textproduct: Portland

SYNOPSIS

Fairly seasonable early July conditions continue the rest of the week into the weekend. Expect a gradual cooling trend Tuesday and Wednesday as an upper-level trough passes north of the region and increases onshore flow locally while allowing for more prolific morning low clouds, especially Wednesday morning. Temperatures remain fairly close to normal into the first half of the weekend before a ridge of high pressure amplifying to our east allows temperatures to trend warmer into early next week.

LONG TERM...Thursday through Monday

By the end of the week 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 strengthen while an additional trough slowly drops over the eastern Pacific from the the Gulf of Alaska. There still remains a fair amount of uncertainty in the forecast late weekend into early next week due to the exact placement of this developing eastern Pacific trough, but the resulting southwesterly flow shown by most ensemble members likely leads to a gradual warming trend. -99/47

AVIATION

Southwest flow aloft as the region remains under weak upper level troughing. Onshore flow in the lower levels will maintain marine stratus near the central Oregon coast today with IFR to lower-end MVFR CIGs likely to continue at KONP. VFR conditions expected for inland terminals through at least 12z Tuesday with scattered high level clouds. Expect IFR to LIFR marine stratus to push onshore again this evening along the coast, with chances for low-end MVFR to IFR conditions increasing to over 60% after 02-04z Tue. There is around a 10-20% chance for stratus with MVFR CIGs to reach inland terminals after 12z Tue. Northwest winds increase this afternoon with gusts up to 20 kt, strongest at the coast.

KPDX AND APPROACHES...Predominately VFR conditions expected through at least 12z Tuesday. There are low chances (10-20%) of MVFR stratus developing after 12z Tue. Northwest winds expected to increase this afternoon to around 6-8 kt. /DH

MARINE

High pressure will maintain north to northwesterly winds across the coastal waters through the week. Winds around 15-20 kt this afternoon will decrease through Tuesday as a weak cold front dropping out of the of Gulf of Alaska is expected to fall apart. Seas around 6 to 7 ft are also expected to subside to around 4 to 5 ft through Wednesday. Pressure gradients briefly tighten again both Wednesday and Thursday evenings, with gusts generally up to 15-25 kt, strongest across the coastal waters south of Cape Foulweather. Another weak front will likely approach the waters on Friday returning more benign conditions. /DH

PQR WATCHES/WARNINGS/ADVISORIES

OR...None. WA...None. PZ...None.