins to rebuild on Friday, and amplifies over the Pacific NW on Saturday. Very likely (50-70%) that highs inland reach the mid 90s, and pushing triple digits near Hood River. This may lead to localized areas of major HeatRisk from the Portland metro through the Columbia River Gorge. /DH
-- End Changed Discussion --
&& .LONG TERM...
-- Changed Discussion --
Sunday through Wednesday...Upper level ridge begins to shift back east on Sunday. Deterministic models showing a weak upper shortwave trough lifting north early Sunday; with it NBM showing slight chances of showers for the coast through Sunday morning. Temperatures inland remain warm with highs likely 85-90 degrees. Then, cooler weather likely early next week. WPC Cluster analysis maintains good agreement among ensemble guidance as it shows upper level troughing sliding into the Pacific NW. How cool it gets will depend on the location of the upper low which will be dropping down from the Gulf of Alaska. Most guidance suggests it remains centered north as it moves into British Columbia. Temps will likely trend closer toward seasonal normals. Dry weather expected to continue. /DH
-- End Changed Discussion --
&& .AVIATION...
-- Changed Discussion --
High pressure over the region, with mild southwest flow aloft, will maintain VFR under clear skies. Do have MVFR marine stratus along the coast extending inland through the valleys, with cloud tops around 2000 ft. This stratus will reach into the south Willamette Valley, affecting areas from KS12 and KCVO southward through KEUG and K77S until 17Z. Also, will have areas of MVFR stratus along the Columbia River as far inland as KPDX and KTTD early this am, as well as Cowlitz Valley. This marine stratus will break up and dissipate, burning back to the coast and beaches by early afternoon. Stratus will surge ashore early this evening, with widespread MVFR CIGS along the coast. PDX AND APPROACHES...High pressure over region keeps the ops area under clear skies today. Areas MVFR stratus expected in/around KPDX to KTTD as well as across Clark County from 12Z to 16Z. /Rockey
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
Weak high pressure today, with light winds. But, this high will strengthen tonight and Friday, with increasing north to northwest winds on the waters at that time. Still, pressure gradients not all that tight until Sat. Should see northerly winds gusting 20 to 25 kt on Sat and Sun. Seas mostly stay in the 3 to 5 ft range, with a mix of variable period swell.
-- End Changed Discussion --
&& .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...None. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland www.twitter.com/NWSPortland