Marine Weather and Tide Forecast for Astoria, OR

SYNOPSIS
Dry and benign weather is expected across the region through much of the next week as high pressure builds over the Northeast Pacific, bringing a warming trend. Weak systems aloft may bring enhanced cloud cover on some days, but rain chances are minimal.

DISCUSSION
Now through Sunday...A weak upper level disturbance passing over the region this morning will maintain high level clouds through late morning, before skies become mostly sunny this afternoon. Concerns for hazardous weather remain minimal through the next week. There is high confidence that upper-level ridging and surface high pressure will build over the Northeast Pacific, with increasing uncertainty in the amplitude and position of the upper ridge later in the forecast. Early in the period, while the ridge is centered well offshore, upper shortwaves within northwesterly flow aloft may produce increased cloud cover, but chances for rainfall remain 5% or less through the middle of the week. On clearer nights, areas of fog are most likely to develop within sheltered valleys. As the ridge axis shifts east, temperatures will trend upward through at least Thursday, reaching the 60s along the coast and upper 70s to around 80 degrees along the I-5 corridor. Later in the forecast period, uncertainty in the evolution and possible break-down of upper-level ridging introduces a similar uncertainty in forecast temperatures. Highs are most likely to continue in the 60s to mid 70s, but the spread of possible outcomes becomes wider: chances of reaching 80 degrees along the I-5 corridor are generally 15-45% Friday and Saturday, but there are also 10-25% chances of remaining below 70 degrees. The next opportunity for widespread rain holds off until late next weekend when there is greater consensus that the ridge breaks down. 36/DH

AVIATION
High pressure will maintain fair conditions with high level clouds moving overhead through the day. Northwest flow of 5-10 kt through the day with wind gusts along the coast up to 20 kt possible. Winds relax this evening and overnight. Marine stratus pushed back toward the coast this evening, mainly along the northern Oregon and southern Washington coast. Probabilities increase to 60-90% for development between 02-06z Wednesday for KAST and much lower at 20-30% for KONP. Guidance suggests stratus developing along the Columbia River toward the Portland/Vancouver Metro between 10-1z Wednesday.

KPDX AND APPROACHES...VFR conditions expected through at least 06z Tuesday. High clouds expected to clear out this afternoon.
Light northwest winds expected to increase to 8-10 kt by 22z this afternoon. Stratus pushing inland along the Columbia River could reach the metro between 10-16z Tuesday with a 30-60% chance for sub-VFR CIGs , mainly for KTTD and KPDX. -19

MARINE
Northerlies are expected to persist through much of the week as the summer-like pattern settles in. Strongest winds are expected during the afternoon and evening periods as a surface thermal trough strengthens over the southern Oregon coast. A Small Craft Advisory has been issued for the inner coastal waters south of Cape Foulweather later this afternoon into this evening for gusts up to 25 kt. Similar conditions are expected on Tuesday. Seas around 6 to 8 feet are expected through the week as well.

Small Craft Advisories are in place for the Columbia River Bar early this morning, and again early Tuesday morning, for strong ebb currents which will produce hazardous conditions to small craft. Strong ebb currents are possible during the morning hours each day this week. /DH

PQR WATCHES/WARNINGS/ADVISORIES

OR...None.

WA...None.

PZ...Small Craft Advisory from 5 AM to 9 AM PDT Tuesday for PZZ210.

Small Craft Advisory until 11 PM PDT this evening for PZZ253.