Sunday Morning: Stormy 36 Hours Ahead!

November 18, 2012

8:30am Sunday…

Everything still appears to be on track for a VERY wet 3 days ahead…and maybe more.  Here are the highlights for those not interested in too much detail

  • Rain picks up the rest of the day, and turns heavy at times through Monday afternoon in the core of our viewing area west of the Cascades (Longview-Salem and Long Beach to Newport)
  • Flooding appears most likely on the North Coast rivers, but as always, it totally depends on exactly where the heaviest rain sets up
  • Since rivers are starting pretty low, we’ll PROBABLY avoid a major, widespread flood, just barely…
  • Strong wind arrives at the coast this afternoon/evening and continues through the morning Monday before relaxing quite a bit
  • Peak gusts 80+ mph likely out there, a pretty good windstorm even by “storm season” standards
  • Peak gusts 40-50 mph here in the Valley late tonight through midday Monday, could be strongest on the west side of the Valley, we’ll see.  Strong enough for some power outages and a few trees down.  This isn’t a significant windstorm here in the Valley, but enough to get everyone’s attention!
  • Cascades pick up more snow through this evening, but then all rain for about 24 hours following should erase just about all of the 10-15″ that will have fallen by then.

RAINFALL

Take a look at the 72 hour rain forecast from now through Wednesday morning off our RPM model:

Right around 10″ in the wettest parts of the Coast and Cascade Ranges from SW Washington down through SW Oregon.  The other local mesoscale model, the WRF-GFS, is similar.   Here is it’s 24 hour forecast from 4pm this afternoon to 4pm tomorrow afternoon…A solid 2-4″ in the Valleys with 5″+ up in the Cascades!

The heavy rain will be covering a large geographic area, heaviest the next 24 hours in SW Washington, then heaviest the following 24 hours south of a Newport to Salem line as the “firehose” of moisture slips a bit farther south.   Once the whole front shifts farther south later Monday, we’ll see the rain taper off quite a bit, but still very wet through Wednesday.

WIND

Looks quite impressive for a big storm at the Coast.  Models sure don’t handle little low pressure areas tracking along the front very well, so it’s safer to just say that the entire wind field overhead is very strong from this evening through midday tomorrow when the front shifts farther south.  I’ve been surprised at how strong the wind is just above the surface late tonight and tomorrow morning on the models; 70kts at 850mb over the North Willamette Valley.  The orientation of the isobars is definitely not the best if you’re looking for a big windstorm, and that orientation seems to often lead to strongest southerly winds on the WEST side of the Valley closer to the Coast Range.  In the December 2007 event (much strong than this one!) the wind blew strongest over in the west metro.  Regardless, the Monday morning commute looks particularly nasty with rain blowing sideways.  Once the front shifts south of us in the late afternoon, the wind should calm suddenly.  The new 12z WRF-GFS is a bit faster pushing the strong wind south of us soon after 10am.

CASCADE SNOW

8-10″ fell up at Timberline and Meadows since yesterday afternoon, and about that much could fall again before it rises above freezing up there this evening.  From late this evening to Monday evening, 4-6″ of rain will fall in those spots!  Yuck, but hey, it’ll make for a real nice hard base won’t it?  Then it’s on to a bit more snow Tuesday and maybe Wednesday.  If so, maybe a Friday opening???  Maybe.  I see Timberline has the Pucci running today, and little Bruno too.  Gotta love their attitude!

By the way, during stormy weather, when we’re not on TV, we post updates here of course.  And we’re on Facebook (with more frequent updates) as “fox12weather”.  Same on Twitter.

Chief Meteorologist Mark Nelsen

 


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