A Very Warm Night, Then A Record High Today

April 24, 2018

9:00pm Tuesday

Today sure felt like summer didn’t it?  The strong “offshore” easterly wind didn’t let up for many of us last night; some of us in the metro area and most coastal cities didn’t even get down to their typical high temp!

Mark Coast Warm Lows

Here in Portland we dropped to 53 degrees, not quite a record warm low, but close.  Then the easterly wind pushed temperatures above 80 degrees for most of Western Oregon and parts of Southwest Washington this afternoon.

Todays Observed Highs OrWa 2017

The 88 at Roseburg was the highest observed temperature in Oregon today.  Two cities set records for the day: Portland and Astoria.

Record Highs Cities

Obviously the “scorcher” is a bit tongue-in-cheek, but these temps are far above normal for the last week of April.

I expect 3 changes (minor) for Wednesday:

A) Wind turns onshore (southwesterly) along most of the coastline = MUCH cooler.  Likely 60 around Newport to low-mid 70s up at Astoria

B) Warmer atmosphere overhead everywhere east of the Coast Range.  850mb temps at Salem were +14C from the balloon this afternoon.  That’s exactly what models showed.  They all say +16 tomorrow afternoon.  That would give us about 3 degrees warming.

C) East wind backs off.  It’s already happened the past 6 hours, but pressure gradients east to west over the Cascades will be weaker tomorrow.  We still get offshore flow, but with far less mixing, afternoon temperatures should rise a few degrees.

Combining the last two I figure we get about 5 degrees of warming in the metro area tomorrow, specifically the areas that were a little “cool” due to the wind today.

Thursday is real interesting because the east wind comes back a bit stronger, then goes almost calm late in the day as a major marine push begins to push into the central/southern Willamette Valley.  Thursday may be one of those days where we make it to 85 in Portland, Salem is 78, and Eugene only hits 70.

We have a HUGE change coming up Thursday night and Friday as we get a “double whammy”.  A major marine push (solid marine layer 5,000’+ thick west of the Cascades) plus a band of rain moving north through Western Oregon.  It’s likely we stay in the 50s Friday.

So we’ll likely go from summer-like warmth in the 80s Thursday to 50s and wet/gray all day Friday.  Pretty drastic for our climate, but I’ve seen it happen before.  Plan to have all your dry weather projects done by Thursday evening!

Chief Meteorologist Mark Nelsen