A Wet & Windy Weekend Ahead

October 22, 2010

I’ve had a pretty good amount of time to look at the models, satellite, radar etc.. this evening since I only have 1/2 hour to do at 8, 10, and 11pm.  That’s good because there has been plenty to look at.

Here’s what I see that’s different compared to 24 hours ago.

1.  Less rain tonight:  A weakening front and (slowly) filling low pressure offshore with storm #2 are both approaching.  Not a real solid band of rain, but some “shower bands” seem more likely between now and morning.

2.  Slightly weaker wind tomorrow from storm #3, the strong one:  You can see on our RPM model that there is far less 50+ mph average windspeed approaching the coastline tomorrow evening compared to what it showed last night at this time.   Still, average surface windspeeds 40+ and 5000′ wind 70 mph can easily mix down gusts to 60+ mph, so I said 55-65 mph gusts along the coast overnight tomorrow night.  Here in the Valleys it’ll probably be windier during the day Sunday as the gradient is tightest south to north at that time.  30-40 mph gusts are likely then.

3.  Snow level not quite as low Sunday night through Monday:  Looks like it barely touches 4,000′ by Monday morning, so it may be tough to get sticking snow down to Government Camp…better chance for that Monday night and Tuesday.  If you really want to see a lot of snow, head higher, Timberline Lodge should get 10-15″ at least during the Sunday night through Tuesday period.

4.  A lot of rain here in the Valleys:  We get steady rain later tonight (just barely), then a good slug tomorrow night and early Sunday morning with the 2nd cold front.  After that it’s a steady barrage of strong westerly flow showers and waves of showers for 48 hours (through Tuesday morning).  It all adds up!  Maybe 2″ in the driest parts of the Metro area and 3-5″ in the Cascade and Coast Range foothills.  Very impressive for late October.

Overall still plenty of weather excitement this weekend:  a deep sub-960mb low moving relatively close to the Pacific Northwest, soaking rains, and a windy day or two.  Not a bad start to our La Nina “Wet Season”!

Chief Meteorologist Mark Nelsen