More Rain Tonight, but Drier Long Term

June 6, 2012

Stephanie and I had a great time down at the Junior Parade this afternoon. Thousands of kids, bands, and partly cloudy skies made for lots of fun. Luckily sprinkles stayed up in the Coast Range.

That changes quickly tonight as a juicy cold front moves inland. This is the leading edge of another cold upper-level trough. That trough will be cold enough to bring a dusting of snow to the Cascade Passes again Friday and/or Saturday mornings. 850mb temps down around -1 both mornings are very chilly for the first week or so of June.

So is this the last really cold trough?  I have doubts that it will be, but the GFS and ECMWF are now showing (in the past 24 hours) much weaker troughs for next week, with even some brief ridging around Monday-Tuesday.  If so, we’ll easily see temperatures climb back to normal or a little above.  Note the 18z GFS ensemble chart; the red line is the ensemble average, and starting Monday it is near average for the following 10 days.  Now you can also see a few ensemble members that must have cooler troughing over us, evidenced by the lines from the 12th-17th well below the average.

The 12z ECMWF is quite similar, showing near average conditions starting late Sunday and through most of next week.  Based on this, I’m finally going to plant my corn, squash, and beans.  I need to because I’ll be off on vacation and out-of-town from Saturday through the 20th.  That’ll be too late to get those warm weather veggies started; so it’s time to take the jump and plant now.  I live in a colder location so I normally have to wait to around early June anyway, so this isn’t too far behind.  I hope these models are correct in forecasting a return to more typical June temps!

By the way, if you have plans to head to the Grand Floral Parade Saturday morning, the forecast is a bit iffy right now.  We are on the backside up the cold upper trough and our RPM is sending a weak vorticity maximum down from the north that day, generating lots of cloud cover and light showers in the onshore flow.  Our current forecast only indicates a “chance of a shower”, but our model has more of a steady drizzle or light rain.  Luckily, 2 more days to refine the forecast:

Chief Meteorologist Mark Nelsen