Final Chance of Snow on Sunday, Chilly Weather Remains

No FastCast today (will be included Tuesday), but continue reading the full blog below.

After a somewhat badly-forecasted and dynamic system from late Friday to early Saturday, there is one more chance of snow on Sunday.

The same system from Saturday will move back north, bringing a band of snow that will extend north to anywhere from Olympia to Seattle. The best chance of snow north of Centralia will be from midmorning Sunday through late afternoon. With temperatures in the low 30s, accumulating snow is possible, so let’s take a look at the forecast

Let’s start with the European model forecast for snow through late Sunday.

The European model shows 0.5-1 inch of snow from Seattle southward. Areas from Portland to Grand Mound will get 1-3 inches. 1-4 inches will fall in Eastern Washington and Eastern Oregon, plus 4-8 inches in the Columbia River Gorge.

Now, let’s take a look at the high-resolution NAM model, also showing snow through late Sunday.

The NAM forecast shows 0.5-2 inches of snow from Everett southward, with 2-4 inches from Vancouver (WA) to South Tacoma. Parts of Eastern Washington will receive 0.5-4 inches of snow, with 4-8 inches in the Columbia River Gorge.

Finally, let’s take a look at the high-resolution UW model.

The UW forecast shows snow stopping at Centralia, with 0.5-1 inch south of there,  plus 1-4 inches in the Cascades from Stevens Pass southward. There is also a chance of 0.5-2 inches on the Northern Olympic Peninsula, according to this forecast.

Overall, it’s a wait-and-see situation, with the main question being how far north the snow will get, and if a relatively weak system can win the battle against northerly winds. 

This will be the final chance of lowland snow in this pattern, but the weather will remain chilly, as seen in the European model’s forecast for highs on Monday.

Monday’s highs will be chilly, with the lowlands not getting above 40 degrees, topping out in the upper 30s. Eastern Washington will be much colder, with very cold highs in the mid to upper 20s, except in the 30s in the lower Columbia Basin.

Now, let’s take a look at the NWS Climate Prediction Center’s extended outlooks for December 9th-13th. First up is the temperature outlook.

This outlook shows a 40-60% probability of below average temperatures into the middle of December.

Next, the precipitation probability outlook, seen below.

This outlook calls for a 40-60% probability of above average precipitation through mid December. 

In short, after a chance of snow on Sunday, chilly weather will remain, and it is likely that the pattern will turn active in the middle to end of the upcoming week, so stay tuned!