textproduct: Portland

SYNOPSIS

The next seven days are highlighted by above normal temperatures with low-level onshore flow remaining in place. Mainly dry weather will continue through the weekend, aside from late Wednesday into Thursday when chances for rain showers and isolated thunderstorms increase with an approaching upper level low.

LONG TERM...Friday through Monday night

Confidence in the forecast actually increases a bit Friday and into the weekend despite total model spread for temperatures remaining large. Overall, model ensembles are in good agreement for dry and warm conditions Friday through the upcoming weekend with continued low-level onshore flow and southwest flow aloft. The main uncertainty in the long term forecast is exact high temperatures for inland valleys, which could range anywhere from the lower 80s to near 100 degrees. The most likely outcome is for highs somewhere in the mid 80s to lower 90s.

As of this forecast, Sunday and Monday look like they could be similarly warm with highs in the 90s for the interior lowlands. Chances for Sunday highs to reach or exceed 90 degrees are 40-60% for inland valleys, except 30-40% over the Cowlitz Valley and lower Columbia. On Monday, chances are 40-70% for all interior lowlands. Chances for 100 degrees or greater both days are locally 5-10% around the Portland metro and into the Columbia River Gorge. Major HeatRisk probabilities for Sunday range from 10-20% and on Monday from 15- 30%. Extreme heat is unlikely at this time but there remains uncertainty, check in for the latest updates. It is also worth noting the coast would remain much cooler than inland areas regardless of the outcome due to light onshore winds. Beyond the seven day forecast, it is possible the warm and dry conditions will persist beyond Monday. -19/23

AVIATION

VFR conditions under mostly clear skies expected for all inland locations through the TAF period, while coastal will continue to improve towards VFR over the next few hours. Around 03Z-05Z Wednesday, IFR/LIFR conditions are expected to return to the coast as shallow, marine stratus returns. There is a 40-60% chance for IFR conditions and a 20-40% chance for LIFR conditions. These lowered flight conditions along the coast are expected to persist through around 15Z-17Z Wednesday with conditions expected to improve towards VFR around that time.

North/northwest winds to 5-10 kt inland and 7-12 kt at the coast around 18Z-20Z Tuesday. Coastal terminals may see gusts up to 20 kt. Light northerly winds return overnight across the airspace.

KPDX AND APPROACHES...VFR under mostly clear skies and northwesterly winds around 5-8 kt. /42

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 mainly in the 4-6 foot range but could see some 7 foot seas at 8-10 seconds. Isolated steep and hazardous seas but not enough to issue a Small Craft Advisory (SCA).

A SCA is in effect from 3AM to 9AM Wednesday morning for the Columbia River Bar for rough seas due to a very strong ebb current leading to seas of 6 to 8 ft. -19

PQR WATCHES/WARNINGS/ADVISORIES

OR...None. WA...None. PZ...Small Craft Advisory from 3 AM to 9 AM PDT Wednesday for PZZ210.