textproduct: Portland

SYNOPSIS

Another warm day expected before a brief pattern shift to end the work week. Rain chances increase tonight into Thursday with a slight chance (10-20%) for thunderstorms into Thursday morning. Rain accumulation will generally be orographically driven. Drying occurs starting Friday through the weekend as temperatures heat up once again. Moderate HeatRisk forecast for urban areas on Sunday and Monday.

LONG TERM...Saturday through Tuesday

WPC cluster analysis shows decent agreement in the 500 mb pattern heading into the weekend. Ridging over the central CONUS is expected to rebuild into the PacNW, supporting a warming trend Saturday and into early next week. The interior lowlands can expected highs in the mid to upper 80s on Saturday, building into the low 90s for Sunday and Monday. In this pattern, marine stratus is likely, especially along the coast though it could transition down the Columbia River into the interior lowlands. If cloud cover becomes pervasive, it will have an impact on high temperatures and minimum humidity. There is some spread among the NBM in exact high temperatures, ranging from the mid 80s to upper 90s in the 10th-90th percentiles so could see adjustments moving forward. Moderate HeatRisk is currently forecast across the interior lowlands, including the Cascade foothills, for both of these days. Chances for major HeatRisk are generally 10-30% for the Portland metro and Columbia River Gorge. Warm temperatures are expected to continue into the middle of next week as models continue to anchor the ridge over the CONUS. -19/27

AVIATION

Southerly flow aloft will continue as an upper level low spins offshore. VFR conditions expected to persist inland while marine stratus persists along the coast. Currently MVFR CIGs for both KAST and KONP but could see a brief period of IFR conditions. Conditions are likely to improve toward VFR after 18-19z Wed, especially near KAST, while MVFR probs near KONP persist at around 40-50% through Wed afternoon. Stratus expected to be more widespread tonight. Winds north to Northwest increasing to between 5-10 kt late in the morning.

KPDX AND APPROACHES...VFR expected to continue through the period. Light winds becoming northwest 5-10 kt. -19

MARINE

Benign conditions with a typical summertime pattern expected through the week. Northerly winds 10-15 kt expected with afternoon gusts reaching to around 20 kt each day. Seas could be choppy at times with heights 4-6 feet but could see some 7 foot seas at 8-10 seconds. There is a 30-60% chance for Small Craft Advisory (SCA) criteria winds for all waters Saturday afternoon into Sunday.

A SCA is in effect until 9AM for rough seas within the Columbia River Bar due to a very strong ebb current leading to seas of 6 to 7 ft. Another SCA for strong ebb current and choppy seas Thursday morning from 4 AM to 10 AM. -19

PQR WATCHES/WARNINGS/ADVISORIES

OR...None.

WA...None.

PZ...Small Craft Advisory until 9 AM PDT this morning for PZZ210.

Small Craft Advisory from 4 AM to 10 AM PDT Thursday for PZZ210.