We’re used to seeing before and after pictures on beauty makeover shows and in weight loss ads.  Today, I have a weather related before and after shot of the storm hitting Western Washington this morning. 

The large image was taken around 8:30 a.m., showing the classic comma shape; a sign that this low pressure system is reaching its mature stage.  Rewind just 12 hours earlier to the satellite image below.  You can see a cluster of clouds off the Oregon coast.  If you look closely, you can start to see the head of the comma shaped storm taking shape.  In a matter of 12 hours this storm literally exploded off the coast.  This rapid transformation is called cyclogenesis.  The area of low pressure deepened and the storm gained strength

Gusty Wind, Heavy Rain, and Mountain Snow   

Wind blows from high pressure to low pressure.  With this powerful low spinning northwest of the Washington Coast, a strong south-southwesterly wind is blowing across Western Washington this morning.  Some of the strongest winds have been along the coast and north of Everett with 45 to 60 mph gusts through many areas.   Sitting at 5,151 feet over the Olympic Mountains, Hurricane Ridge is living up to its name.  A hurricane force wind gust of 87 mph was recorded earlier this morning. 

As this low tracks farther north into British Columbia, winds will be easing up for the afternoon.  Heavy rain has been falling along the coast, over Whidbey Island, and around Snohomish County.  Rain will continue this afternoon and evening with the steadiest rain for Seattle during the second half of the day.  High temperatures are running in the mid 40s; well below the average high of 53 degrees for this time of year. 

If you’re traveling the mountain passes today, plan on tough driving conditions with possible delays for avalanche control.  A Winter Storm Warning is in effect through 4 p.m. today with 8 to 18 inches of new snow forecast over the Cascades. 

Colder air wraps in behind this system, dropping the snow level later tonight into Tuesday morning.  After the sun goes down tonight, some areas will be seeing snow mix in with some of the heavy showers around the sound.  High hills may see slushy accumulation through Tuesday morning.  We’ll turn over to scattered rain showers tomorrow afternoon with highs in the mid 40s.  It will stay wet and breezy through the remainder of the workweek with more rain Wednesday through Friday.  High temperatures rebound back into the low 50s. 

-Sam Argier, Morning Meteorologist