Wednesday: Warmest Day So Far Ahead

March 11, 2014

Today was a wonderful early spring day with temperatures up around 60 degrees in the metro area and sunshine most of the day.  Sure, a real chill in the air this morning but a comfortable afternoon.  We hit 59 in Portland.

Now all signs point to a very warm day Wednesday.

1. The atmosphere overhead warms quite a bit

2. Weak low-level flow turns easterly for the first half of the day; it will be a breezy morning in the western Gorge and eastern edge of the metro area

3. That easterly flow will mix drier air down into the lower elevations and also warm the lowest elevations.

My chart I use for the month of March shows a high temp at PDX between 65-69 degrees tomorrow afternoon.  Our RPM model goes with a high of 70 tomorrow, the WRF-GFS around 66-68.  My 10pm forecast will be 66.  We’ll see how that turns out.  We might have a decent variation around town with warmest temps near the mouth of the Gorge.  I think Troutdale could touch 70, or Hillsboro could be close…we’ll see.  So enjoy Wednesday!

It sure won’t be like 2005 though; remember that year?  We had a long stretch of record warm & dry weather from late February into mid March.

MarkHeatwaveStudio_March2005

 

The first 11 days of the month are running above average; a bit of a change from a chilly February and chilly winter overall.  Signs point to the above-average temperatures continuing for at least another 5-7 days.  What happens beyond that is a little uncertain.  Although it appears to me we are probably headed for cooler than average temps as we head toward Oregon’s spring break.  That’s the last week of the month.

Last night at 10pm I mentioned the disparity in snowfall totals vs. elevation this winter.  In fact two rainstorms and mild weather in between have only made that more noticeable.  Take a look at two locations.  The first is just below Timberline Lodge.  The other is west of Kingsley Reservoir near Mt. Defiance (west of Hood River).  The bars represent February 10th and March 10th % of average snowpack.  Notice higher elevations improved a little, in fact above 5,000′ snowpack is only slightly below average on Mt. Hood. Yet it is abysmal below; down to 35% of average at 3,000′.  Basically there is very little snow below the 4,000′  elevation.  This highlights what I mentioned in my winter wrapup; that we’ve seen very little 1,000-3,000′ snowfall this winter.  And the warm temps the last 3 weeks (above the cold Gorge influence) has actually started the normal melt a little early.  March could have been the big “make up” month, but it isn’t this year.  Even SkiBowl at 4,000′ only has 2.5′ on the ground, and in a normal year the snowpack starts to decrease just a couple of weeks from now.

MarkSnowpackChange_2Sites

Here is the snow depth the past few winters at 3,000′ just a few miles SE of Larch Mountain (OR):

MarkSnowpackChange_2Sites2

No better than the El Nino winter of 2009-2010 at that location, at least for mid-March.

As I mentioned, it does appear we’ll have cooler weather coming up in 7-10 days, but not sure it’ll be a decent snow-producing pattern.

Chief Meteorologist Mark Nelsen