Winter Is Over In The Lowlands & Gorge

March 3, 2014

We’re into early March now and no maps/models show any real stormy weather, or cold.  In fact they look quite mild through the first two weeks of the month.  So it’s time to put a fork in winter:

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What does that mean?  This applies to anywhere west of the Cascades (including the Coast and Columbia River Gorge below 500′ or so).

1. You can take your snow tires off IF you plan to stay in the lowest elevations (below 1,500′) for the next few weeks.

2. You can unwrap your pipes, or any plants that need to be protected from temps below 25-28 degrees.

3.  We won’t see more school snow days or delays in these lowest elevations.

4.  Strong and cold east wind episodes are finished in the Gorge.  Still windy at times, but not the winter stuff.

5.  Dense widespread fog is unlikely now until October.

Here’s a good idea of what we won’t see again until next winter and what is still possible:

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Note we could still get in a pattern (like March 2012) where we get some wet snow in the morning at 32 degrees and then it’s 45 in the afternoon.  Even that is unlikely once we get past mid March.  Sure, there have been some real freak events in the past, but the chance of that occurring again in any one year is extremely slight.

And what a weird winter it was…2 months of absolutely nothing sandwiched between two arctic blasts with snow/ice.    Those two months included drought conditions with sun and fog from early December through early February.

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The only “normal” part of winter was the last 3 weeks of February!  A horrible ski season (the first 3/4) with several ski areas not opening until the early part of February and the others limping along on minimal snow through mid January.

We finally had some decent snow this winter.

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PDX had 8.0″ total, most of that during the 3 snowstorms in early February.  Of course those of you from Albany to Eugene had TWO big snow events…better than anything you’ve seen in decades.

There has been one other oddity so far this winter:   A total lack of snow in areas that typically receive far more snow than Portland.  Those areas from 1,000 to 2,500′ in the hills, foothills, and lower Cascades.  Almost every time we’ve been wet, snow levels have been 3,000′ or higher.  At my home at 1,000′, I have seen the same total as Portland and less than many other lowland locations.    When is the last time you heard us say “snow down to 1,000 to 1,500′ tonight and tomorrow”???  I think I may have said that once this winter.  It has either been mild and wet or cold with lowland snow when we have precipitation, an absence of chilly onshore flow behind fronts.  An example is at 2,600′ northwest of Mt. Hood at the South Fork Bull Run SNOTEL site.  Even at that “high” elevation, no more than 9″ of snow has been on the ground since the 16″ accumulated during the arctic blast in early February.  Highly unusual to have only a few inches on the ground at that elevation in late February or early March.  As of today there is no snow on the ground.

Chief Meteorologist Mark Nelsen


Sleet “Drifts” In the Gorge

March 3, 2014

The west end of the Columbia River Gorge saw freezing rain during this weekend’s event, but once you got around Multnomah Falls there was a transition to snow.  This is very common with cold airmasses in the Gorge…coldest east of the Cascades and thinning rapidly west of Cascade Locks.  In this transition area, the cold air in the lowest elevations wasn’t quite deep enough to keep the snowflakes together up around 2,000-3,000′ or so.  So the snowflakes melted into raindrops.  Those raindrops then fell into the cold air stuck in the Gorge; but in this case it was so deep the drops had a chance to freeze into ice pellets before they hit the ground.  This is also sometimes called sleet, although the official definition is ice pellets.  I have also heard it called “tapioca snow” by road crews in that area in the past.  First time I heard that was 22 years ago…I’m getting old.

Anyway, this was one of those times where quite a bit fell between Bridal Veil and Bonneville Dam.  In past cases I have seen it occur in the same area.   These ice pellets easy bounce, slide, and roll down steep hillsides so they will form drifts (but not from wind) in gullies and other locations.  If they are deep enough, a plow can’t handle it and ODOT has to call in a snow blower.  That happened today near Multnomah Falls:

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In 1996, when we had two back to back severe ice storms in the Gorge (2 days apart), the ice pellet drifts were massive, 10-20 feet high and blocked the old highway for many days.  There was very little snow, just ice pellets and freezing rain.  Here’s a picture of my (soon to be) wife standing in front of one…wow, 18 years ago in late December or early January that year.    This was just west of Multnomah Falls:

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She didn’t approve me using this picture, but it’s okay, she doesn’t read the blog anyway.  Shhh!  Plus I don’t have any other pictures of the drifts.

Chief Meteorologist Mark Nelsen

 

 


A Few Ice Pics

March 3, 2014

Lots of ice yesterday; here are a few pictures of just one section of the driveway.

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After the chainsaw work:

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There are a couple short videos of the trees falling on my Facebook page:  Luckily it only took me 1.5 hours to cut my way out to the road.  But part of it had to wait until 11pm last night once the ice had fallen off the trees and I wasn’t in danger of being crushed.  I ended up with about 3/4″ of ice at home.  Some folks in the Gorge are just now up to freezing; but here at the far west end it’s all gone since temps rose into the 40s around 8pm.  There are spikes of broken trees sticking up all over.  Alders tend to just break off, the trees in the pics below were black locust, they just came over roots and all. This is the most damage I’ve had in the 10 years I’ve been living in this spot. Not sure why because I’ve had thicker ice. It’s possible that we just haven’t had a heavy ice coating in several years so it was just time for some “pruning”.  Also, did you notice the mainly bare driveway?  Even at 28 degrees during the night the driveway and most pavement didn’t freeze.  I haven’t seen that before; most likely due to the warm day on Friday.

And for Jason (who comments here), whew! I got lucky, the trees just missed crashing on top of that new wellhead!

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That’s under the plastic cover.

Chief Meteorologist Mark Nelsen