Lots of Rain and Cold Air Still On The Way

November 15, 2011

We’ve got a huge soaking on the way Wednesday!  A very wet warm and cold frontal system is on our doorstep tonight.  This will be by far the wettest storm this Fall both in terms of rainfall and mountain snow.  I think our RPM model (above) is probably a bit wet, and notice the smoothing issue as mentioned in a previous post.  When I read this I usually take that Hillsboro number and consider it to be a metro-wide rainfall.  But 1.50-2.00″ is a real healthy rainfall.

Still looks like 18-24″ total up in the mountains that is here to stay; the result should be at least some minimal skiing this weekend on Mt. Hood.

Okay, so how are snow levels looking?  I still feel a solid 1,500′ for most areas is good, but I’m sure some spots down around 1,000′ will see at least a dusting.  Best chances for that are early Friday morning or Friday evening if a cluster of showers moves through.  Sticking snow is still looking very unlikely at the lowest elevations. 

That said, I bet at least 50% of us will see at least flakes mixed in at some point during the 18 hours Friday 5am-11pm.

A real chilly air mass, coldest so far this Fall by far, moves in late Friday and Saturday.  IF we get good clearing either Friday night or Saturday night, we’ll be way down into the 20s. 

As for that Saturday system?  Looks slightly closer on the 00z runs compared to 00z last night.  The 18z GFS was quite a bit closer to the coastline, but now it’s back to farther offshore.

This isn’t one of those situations where the cold air lingers, it’s back to southerly low-level flow by late Sunday or for sure Monday AM.

Next week looks very rainy and windy.  The 00z GFS has some deep lows close by, and the GEM (Canadian) has them even closer.  More weather action to come…

Chief Meteorologist Mark Nelsen

Briefly Dry, Then Big Cascade Snow

November 15, 2011

I’m blinded by the sun this morning…I know many of you have fog, but what a change from yesterday!  The precipitation has shifted south and we get a break until tonight.

A quick check-in since I’m headed to two schools this morning.  No new thoughts on low elevation snow Friday.  It’ll be close Friday morning, but still too warm for sticking snow in the metro area.  Then we dry out and turn chilly this weekend.  Models still keeping low pressure offshore on Saturday (fingers crossed), avoiding a possible encounter with the chilly east wind.

Check out our RPM snow total forecast for the next 72 hours!  That’s 2 ft. of new snow on Mt. Hood; almost all of it from Wednesday night through Friday morning.


Chief Meteorologist Mark Nelsen