textproduct: Portland

SYNOPSIS

Warm and sunny conditions continue through the remainder of the week. High pressure today will result in the warmest temperatures this week. This will result in localized Moderate HeatRisk across the inner Portland Metro, Columbia River Gorge, and Upper Hood River Valley. An upper-level trough moving into British Columbia tomorrow will cool temperatures a few degrees and also bring a 15-20% chance for light rain along the south Washington and north Oregon coast on Wednesday. Broad troughing will continue through the week and bring persistent onshore flow, which will maintain seasonable temperatures.

LONG TERM...Thursday through Sunday

Thursday, most ensemble members show the aforementioned trough weakening as it continues to move eastward through British Columbia and into Alberta. As the trough looses synoptic influence over the Pac NW, the Great Basin high is expected to briefly strengthen thus returning dry, zonal flow over the region. However, the zonal flow looks to be rather short lived as by the latter part of the week, ensemble members are showing additional troughing moving down from the Gulf of Alaska into the northeast Pacific/British Columbia region. There still remains a fair amount of uncertainty in the forecast for the latter part of this week and into the weekend as to the exact placement and magnitude of this eastern Pacific trough, but ensembles are keeping this system well to our north to keep us dry, with near to slightly cooler than normal temperatures. /42

AVIATION

Largely VFR conditions continue across the airspace and are expected to persist through the TAF period. Inland locations are expected to maintain VFR conditions, but there is a very low probability (5-10%) chance of a brief period of MVFR conditions developing within the Willamette Valley through 18Z Monday. North/northwest winds 5-10 kt, before becoming light and variable around 02-04Z Tuesday.

For coastal locations, IFR/LIFR will persist through the majority of the TAF period. Some improvement is expected along the coast starting around 19Z Monday, but will likely be limited to areas between KAST and KTMK. KONP has a 15% chance of a brief period of IFR conditions, but any improvement will be short lived. IFR to LIFR conditions are expected to return to the coast around 01-04Z Tuesday. North/northwest winds build to 10-15 kt with gusts near 20 kt through around 04Z-06Z Tuesday.

KPDX AND APPROACHES...VFR conditions expected to dominate through the TAF period. North/northwest winds 5-10 kt, before becoming light and variable around 02-04Z Tuesday. /42

MARINE

High pressure over the region is resulting gusty northerly winds across all waters as gusts of 20-25 kt and seas of 6 to 8 ft are currently being observed this morning. Will maintain the current Small Craft Advisory through early this morning. However, a pattern change is expected to occur today as a broad, upper level Alaskan trough moves south/southeast into western Canada. This will result in both winds and seas subsiding. The northern waters will ease first, following by the central and lastly the southern. Expect northerly winds to persist, with gusts below 15 kt and seas of 5 to 7 ft through the remainder of the week. /42

PQR WATCHES/WARNINGS/ADVISORIES

OR...None. WA...None. PZ...Small Craft Advisory until 11 AM PDT this morning for PZZ251>253-271>273.