


Area Forecast Discussion
Issued by NWS Portland, OR
Issued by NWS Portland, OR
766 FXUS66 KPQR 011742 AAA AFDPQR Area Forecast Discussion...UPDATED National Weather Service Portland OR 1042 AM PDT Tue Jul 1 2025 Updated aviation discussion. .SYNOPSIS... Hot and dry weather continues today, though cooler than Monday. Highs will still reach into the upper 80s to around 90 degrees across the interior. Isolated thunderstorms remain possible across the Lane and Linn County Cascades this afternoon and evening. A cooling trend begins midweek, bringing more seasonable conditions through the weekend. There are signs that warmer temperatures may return early next week as upper level ridging begins to rebuild. && .DISCUSSION...Now through Monday...As of early this morning, skies are mostly clear across northwest Oregon and southwest Washington, with marine stratus confided to the immediate coast. The strong upper ridge that brought Mondays peak heat is now beginning to shift eastward as a weak trough approaches from the Pacific. Temperatures today will still be warm but a few degrees lower than yesterday. Inland highs are expected to top out in the upper 80s to near 90 degrees. The hottest locations on Monday reached the mid 90s, but those values are not expected to repeat today. There remains a 15-25% chance for isolated thunderstorms across the Lane and Linn County Cascades this afternoon and evening. A weak shortwave rotating around a cutoff low over California may bring just enough lift and monsoonal moisture into central Oregon to support convective development. Any storms that form could produce lightning, gusty outflow winds, and small hail, posing a hazard to recreation and outdoor activity in the Cascades. By tonight and into Wednesday, the upper ridge continues to weaken and shift east as troughing takes hold across the Pacific Northwest. This will bring cooler, more stable conditions with a return to weak onshore flow. Expect inland highs in the low 80s and coastal areas holding in the 60s to low 70s. This cooler pattern appears likely to persist into the holiday weekend, with ensemble guidance in strong agreement on broad troughing through at least Saturday. Highs in the Willamette Valley are expected to range from the upper 70s to low 80s, which is near to slightly above early July climatological norms. Persistent onshore flow may also promote morning marine stratus, especially in low lying interior areas. By Monday of next week, ensemble guidance begins to suggest a transition toward zonal flow, with indications of upper level ridging re-establishing over the western US. However, ensemble clusters begin to diverge significantly beyond Sunday, introducing forecast uncertainty for the early part of next week. Inland temperatures may begin to rebound, potentially returning to the upper 80s, though confidence in the magnitude and timing of this warming is still limited. Surface winds are expected to remain north to northwesterly both along the coast and inland, which may help maintain marine influence in some areas. ~Hall && .AVIATION...Latest satellite imagery shows a continued narrow strip of marine stratus resulting in IFR/LIFR cigs at KAST and KONP. Coastal stratus coverage will diminish through the day, however IFR cigs will remain favored at KONP while breakouts to VFR are more likely to the north, including KAST. Inland, VFR conditions will continue under mostly clear skies. Isolated thunderstorms along and east of the Cascade crest later this afternoon may result in high clouds associated with convective debris, however cigs would remain VFR for inland terminals. Diurnal winds out of the N to NW will increase to 15-20 kt gusting to 25 kt along the coast, and to 10-15 kt with gusts reaching 20 kt along the Lower Columbia including KPDX this afternoon. Winds will ease tonight. PDX AND APPROACHES...VFR conditions will continue through 18z Wednesday under mostly clear skies. Diurnal NW winds increase to 10-15 kt after 18-20z Tue, with gusts of 20-25 kt this afternoon and evening from 21z Tue-04z Wed, before subsiding to 8-10 kt after 06z Wed. -TK/Picard && .MARINE...Persistent surface high pressure offshore will see northerly to north-northwesterly winds persist across the waters throughout the next week. Breeziest conditions are expected today, with gusts up to 25 kt through this evening most likely south of Cape Foulweather, easing to 15-18 kt or less by tomorrow. Small Craft Advisories remain in effect through 5 PM this afternoon north of Cape Falcon, and through 11 PM this evening from Cape Falcon south to Florence. Choppy seas of 7-9 ft at 7-8 seconds will continue through today, before subsiding to 3-6 ft tomorrow through the weekend as winds weaken. -Picard && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory until 5 PM PDT this afternoon for PZZ251- 271. Small Craft Advisory until 11 PM PDT this evening for PZZ252-253-272-273. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland