textproduct: Portland

SYNOPSIS

Upper level ridging and low-level offshore flow develops today, continuing into Tuesday, bringing warmer and sunnier conditions with high temperatures in the lower 90s today and upper 80s Tuesday across the interior lowlands. Wildfire smoke will also begin to increase over the Columbia River Gorge, Upper Hood River Valley, and the greater Portland/Vancouver metro area this morning and then linger through Tuesday; however smoke is not expected to be dense for most locations. Onshore flow arrives by Wednesday and continues thereafter, which will clear any lingering smoke out of the area and bring cooler, more seasonable temperatures through the end of the week and into the weekend.

LONG TERM...Wednesday through Sunday

Confidence remains high heading into the latter half of the week and into the weekend. Cluster analysis is heavily favoring troughing over the PacNW and western Canada with several embedded impulses reinforcing this pattern for several days. This will bring a significant downward trend in temperatures starting Wednesday with highs close to average then gradually dropping into the uppers 70s Thursday and Friday and possibly the mid 70s by Saturday. Precipitation signals remain weak but the best chance for light rain looks to be Saturday, though there is significant model spread this far out. Could see some light drizzle associated with weak frontal passages Thursday morning and a better chance Saturday. -19

AVIATION...12Z TAFs

North winds have kept marine stratus just off the coast but have started to see some lower clouds develop right along the strip. This is supporting LIFR conditions at KAST and MVFR conditions at KONP. Guidance is struggling with this set-up with just slight changes in the wind direction likely supporting drastic changes in CIGs and therefore flight level along the coast. Could see intermittent CIG restrictions through 16z along the coast. Inland conditions likely remain VFR though guidance does suggest some stratus developing in the eastern Willamette Valley and Portland metro. Could see some brief CIG impacts at KSLE, KEUG, KTTD and maybe KPDX between through 16-18z.

North/northeast winds through the TAF period. Expect breezy winds gusting around of 20 kt at KONP. Around 18-20Z, easterly winds around 8-11 kt are expected to develop at KTTD and KPDX as offshore winds develop through the Columbia River Gorge. The north/northeast winds will also push some wildfire smoke/haze into the Willamette Valley.

Smoke/haze will have the potential reduce vertical and slantwise visibilities at times. In addition, temperatures are expected to warm into the lower 90s this afternoon at the inland TAF sites, so be aware of high density altitude which may reduce aircraft performance.

KPDX AND APPROACHES...North/northeast winds through the TAF period with more easterly winds developing around 18-20Z. Expect 8-11 kt to develop near and east of the terminal as easterly winds develop through the Columbia River Gorge. Smoke/haze will have the potential reduce vertical and slantwise visibilities at times. In addition, temperatures are expected to warm into the lower 90s this afternoon at the inland TAF sites, so be aware of high density altitude which may reduce aircraft performance. -19/42

MARINE

Gusty northerly winds persist through the afternoon across all waters with gusts up to 25 kt expected. Winds decrease from from south to north this evening. The Small Craft Advisory (SCA) from Florence to Cape Falcon will drop off first at 5 PM and the SCA for waters north of Cape Falcon to Cape Shoalwater and the Columbia River Bar are expected to end at 8 PM as winds decrease.

A southerly wind reversal arrives early Tuesday morning over the inner waters with gusts up to 15-20 kt expected by Tuesday afternoon over the northern inner waters. This will also bring increasing chances for marine fog beginning early Tuesday morning, especially over the inner waters. Visibilities may fall below 1 SM at times as the southerly winds develop and upwelling occurs. Aside from the increasing winds and potential marine fog, significant wave heights look to remain relatively low at around 3 to 5 ft through Friday. -19/23

PQR WATCHES/WARNINGS/ADVISORIES

OR...None.

WA...None.

PZ...Small Craft Advisory from 8 AM this morning to 8 PM PDT this evening for PZZ210.

Small Craft Advisory until 8 PM PDT this evening for PZZ251- 271.

Small Craft Advisory until 5 PM PDT this afternoon for PZZ252- 253-272-273.