Cascade Snow and Dull Maps

November 8, 2010

A great setup for a heavy snowfall in the Cascades the next 36 hours;  a cool occluded front coming in from the west-northwest and good westerly flow for 12+ hours to ram the moisture right into the Cascades.  The combo of frontal precipitation an heavy post-frontal convective swaths of heavy showers should give the mountains 6-10″ of new snow.  It will suddenly cut off after midnight tomorrow night, but this will be the first time we see snow down in the 2,500-3,000′ elevation this season.

Unfortunately that’s about it for the Ski Areas the next 7+ days.  A few more inches MAYBE late Thursday, then a warmer system over the weekend will probably give a rain/snow mix or just rain.  Timberline will re-open Pucci Wednesday (I’m ignoring that little Bruno lift), and Meadows could see a base up around 20″ or so even at the lodge by Wednesday morning.  But with little to no snow during the following 7 days, it’ll be tough to really get the ski season going.  I don’t see any warm and rainy systems for substantial melting, and the mid-November sun isn’t very good for melting a lot of snow.  So most likely what we get on the ground now will stay in place.  But looking at the long range, it appears unlikely we’ll see a widespread ski-area opening with decent conditions before at least the weekend of the 20th-21st.

What’s the problem?  Exactly what I mentioned last week.  In general a large ridge of high pressure in the upper atmosphere will build just to our west during the period, meaning we just get weak systems that come down the front side of the ridge.  Precipitation should stay on the light side.  No real juicy Pacific storms.  Models have been very consistent showing the ridge axis centered around 140W.  That’s close enough to keep the cold arctic air to our north and east, but not close enough to give us lots of fog and a serious inversion (yet!).    The image above is one I’ve shown before; the 6-10 500 millibar height anomaly from CPC.  You can see the ridge and then a cold trough centered over the middle of the USA.

In the short term…what a cold and rainy day coming up tomorrow.  Rain arrives right around daybreak, then changes to more showery weather later.  A round of hail or a rumble of thunder is definitely possible with the lifted index down around zero.

In case you have nothing else to do, I’ve posted pics of my 3 month long project to build a chicken coop and fort for my kids on my “Mark Nelsen” Facebook page.  It’s also on a web page here:

Chief Meteorologist Mark Nelsen