textproduct: Portland

SYNOPSIS

Very hot temperatures today will persist overnight into Wednesday. Highs in the mid to upper 90s expected inland with chances of highs up to 100 degrees F on Wednesday. Monsoonal moisture will move in on Wednesday which will complicate the forecast. Thunderstorm and shower chances increase on Wednesday, especially in the afternoon with additional daytime heating. Widespread lightning not out of the question. Showers persist into Thursday and cooler temperatures expected through the remainder of the week.

LONG TERM...Thursday night through Tuesday

By Thursday, the ridge begins to weaken as a broader trough moves toward the Pacific Northwest. This should promote a return to more noticeable onshore flow and begin a gradual cooling trend that carries into late week. Temperatures are still likely to remain somewhat above seasonal normals Thursday and Friday, but not to the degree seen earlier in the week. Looking beyond Friday, forecast guidance currently does not show a strong signal for meaningful precipitation, while temperatures trend toward the lower 80s through the weekend and into early next week. -12

AVIATION

VFR flight conditions expected inland today with BKN/OVC high clouds in central OR. Any lingering marine stratus along the coast should dissipate and improve to VFR by 18-19z Tue. A resurgence of marine stratus is likely again tonight into Wednesday morning with IFR/LIFR cigs. At KONP, stratus returns after 00-03z Wed with LIFR conditions favored with a 40-60% chance. Stratus could return at KAST anytime after 06z Wed with a 20-40% chance of IFR and LIFR conditions, higher chances after 12z Wed. North to northwest winds generally less than 10 kts.

KPDX AND APPROACHES...VFR conditions prevail with northwest winds less than 8 kts. -03

MARINE

A typical summertime pattern will continue through the middle of this week with persistent north to northwest winds over the coastal waters. Winds then shift southwest to westerly Thursday into the weekend as weak low pressure develops over the waters. Winds will remain light less than 10-15 kts. Seas will be 3-6 ft at 8-9 seconds through the weekend.

On Wednesday, there is a chance for showers and thunderstorms across all of the waters through the majority of the day and overnight hours. There could be frequent lightning and gusty and erratic winds with any thunderstorm that forms. -03

PQR WATCHES/WARNINGS/ADVISORIES

OR...Heat Advisory until 11 PM PDT Wednesday for ORZ108>115-120>122. Heat Advisory until 11 PM PDT this evening for ORZ117-124. WA...Heat Advisory until 11 PM PDT Wednesday for WAZ204>210. PZ...None.