textproduct: Portland

SYNOPSIS

A warming and drying trend is underway across southwest Washington and northwest Oregon as high pressure gradually builds inland. Temperatures will climb through the weekend and into early next week, with inland highs reaching the upper 80s to low 90s by Monday and Tuesday. Dry weather is expected to persist through at least the middle of next week.

LONG TERM...Monday through Wednesday

Ensemble guidance remains in strong agreement that the ridge will reach its greatest amplitude early next week, supporting the warmest temperatures of the forecast period. While NBM temperature spread has narrowed a degree or two over the past several forecast cycles, confidence that many inland locations will experience highs around 90 degrees Monday through Wednesday has shifted later. While confidence for reaching 90 degrees on Monday has decreased, the potential for 90 degrees remains for Monday through Wednesday. As a result of these changes, there is now higher confidence that Tuesday and Wednesday will be the days of peak heat next week.

Current probabilistic guidance indicates a 30-50% chance of reaching 90 degrees across much of the interior lowlands on Monday afternoon, then a 45-65% chance on Tuesday and Wednesday afternoon. Additionally, there is a 15-30% chance of temperatures reaching 95 degrees on Tuesday and Wednesday, highest across the traditionally warmer valleys. While these temperatures are typical for mid to late July, several consecutive warm afternoons combined with limited overnight cooling will result in pockets of Moderate HeatRisk, particularly for those without adequate cooling or prolonged outdoor exposure.

Little change in the overall pattern is expected through midweek as the ridge remains the dominant weather feature. As a result, dry conditions are forecast to continue with no meaningful precipitation expected across southwest Washington and northwest Oregon.~12

AVIATION

Southwesterly flow aloft continues through 18Z Saturday as a slow-moving low pressure system lingers near Vancouver Island. Expect predominately VFR flight conditions through the TAF period. However, there is a 20-40% chance for ceilings around 2000-3000 ft over the Portland metro and northern Willamette Valley between 12-17Z Saturday, except a 40-50% chance at KTTD.

KPDX AND APPROACHES...Expect mainly VFR flight conditions through 18Z Saturday. However, there is a 20-40% chance for a brief period of MVFR ceilings around 2000-3000 ft between 12-17Z Saturday. Confidence in MVFR ceilings developing Saturday morning is not high enough to reflect in the TAF at this time. Light northwest winds are expected through this evening around 4-7 kt. -23

MARINE

Benign conditions for winds and seas with a typical summertime pattern expected through the week. Northerly winds around 10-15 kt are expected each afternoon/evening with gusts up to approximately 20 kt, except up to 25 kt this weekend to the south of Cape Falcon (60-90% chance). Seas around 4 to 6 ft at 8 seconds will continue through Saturday afternoon. Expect seas to increase slightly to 6 to 9 ft while becoming steeper Saturday night into Sunday, bringing hazardous conditions for small craft.

A Small Craft Advisory remains in effect for the Columbia River Bar for a strong ebb current and choppy seas Thursday morning from 4 AM to 10 AM. -23

PQR WATCHES/WARNINGS/ADVISORIES

OR...None. WA...None. PZ...Small Craft Advisory from 11 AM Saturday to 5 AM PDT Sunday for PZZ253.

Small Craft Advisory from 5 PM Saturday to 5 AM PDT Sunday for PZZ273.