Surprise

Were you awakened last night about midnight?  No.  Too bad, you missed a rare occurrence around these parts.  Yep, we had a thunderstorm.  Unfortunately I slept through most of it (dang it), but I did catch the tail end.  It’s interesting to note that thunderstorms are fairly uncommon around here to begin with, but to have a night time storm is even more interesting.  See, normally around here it’s the daytime heating of the lower atmosphere that causes the lifting mechanism to create storms.  Last night, the conditions that setup were pretty interesting.  Here’s the discussion at the NWS:

“…THE CURRENT UPPER LOW JUST OFF THE WA COAST AT 09Z WILL SWING NE…CROSSING THE BC BORDER AROUND 18Z. THE SHARP CIRCULATION AROUND THE LOW CREATED UPLIFT WITH DIFFLUENT FLOW ALOFT OVERNIGHT…FOR BANDS OF SHOWERS AND TSTMS ACROSS NORTHERN ZONES…”

What this means is that a low off the coast spun a piece of energy across northern Oregon.  The energy provided the lifting mechanism, as well, the diffluent flow triggered the band of thunderstorms that ran through the metro area around midnight.

Quite a surprise actually. The only indication yesterday that would have suggested T-storms were the altocumulus castellanus.  However, I still wouldn’t have expected what we got last night.  But, I’m not disappointed at all.