FXUS66 KPQR 190332 AAA AFDPQR Area Forecast Discussion...UPDATED National Weather Service Portland OR 831 PM PDT Thu Jul 18 2024 Updated Aviation Discussion .SYNOPSIS...High pressure continues to rebuild, bringing above-average temperatures with mostly sunny skies inland and morning stratus along the coast. Will see a cooling trend early next week, lowering temperatures closer to seasonable normals. && .SHORT TERM...Today through Saturday...High pressure over the area today resulting in dry and warm conditions, expected to continue into Friday. For today, temperatures are expected to warm back into the upper 80s to lower 90s for the interior lowlands, with onshore flow bringing cool breezes this evening. Friday will have similar conditions, with marine stratus forming (morning) and clearing (afternoon) along the coast, and highs in the low 90s inland. An upper level ridge will begin to rebuild on Friday and amplify over the Pacific NW into Saturday. Saturday, highs inland are expected to reach the mid 90s (60-80% probability), with highs near Hood River pushing triple digits (40-60% probability). This may lead to localized areas of major HeatRisk from the Portland metro through the Columbia River Gorge. -JH && .LONG TERM...Sunday through Wednesday...Upper level ridge begins to shift eastward on Sunday. Deterministic models show a weak upper shortwave trough lifting north early Sunday, bringing a slight chance of showers for the coast through Sunday morning. Sunday may have a slight chance of thunderstorms but confidence still remains low. Temperatures inland remain warm with highs likely between upper and lower 80s Sunday through Wednesday. 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. -JH/DH && .AVIATION...High pressure over the region, with weak southwest flow aloft. Inland locations will have a 25%-35% probability of MVFR conditions with areas near KEUG having a 50%-60% probability for MVFR conditions starting around 08Z-10Z Friday. LIFR/IFR marine stratus and vis will persist along the coast through at least 17Z Friday, with conditions expected to improve towards MVFR/VFR. PDX AND APPROACHES...High pressure over region keeps the ops area under clear skies. 30% probability of MVFR conditions in/around KPDX to KTTD as well as across Clark County, WA starting around 10Z Friday. /42 && .MARINE...Weak high pressure, with light winds. However, a pattern change and northerly wind shift is expected Friday. Still, pressure gradients not all that tight until Saturday. This will result in northerly winds gusting up to 25 kt this weekend. Seas mostly stay in the 3 to 5 ft range, with a mix of variable period swell. && .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