Greetings!  What a week it has been.  I’m not going to delve into the COVID-19 pandemic here; you’ve probably heard enough by now that you’re canceling plans left and right, and preparing to isolate for a couple months.

Moving on…I’ve been joking the past couple days, that some weather gods must have caught the coronavirus.  We’re just finishing up one of the most unusual patterns possible for mid-March:  lowland snow and cold east wind out of the Columbia River Gorge.  Three weeks ago it looked obvious that winter was over and done with.  I think I remember mentioning that we might see a chilly upper level trough in the first 10 days of March, that could potentially bring snow levels down to 1,000 feet and possibly even give us a few soggy flakes in the lowlands. But it was unlikely to amount to much more than that.

Instead, the totally unexpected happened:  a massive “wishcasting event” popped up on the long-range GFS maps a little over a week ago.  Obviously it didn’t get as cold as the coldest runs showed.  Friday was the first day of action.  We were in chilly onshore flow from the northwest that day; exactly like the normal chilly March trough.  But snow levels came lower than expected that day, and the snow came in the middle of the day!  Tons of flakes across the city of Portland with up to an inch accumulation above 500 feet.  Then late Friday night cold easterly flow arrived just as a fairly heavy band of precipitation was moving in.  That turned us over to all snow, and some parts of the Metro area got up to 2 inches.

Then Saturday we had another midday snow event, and this time it stuck in my neighborhood.  Roughly 1″ at the Gateway shopping center where I was working the massive crowd.  The airport officially reported 0.5″ from the two snow showers, making March 14 the only sticking snow day of the “greater” 2019-20 winter season.  I don’t think Portland has ever seen its first measurable snowfall this late before.  Saturday’s high of 42 was also a new record cold high for the date at PDX, beating 2012’s record by one degree.

The cold east wind got colder and stronger Saturday night through the day Sunday.  The high at PDX today recovered to 46 thanks to the powerful March sunshine, though wind chills made it feel more like 30-35 degrees.  I actually spent much of the day in the central and eastern Gorge, including a walk at the iconic Catherine Creek.

Afterward I took a short drive up the Centerville highway behind Lyle, up to an elevation of approximately 1,000 feet.  Lots more snow up there, and light snow began falling again during the middle of the drive!

By the way…temperatures in the low elevations of the eastern Gorge were in the mid/upper 30s today.  The Dalles had a high temp of only 37, a full 20 degrees below normal!  It’s also the 2nd latest 37-or-colder day in DLS airport history.  There was a high of 34 in late March of 1965, which is truly unprecedented.  There were also a couple nights in the upper teens in the 3rd week of the month that year, though high temps were in the 40s/low 50s.  Clearly, some sort of dry Canadian airmass slipped in to the Basin and Gorge in March 1965; even if it wasn’t quite arctic.

Today’s airmass over the eastern Gorge was arctic, at least marginally speaking.  850mb temps were around -11 Celsius.

After a cold night tonight, winter really IS over for the season.  We rebound into the upper 50s tomorrow and low 60s on Tuesday in Portland, thanks to decreasing east wind and a warming airmass overhead.  Which, after these last 3 days, is going to feel exceptionally nice under the bright sun.

Enjoy the spring weather- away from large crowds,  that is! -Karl