Massive Lightning Outbreak Hits The Northwest

One of the greatest Northwest lightning outbreaks in recent memory occurred today, with well over 5000 lightning strokes over the region.

Below are the strokes over the past 24 h:  very impressive.  

There were three major thunderstorm paths...one down the lowlands of western Washington, one along the coast, and a broad band in eastern Oregon and Washington.

Importantly, there were very few lightning strikes on the eastern side of the Cascades, which greatly reduced the chances of forecast fires there.

The massive lightning activity over northeast Oregon did start fires.

Normally, the Pacific Northwest is the poor stepchild of lightning activity in the U.S.  But look at the national lightning activity for the past 48 hr below.  For once, we were in the league of Florida or Texas!

The radar image this morning was enough to promote goosebumps for the meteorologically inclined:

And today's precipitation totals were quite significant, with several locations receiving over a half-inch (see today's totals below).

The visible satellite image  around 10 AM looked like something out of Oklahoma:

During the morning, several folks told me they saw funnel clouds, based on pictures like this:

I saw such clouds myself... which result from aircraft passing through a low cloud deck. NOT a tornado.

Let me end with a truly remarkable image.

Low clouds were left in the wake of the thunderstorms over western Washington, but Mount Rainier extended above the clouds. Eastern Washington is now experiencing plumes of smoke from fires ignited by the lightning over northeast Oregon. The green areas show lightning strikes.

  

 

Thunderstorms and Rain Coming to the Northwest

For most summers, during July or August there is an intrusion of "monsoon" moisture from the southwest into our region, resulting in showers and thunderstorms...and this year will be no different.

Such thunderstorms can be both good and bad.  Good at providing needed rain and lessening fire risk, but bad if lightning starts fires.

The predicted totals through Friday morning (seen below) range from a few tenths to a half inch, with higher values along the coast.

The wet fun will begin later this afternoon and evening as convection and thunderstorms build near the crest of the Cascades (see forecast for 5 PM below).

Overnight, more serious thunderstorms/convective showers will move into the region, as suggested by the forecast weather radar image at 2 AM from the University of Washington forecast system:

The latest forecast of the NOAA HRRR model is quite similar (simulated radar at 1 AM shown below).

Why this wet bounty?

Two things are occurring together.   The upper-level pattern includes an approaching upper-level trough (500 hPa, about 18,000 ft shown for tomorrow morning).  Such troughs produce upward motion (which helps initiate cumulus clouds) and bring in moisture from the south.

Such "monsoon" moisture and unstable air from the southwest are evident in the forecast below.

Total water vapor content of the atmosphere this evening.  

Blue and red are higher values

Enjoy the show overnight!