textproduct: Portland

SYNOPSIS

Warm and dry conditions continue through tomorrow as high pressure slowly loses control of the region. Still expecting upper 80s to around 90 degrees tomorrow, yielding moderate HeatRisk for most lowland locations. Temperatures moderate over the weekend with renewed onshore flow keeping smoke pinned east of the Cascade crests. Near normal summertime weather conditions are anticipated Monday through the middle next week. No precipitation expected during the next 7 days across northwest OR or southwest WA.

DISCUSSION...Tonight through Wednesday

The latest observations across the area indicate lowland temperatures warming into the 80s for most locations with mostly clear skies. Satellite imagery depicts smoke lingering over most locations outside of the coastal areas. Easterly winds have shifted more west to northwesterly as the upper level trough axis shifts east toward the Great Basin. This has helped stop smoke from eastern wildfires from spreading into NW OR and SW WA. Temperatures expected to remain warm with highs in the upper 80s to low 90s expected for interior lowlands and 60s along the coast. A Heat Advisory remains in effect across the inland valleys through this evening highlighting the increased risk of heat-related illnesses. In areas with Air Quality Advisories in effect, it is recommended to keep windows and door shut to prevent smoke from going indoors. Something as simple as a large box fan with a damp towel draped over the front of it can provide effective cooling given the dry airmass in place today if you're seeking some alternative means of relief.

Smoke is expected to linger into Friday but increasing onshore flow is expected to advect cleaner air in from the northwest. Smoke concerns will continue to trend lower except near ongoing wildfires which will persist as crews continue to work on putting them out. The upper level ridge will continue to loosen its grip over the PacNW as it shifts farther east, supporting gradually lower high temperatures into next week. Friday is still expected to be on the warmer side with highs in the upper 80s to around 90 across the interior lowlands. Saturday temps cool a couple degrees into the mid to upper 80s and further on Sunday into the low and mid 80s. Temps along the coast are expected to stay steady in the 60s each afternoon. Marine stratus is expected to influence the coast each night and early morning with low chances for stratus to push past the coast range each night. If you're searching for any rainfall chances headed through the middle to end of next week you're likely out of luck as there are no signs of any appreciable precipitation for western OR and southwestern WA headed into the middle of August. -19

AVIATION...Through 06Z Fri

Satellite imagery and terminal observations as of late Thursday evening depicts smoke beginning to clear out of the area as west/northwest winds aloft push smoke eastward. Still expecting some thin smoke/haze, but it doesn't appear to be thick enough to cause VIS reductions of 5SM or lower. Expect VFR conditions throughout the TAF period for Willamette Valley terminals. Meanwhile, marine stratus has returned to the coast. High confidence for LIFR/IFR conditions through at least 18- 19z Fri along the coast from this stratus as high pressure keeps the clouds low. 40-50% chance at any given hour between 19z Fri-00z Sat for coastal terminals to briefly improve to VFR before marine stratus re-develops in the evening. West/northwesterly winds under 10 kt through the TAF period for all terminals.

KPDX AND APPROACHES...Predominately VFR conditions through the TAF period. Expect some lingering haze/smoke in the vicinity, but light northwesterly winds around 5 kt will help maintain VFR VIS/CIGs at KPDX. -10

MARINE

High pressure at the surface over the eastern Pacific keeps northerly winds in place the remainder of the week through the weekend and into next week as well. Confidence is moderate to high both seas and winds remain below Small Craft criteria through today and Friday. However, winds increase later on Saturday with the NBM projecting a 40-70% chance for at least isolated wind gusts up to 25 kt Saturday evening. Similar probabilities are present during the afternoon/evening hours into early next week so Small Craft Advisories may be needed yet again, mainly across the outer waters. Seas hold around 4-7 feet at 7-8 seconds over the next 5-7 days. -99/10

PQR WATCHES/WARNINGS/ADVISORIES

OR...Heat Advisory until 11 PM PDT this evening for ORZ108>118.

WA...Heat Advisory until 11 PM PDT this evening for WAZ204>208.

PZ...None.