Milwaukie, OR Weather

Long Term

Tuesday Night through Sunday...Another, broader closed upper low and its associated surface low will drop south from the Gulf of Alaska over Vancouver Island and into the Pacific Northwest Tuesday night into Wednesday morning. This will bring another round of cool temperatures and precipitation for the region through Friday. Even cooler air within the upper low will see seasonable temperatures continue, or even fall by a degree or two from earlier in the week. 850 mb temperatures look to drop towards 0C to -2 C, which will result in snow levels falling towards 3500 ft by Thursday morning. This is resulting in a 45-70% chance for another inch or more of snow at area Cascade Passes from Wednesday morning through Thursday night. At lower elevations, another 0.50-1.00 inches of rain may fall during this time. While the forecast trends drier as the upper low fills by this Saturday, it may still remain close enough to the region to support lingering rain showers for Halloween trick-or-treaters. At this point, there are 10-20% chances for light rain while temperatures fall through the 40s Saturday afternoon and evening, with higher confidence in dry weather by Sunday.

Now is the perfect time to check on any winter weather equipment and emergency supplies for your household and vehicles. /42-36

Aviation

Through 18Z Tuesday...An upper-level low pressure system continues to facilitate ample shower activity across the region late this morning with a mix of MVFR to VFR conditions. Going through the rest of the day, the former (MVFR) will be the predominant flight category at most sites over the next 24 hours although should a heavier shower push overhead, VIS could briefly dip to IFR (5-15% chance any given hour). Breaks between showers have a decent chance for CIGs/VIS to improve to VFR. Then starting around 23z-03z shower activity rapidly diminishes with a lull through the evening hours before another round of shower activity increases again west to east ~07-12z, persisting Tuesday morning. Winds generally remain south to southwesterly at 5-12 knots - expect gusts up to 20-25 knots at KONP until 00-01z.

KPDX AND APPROACHES...Showers continue through the afternoon hours with a mix of VFR to occasionally MVFR conditions. A period of drier/calmer weather is anticipated this evening into the overnight hours before another wave of showers arrives around 10-12z. Very high confidence (80%) in MVFR conditions from this point through the rest of Tuesday morning. -99

Marine

A slow-moving and steadily weakening area of low pressure will traverse waters through early this morning as it continues to slowly moving onshore through tonight. As this low pushes eastward, the currently southerly winds will slowly develop into a more north/northwest pattern as the day progresses, yielding widespread northwesterly flow by late tonight. Winds and seas will continue to ease through tonight as the low weakens and moves inland. Winds are expected to fall below 15 kt by this morning with seas of 5 to 7 ft.

A northwesterly swell begins to build late Tuesday into Wednesday as another system approaches from the Gulf of Alaska. There continues to be 5-20% chance for seas to reach or exceed 10 ft at any point Wednesday in the waters beyond 10 NM. For Thursday and beyond, winds are favored to ease below 10 kt while seas fall to 5 ft or less, with these conditions expected to persist into next weekend. /42

Pqr Watches

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