Cool Start to April, plus ECMWF Weekly Maps

April 16, 2015

I’ve been a bit lazy posting the last week or so…partly busy, but also less inspired during the warmer half of the year.

Our upper-level ridge that has dominated the weather quite a bit over the past year or so has been taking a break.  Check out the first two weeks of April compared to February.  APRIL VS FEB In Astoria, Salem, & Eugene it has been COLDER than the same period in February!  That’s quite a change in the general weather pattern for us.   For the first time since November we’ve had a two week spell of chilly weather.

In spite of the current and forecast warm weather we are in, the ECMWF model doesn’t show strong ridging coming back.  That said, the flow may be splitting quite a bit over the next few weeks.  We can see that on the 1-2 week maps and also last night’s run of the ECMWF out to one month.

Here are Weeks 1 & 2:

500za_week1_bg_NA

500za_week2_bg_NA

Cool troughs want to split off and head to our south far more often than we would typically see in late April.   You can see that in the below normal heights over the southern half of the West Coast.

Then Week 3:

500za_week3_bg_NA

About average heights over us.

Week 4 shows nothing of interest…about average:

500za_week4_bg_NA

Chief Meteorologist Mark Nelsen