Saturday Snow?

Monday, January 9, 2012
11:51 P.M.

Saturday...

Most snow looks to fall west of here

Guess I'd better grab a beer, and hope

To bring snow east

On Saturday

Suddenly

Euro worse than what it used to be

GFS sucks, and it bothers me

Snow some will see

But not for me

I'm a big Paul McCartney fan, and I love this song. However, I'm usually not in a good mood when I listen to it, because I'm likely coping with a loss of some sort. Maybe I dropped my ice cream on the floor. Maybe I got caught stealing from a store. Maybe I got attacked by a boar, lost my oar, and now can't get back to shore. o.O

Saturday is actually looking like it may be a decent snow event for some areas. We have a weak low pressure system moving off our coast to provide some moisture, and the air will certainly be cool enough for snow. The question is if the moisture will reach far enough west to give the Puget Sound lowlands some snow, and right now, it is forecast to just be out of our reach. Peep up this model below.

Valid 04:00 pm PST Sat, 12 Jan 2013 - 84hr Fcst - UW 12z WRF-GFS: 4km 10m wind speed, 2m temp, SLP

In the above frame, we have cool air over our area... definitely cool enough for snow. We also have a low pressure system off our coast. This is actually a super weak low pressure system; the average atmospheric pressure is 1013 mb, and this low is expected to have a minimum surface pressure of 1016 mb. But as this next picture shows, the moisture doesn't make it to the Puget Sound area.

Valid 04:00 am PST Sun, 13 Jan 2013 - 96hr Fcst - UW 12z WRF-GFS: 12km 24 hr precip, 10m winds

Seattle, Tacoma, and Everett are essentially dry from Saturday morning to Sunday morning, with just a few hundredths of precipitation expected. Meanwhile, places like Longview could get hammered. Check out the 24-hour snow totals for the same time period.

Valid 04:00 am PST Sun, 13 Jan 2013 - 96hr Fcst - UW 12z WRF-GFS: 12km 24 hr snowfall

The snow just barely misses us. Wouldn't it be great if that big band of snow traveled 50-100 miles to the east?

I don't want to get ya'lls hopes up, but there is a chance this could happen, simply because the event is 3-4 days out. A lot can change between now and then. Of course, the precipitation could move further west, meaning that the precipitation would fall over the ocean. In this case, the precipitation would probably either be rain or a rain-snow mix due to the relatively warm temperatures off the Pacific. 

In the meantime, we've got a nice convergence zone up north right now.

Valid 3:28 PM PST, Wed 9 Jan 2013

This zone has remained pretty stagnant. Right now, lowland locations in the zone are just getting a light rain, but this should change during the overnight hours. Any location between north Seattle and Bellingham has the chance of picking up 1-2 inches of snow. Most places will see little to no accumulation. If the convergence zone is pretty strong and stays in one area, higher accumulations in the 3-5 inch range could take place. The best resource for finding out if it will snow tonight is to look at the radar and see where the convergence zone is. Convergence zones are fickle and it is difficult to forecast where they will go ahead of time, so radar-watching is your best way to keep informed on the snow chance. Kids in Seattle should do their homework for school tomorrow.

I'll keep hoping something will change on Saturday. In their 3 PM forecast discussion, the National Weather Service office in Seattle had this to say about Saturday:

 ABOUT HALF THE MODELS CONTINUE TO DIG A SHORT WAVE  
  THROUGH THE AREA IN NLY FLOW WHICH COULD POTENTIALLY PRODUCE  
  WIDESPREAD 1-3 INCH AMOUNTS. THERE ARE OTHER MODELS THAT TAKE MOST  
  THE ENERGY OFFSHORE AND WOULD RESULT IN NO SNOW AT ALL OR PERHAPS  
  JUST NEAR THE COAST

Enjoy your day!
Charlie