The forecast and weather the past almost 3 weeks has been incredibly stable.  I’ve personally enjoyed the sunny weather, but it’s all coming to an end.  Lots going on and much to cover, so let’s dive in!

Super short version

We have a rainy and breezy day for Friday. Saturday will be chilly with sunbreaks and showers. Sunday – Wednesday we maintain a shower and sunbreak pattern, but temperatures will be cold enough that snow could accumulate anywhere in the valley, and at times even along the coast. Accumulations are most likely between 6pm to 10am (during the nighttime and early morning hours). By the time we get to Tuesday and Wednesday, temperatures might be cold enough for snow to stick at anytime of the day. No major snow storms are currently being forecasted, but with cold air moving in and storms close by, things could easily change…

Details

Friday:  Rain and wind will greet us as we head out our doors Friday morning.  Classic northwest stormy weather.  Rainfall could be rather heavy at times, and winds will generally gust in the 20 to 30mph range, so not too wild.  Expect sunbreaks later in the day.  Cooler air begins to move in and our temperatures start dropping.

Saturday:  Showers and sunbreaks.  Accumulating snow should stay in the Coast Range and Cascade Range during this day. This estimated radar image actually portrays my thoughts very well. Notice blue (snow) staying in the our mountain ranges, and also notice the showery nature of the precip with some areas getting very little action.

In general, this type of scattered shower pattern is what we can expect through next Wednesday with the biggest difference being the gradual arrival of colder temps as time goes on.

Sunday & Monday:  Showers and sunbreaks.  Accumulating snow will be limited to the nighttime and morning hours, and only some of us will see snow due to the scattered nature of the showers. Because of those factors, there really is no way to pinpoint exactly who will score snow in this type of pattern. Afternoon temperatures rise to around 40 degrees each day.  Throw in a few sunbreaks and road conditions during the daytime hours should be good for normal activities here in the valley.

If this was regular shower pattern then nobody would notice if they got a few hundredths of an inch of rain versus a third of an inch. In this case it makes a huge difference between a few harmless flakes or a blanket of 3 inches of snow.

Tuesday & Wednesday:  Similar to Sunday and Monday except we will have a slightly colder airmass these days which means a heavy snow shower could briefly cover all surfaces (including roads) even during the middle of the day. Highs in the upper 30s and lows around 29/30°. For now I’m going with nothing to 2 inches of snow each night, and up to an inch possible during the daytime hours.

Thursday – Saturday:  A wide range of solutions are out there, but I can tell you with a fair amount of confidence that we stay cold with additional snow chances very much on the table. In fact, there are strong signals we stay in a colder pattern for the foreseeable future beyond next weekend.  Winter is making it’s comeback!

Hazards

Icy streets. Due to the widely scattered nature of the showers we are expecting, skies will have better chances at clearing out each night. This means icy streets for your neighborhood – even if you don’t get snow. Frozen water leftover from showers can cause just as many issues. As the week goes on and temperatures cool off even more, I expect road issues to last longer into the daytime hours. Just be extra careful on those paved surfaces in the coming days.

Things I’m watching for:

An increase in moisture would equal significant snow totals. This is totally in the realm of possibility with this specific setup. The chart below shows some hefty snowfall totals (legit snowstorms) mixed in there for Salem. At the moment such outcomes are in the minority, but things can change quickly.

On the other hand, should moisture trend to the drier side (also unlikely, but possible), then this time frame could end up being rather uneventful.

My best guess

Expect scattered snow accumulations of nothing to 2 inches both Sunday and Monday mornings with lows around 32 and highs around 40°. Remember, some of us will probably end up with nothing.

More widespread snow accumulations of 1 to 4 inches are possible on Tuesday and Wednesday. Still not guaranteed due to the showery nature of the pattern, but odds increase thanks to the colder temperatures. Highs in upper 30s. Lows 28 to 30°.

The mountains will of course see tons of snow. 2 to 3 feet of new snow between now and next Thursday for the Cascades, and at least several inches up in the Coast Range. Be prepared for snowy roads whether you are traveling east or west of the valley.

Stay safe and happy Friday! I’m sure I’ll have additional updates as often as time allows!

It’s been a very rainy, and at times, windy week. The wind event Christmas night pretty much met expectations with most valley locations recording gusts between 45 and 50mph, and some locations reaching the 55mph mark. At the peak of the storm about 30,000 PGE customers were without power in Marion County.

Rainfall has also been fairly consistent and even heavy at times. Here are rainfall totals for the past 7 days.

Generally 3 to 4 inches in the Willamette Valley upwards of 7 to 12 inches of precipitation in both the Coast and Cascade Ranges. Ignore the locations showing no rainfall. Sure, there’s a rain shadow effect, but it’s not that severe. Technical issues are to blame for those spots.

Salem can expect an additional inch of rain now through Sunday. All this rain is adding up and taking a toll on local rivers. Below is a chart showing both observed and forecasted river heights for the Willamette River in Salem.

The Willamette is definitely running full, but it is forecasted to stop just short of causing any major issues or extensive road closures.

The Forecast

Steady rain returns overnight and lasts through Sunday morning. Sunday afternoon will feature showers and downpours with a few sunbreaks mixed in. Winds will once again turn quite strong during the day tomorrow. Gusts 30 to 40mph are possible late Sunday morning and Sunday afternoon.

Snow will be heavy up in the Cascades with 12 to 18 inches of new snow falling above 4000′ tonight through Sunday night.

Monday: More sunbreaks, but scattered showers and downpours will show up from time to time.

Tue & Wed: Tuesday will be dry. Fog is likely Tuesday morning especially, but we should manage some decent sunbreaks during the afternoon. Rain moves in late Tuesday night right around midnight. So there are no guarantees your midnight street runs and fireworks will be completely dry. 😉

Thu – Sun: The rest of the week appears to stay on the wet side with periods of rain and frequent showers.

The rain Sunday could cause a few additional problems for some of you, but once we get through Sunday the threat for flooding will subside for the time being. There are no wind storms on the horizon either. Just regular Oregon rain as we ring in the new year.

Stay safe and enjoy the rest of your weekend!