textproduct: Portland

SYNOPSIS

Expect a warm and dry 4th of July weekend across northwest Oregon and southwest Washington. Temperatures warm up slightly Sunday and Monday as high pressure builds, leading to localized Moderate HeatRisk. An upper-level trough moving into British Columbia Tuesday to Wednesday will cool temperatures a few degrees and bring chances for precipitation along the south Washington and north Oregon coast. Dry and warmer conditions return on Thursday, however persistent onshore flow will help to maintain near normal daytime highs across northwest Oregon and southwest Washington. Make sure to practice water safety when swimming in local rivers.

LONG TERM...Tuesday through Friday

Looking into the middle of next week and towards next weekend, the majority of ensemble members are showing an upper-level trough from the Gulf of Alaska moving down into British Columbia thus compressing The Great Basin upper level high. Given the more northern track of this trough, most places across the area is expected to be dry. An exception would be the south Washington and north Oregon coast where this system favors a 15-30% chance for light rain from Tuesday night to Wednesday, but it should be noted that current QPF totals are minimal at best. Despite the lack of widespread, if any precipitation, onshore flow will increase and support temperatures cooling a few degrees closer to seasonal normals for early July. West-northwesterly winds are generally expected to be light for most areas during this time. However, will see locally breezier along the central Columbia River Gorge and Upper Hood River Valley, where there is a 25-40% chance for at least isolated wind gusts exceeding 40 mph Tuesday and Wednesday. As for the end of next week, most ensemble members show the British Columbia trough weakening as it moves eastward. At the same time, The Great Basin high looks to re-establish itself. This will bring about a return of zonal flow for the Pac NW which will bring warm and dry conditions back into the forecast. /42-10

AVIATION

High pressure will continue to slowly build over the region, resulting in predominately VFR conditions for inland locations through the TAF period. Coastal locations will maintain MVFR conditions through 16Z-19Z Saturday with improvement towards VFR expected afterwards as daytime heating will aid in mixing of the atmosphere. Starting around 06Z-09Z Sunday, marine stratus is expected to return to the coast bringing MVFR flight conditions back into the forecast. Northerly wind less than 10 kt expected through the TAF period, but could see some gusts up to 15 kt for locations in the northern part of the Willamette Valley (KPDX, KVUO and KUAO) from around 00Z-06Z Sunday as well as gusts up to 25 kt along the coast from 18Z Saturday through 06Z Sunday.

KPDX AND APPROACHES...VFR conditions expected to persist through the TAF period. Northerly wind less than 10 kt expected through the TAF period, but could see some gusts up to 15 kt starting around 00Z-05Z Sunday. /42

MARINE

High pressure over the region result in increasing winds and building seas through Monday. Northerly winds will slowly increase through the afternoon and will result in gusts up to 20 kt by this evening and continuing to strengthen with gusts up to 30 kt by Sunday. Seas will also build from 4 to 6 ft towards 6 to 8 ft by Sunday. As a result, have maintained the current suite of Small Craft Advisories through at least Sunday night. High pressure will slowly become displaced towards the start of next week, thus easing overall conditions by Monday night/Tuesday which is expected to persist through the remainder of next week. /42

PQR WATCHES/WARNINGS/ADVISORIES

OR...None. WA...None. PZ...Small Craft Advisory from 11 PM this evening to 11 PM PDT Sunday for PZZ251-271.

Small Craft Advisory from 8 PM this evening to 11 PM PDT Sunday for PZZ252-272.

Small Craft Advisory from 2 PM this afternoon to 11 PM PDT Sunday for PZZ253-273.