Record Warm March

March 30, 2015

Can you believe 5 of the past 12 months we’ve seen all-time record warm conditions in Portland?  Yep, August, September, October, February, & now March are the warmest in Portland Airport history:

MarkTempDeviation_PastYear2

There are two reasons.  For one, there has been a tendency for upper-level ridging to hang around the West Coast or eastern Pacific for much of the past two years.  The other is the unusually warm eastern Pacific ocean waters, also called “The Blob” over the past 18 months or so.  You can see it on the sea surface temperature anomaly map:

sst_anom

One of the results of all the warm weather is the growing season running well ahead of schedule.  My apple trees are beginning to bloom; these typically bloom a month from now.  Chris Markes was out in the Hood River Valley today and says it is already at the peak…a good three weeks ahead of the main blossom festival time.  So get out there within the next week!

chrismarkes_blossoms

There have been several periods over the past year where the ridge has broken down and we return to a wet & cool weather pattern for a week or two, or three.  This is happening again for at least the first couple weeks of April.  Between now and April 15th there will likely be more snow above 5,000′ than we have seen since December!  Lots of showers in the valleys too.  Let’s just hope for no frost to ruin the blooming trees.

Chief Meteorologist Mark Nelsen

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