Weather forecast for Portland, Willamette Valley March 14, 2022
Details for Monday, March 14, 2022
PORTLAND, Oregon (KOIN) – When you see the word Atmospheric River (AR), you know we have buckets of water coming our way. Before the steady rain arrives Monday night, we’ll start the day slowly in Portland.
The morning will be more cloudy than rainy, especially towards the south. Multnomah County will be right on the fringes of this first initial surge of humidity.
There is no doubt that the northwest coast of Oregon will be wet in the morning. It will take some time for a front to settle in which is expected to cross the valley on Monday evening. A window from about 5 p.m. to midnight will be really humid. This is when we will catch most of the AR rain.
You’ll want to scan the graphs below to get an idea of where the rain is relative to the dry line.
Temperatures will not be so hot with this event, as it is a weak atmospheric river. The duration of the event will be shorter and the moisture transport is not as deep. Expect temperatures in the mid to high 40s Monday morning, warming up to the mid 50s in the afternoon.
The day planner shows a chance for showers all day, but they won’t be consistent until late. Precipitable water shows this extent of moisture all the way south to the skies just north of Hawaii. This event will be primarily beneficial and non-disruptive.
Weather models project a half inch of rain from midnight to midnight Monday. It doesn’t look like an atmospheric river, but it will carry a lot of moisture. The timing of rain may actually lean toward Tuesday, splitting the rain total for the day. Between Monday and Tuesday we will have half an inch to an inch of rain in the valley. Again, not a strong AR like we had earlier in the year, but a weak AR that won’t carry the intensity or duration like the ones before.
Humidity will impact central and eastern Oregon later in the day. The day planner is set for 5pm on Monday indicating dry weather for Madras and Pendleton. Temperatures warm up to the mid upper 50s for you.