textproduct: Portland

SYNOPSIS

Cool onshore flow and persistent cloud cover will maintain below average temperatures over the area through Thursday with little change in the overall weather pattern. Conditions will be mainly dry aside from a few stray sprinkles, mainly over higher terrain. A gradual warming trend develops Friday into the holiday weekend with inland valleys likely warming above 80 degrees by the 4th of July (70-90% chance).

DISCUSSION...Now through Sunday night

Very little change is expected to the overall weather pattern Monday through Thursday. Model ensemble guidance continues to suggest cool onshore flow will persist, with extensive cloud cover each day during the morning and early to mid afternoon hours. This will keep temperatures cooler than average for this time of year with high temperatures ranging from the mid 60s to lower 70s each day, coolest at the coast. The latest forecast is trending mainly dry each day aside from a few stray sprinkles from time to time, mainly over higher terrain.

Conditions will begin trending warmer Friday into the upcoming holiday weekend as weak upper level ridging develops. Although there is still a large degree of total model spread for temperatures, confidence has increased highs will warm to at least 80 degrees for inland valleys by the 4th of July (70-90% chance per the latest NBM guidance). Probabilities for highs of 80 degrees or warmer are similar on July 5th as well. Chances for highs of 90 degrees or warmer over the weekend are generally under 10%, except on Sunday when chances increase to 10-20%. That being said, chances for highs at or above 95 degrees are only 0-5%, suggesting the warmest possible scenario would be somewhere in the lower 90s. In addition, overnight lows are expected to be in the 50s, which will offer excellent relief for those without access to air conditioning regardless of whether or not we wind up in the 80s or lower 90s. -23

AVIATION

Currently as of 18Z Mon, widespread cloud cover bringings IFR/MVFR conditions along the coast and a mix of MVFR/VFR CIGs inland. By 19-21Z Mon, expect prevailing VFR conditions inland and prevailing MVFR conditions along the coast. With a 40-70% chance of MVFR CIGs at coastal terminals through the TAF period, brief VFR CIGs may occur. Around 12Z Tue to the end of the TAF period, there is a 30-40% chance for MVFR CIGs at inland terminals. Otherwise, expect generally northwesterly winds around 5-10 kt during the afternoon, becoming light and westerly to southwesterly overnight.

KPDX AND APPROACHES...Current MVFR CIGs will improve to VFR by 19-20Z Mon, likely lifting to above 4000 ft through the afternoon. There is a 20-30% chance for MVFR CIGs to return by 12-15Z Tue and persist through the morning. Northwest winds around 5-10 kt are expected through the TAF period, likely becoming light and more westerly to southwesterly overnight. ~12

MARINE

Northwest winds around 10 to 20 kt with steep seas near 7 to 9 ft at 9 seconds driven mainly by a fresh northwest swell will continue on Monday. Although weak high pressure will be building over the waters, northwest winds will continue to build the ongoing northwest swell with significant wave heights increasing slightly to 8 to 11 ft Monday afternoon. Seas will be highest over the outer waters. There is a 30-50% chance significant wave heights will peak slightly over 11 ft beyond 40 NM offshore on Monday, mainly to the north of the Columbia River Bar. Northwest winds and a fresh northwest swell then continues Tuesday through Wednesday morning, maintaining steep seas and hazardous conditions for small craft. Winds and seas will ease significantly Wednesday afternoon and evening, with benign conditions expected Thursday and Friday.

Given steep seas and wind gusts upwards of 20 kt, a Small Craft Advisory is in effect for both the inner and outer waters through Tuesday evening. Rough bar conditions are also expected within the main channel of the Columbia River Bar late Monday morning through late Tuesday morning with steep seas around 7 to 10 ft at 9 seconds with northwest winds around 10 to 20 kt. A strong ebb current will occur Tuesday morning, which is when seas are expected to peak near 10 ft. As such, a Small Craft Advisory has been issued for the Columbia River Bar. -23

PQR WATCHES/WARNINGS/ADVISORIES

OR...None. WA...None. PZ...Small Craft Advisory until 11 AM PDT Tuesday for PZZ210.

Small Craft Advisory until 11 PM PDT Tuesday for PZZ251>253- 271>273.