Frigid Temperatures, Dangerous Wind Chills, and More Snow Ahead

No FastCast tonight...keep reading below for more information on the very cold weather ahead.

Lots of winter weather impacts are ahead for the Pacific Northwest over the next few days, as a massive winter storm spreads across the country.

Note on snow: Very dry air (humidity 30-50%) will make it quite hard for snow to fall anywhere north of Tacoma and from Puget Sound eastward. Snow is possible most of the night for the Hood Canal area, accumulating 2-4". Remaining snow will freeze overnight, with icy spots possible for the morning commute.

Let's start with low temperatures. Below is the latest European model forecast for Thursday morning's lows.

Persistent cloud cover will keep temperatures mainly in the mid 20s for the lowlands, with colder lows in the low 20s possible for the foothills. Eastern Washington will be very cold, with lows in the low single digits to mid teens, with some mountainous areas dropping below zero.

Gap winds overnight will bring very cold, sometimes dangerous, wind chills through the day Thursday. Expect peak gap wind gusts of 20-30 mph in the lowlands and 40-50 mph in the foothills, mainly from North Bend to Enumclaw. Additionally, strong Fraser River outflow winds will continue gusting 30-50 mph in Whatcom and San Juan Counties, bringing dangerous wind chills and potential freezing spray on the water.

Below is the European model's forecast for wind chills at 7 AM Thursday.

At 7 AM, expect wind chills in the teens for most of Western Washington, with the coldest temperatures in the upper single digits to low teens in the foothills, Whatcom & San Juan Counties, and from Puyallup to Seattle. In Eastern Washington, morning wind chills will range from -20 to 0, with frostbite possible in under 30 minutes on exposed skin.

Next, let's take a look at wind chills by 1 PM Thursday.

It's safe to say that Thursday will not be warm. Most of the lowlands will have wind chills remaining in the 20s, with wind chills in the low 20s likely around midday for most areas. Eastern Washington will have wind chills of -10 to +20 around midday.

As you'd expect, high temperatures on Thursday will struggle to get out of the 30s. Below is the European model's forecast for highs on Thursday.

Generally, expect highs in Western Washington to be in the low to mid 30s, and in the low teens to mid 20s in Eastern Washington. Any remaining snow won't melt easily on Thursday, and any wet spots will briefly melt or remain frozen.

Once the sun sets, wind chills will drop back into the teens for Western Washington and the -20 to +10 range for Eastern Washington.

The same conditions are expected on Friday, but we will review that in the next blog. 

Confidence is increasing in a region-wide snow event from later Saturday into early Sunday. Timing and exact amounts still vary and will definitely change, but a decent possibility of a forecast is below (European model, total snow through Sunday evening.

1-3 inches is a good bet as of now for most of the lowlands, excluding areas from North Seattle to the San Juans, where the traditional "rain shadow" is now more of a snow shadow.

Remember that amounts, timing, and how much snow will stick around is all likely to change. Stay tuned, as I will have lots more updates on the continued winter weather!