LONG BEACH — Heavy rain is expected to spread into Southwest Washington and Northwest Oregon Sunday and continue Sunday night into Monday.
The heavy rain is expected to develop as a result of a feed of tropical moisture out around 150W longitude that was forecast to begin reaching the Pacific Northwest late Saturday night but hit the region in earnest Sunday afternoon and continue Sunday night through Monday morning.
Model projections show 3 to 5 inches of rain Sunday and Monday for the south Washington coast, the Willapa Hills, the south Washington Cascades, the north part of the north Oregon coast and Coast Range, and the north part of the north Oregon Cascades such as around Mount Hood.
Current river model forecasts indicate that area rivers will rise sharply but stay below flood stage. One exception could be the Grays River around Rosburg in Western Wahkiakum County. Forecast rainfall amounts are enough that it could rise to near flood stage Sunday night or Monday morning. The lower Cowlitz River around Kelso may also approach bank-full levels by Monday.