PORTLAND, Ore. (KOIN) – Saturday will start cloudy with sunshine breaking through late in the day. Portland can expect daytime high temps around the mid 70s. A weak low pressure system arrives Saturday, which means eastern and central Oregon, including the Cascades, may see isolated thunderstorms during the afternoon. 

Sunday and Monday showers may swing through the coast and Willamette Valley. These showers appear to be very light. We’re likely to be more dry than wet Sunday. Showers may linger Monday morning. Just in time for fireworks, the sky should clear Monday afternoon and evening.

Traveling this weekend? Be aware of thunderstorm threats eastern Washington, central and eastern Oregon.

Flood Watch issued by National Weather Service

FLOOD WATCH IN EFFECT FROM SATURDAY EVENING THROUGH MONDAY EVENING…

* WHAT…Flash flooding caused by excessive rainfall is possible.

* WHERE…Bonner and Boundary counties in northern Idaho. Chelan, Ferry, Okanogan, Pend Oreille, and Stevens counties in Washington.

* WHEN…From Saturday evening through Monday evening.

* IMPACTS…Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations.

* ADDITIONAL DETAILS…Several rounds of showers and thunderstorms are expected during the holiday weekend, beginning on Saturday night and continuing through most of the day Monday. The showers and storms will be rather slow-moving and capable of producing torrential downpours at times. Excessive runoff from the precipitation may result in flooding of small creeks and streams as well as on and near burn scars and in areas of steep terrain. Rock slides and mud slides will be possible.

https://forecast.weather.gov/wwamap/wwatxtget.php?cwa=OTX&wwa=flood%20watch