Big Marine Push

July 11, 2007

Photo2First, the picture…lots of butterflies making a goopy mess of skiers up on Mt. Hood.  Apparently this happens sometimes in the summer when swarms of those little bugs fly over the mountain.
Now back to the weather.
Quite a dramatic marine push this evening.  I haven’t seen a "classic" southwest marine push in quite a long time.  Usually the southwest wind comes in through the "Van Duzer Gap" and the northwest wind comes in up the Columbia, so PDX gets a gusty northwest wind.  Instead PDX still has a gusty south or southwest wind.  This can be explained by looking at some Coast Range observations.  The marine air along the coast is now 3,000′ or deeper.  Last night Mt. Hebo at 3,100′ was 79 degrees.  Tonight it is 56 with southwest wind gusting close to 40 mph at 10pm.  That depth of marine air can easily surge into the Valley (and it has!).  So instead of 96 tomorrow, I’ll go for 88.  We might only be 85.  Either way the brief heatwave is over.
The lightning strikes around 6-7pm north of Crater Lake were incredible.  I saw almost one every 2-3 seconds coming in our display.  That cluster of storms is now pushing offshore of Florence.  At 11pm a new storm has developed just southwest of Eugene and is headed out to Florence.  Looks like storms will probably stay in west-central Oregon tonight, instead of moving up into northwest Oregon.  Of course all of us weather geeks know that ESE upper-level flow can give us a thunderstorm at just about any time.  I think our last threat for storms will be tomorrow night.  By Friday the upper-level flow goes more south-southwest, which may keep any storms over and east of the Cascades.
A sharp upper-level trough should give us another big marine push Saturday night, making Sunday feel a bit more like June.
As for next week, models are a bit variable, but the general theme is a trough over or just west of the West Coast.  Of course location is everything and a trough slightly offshore would be warmer and dry.  A trough directly overhead could give us cool, June-ish showers.  Mark