Exciting Evening in Weather Center

 That was a fun 2 hours!  Two clusters of thunderstorms did indeed form as our RPM showed (see previous post from midday).  One passed from Beaverton down into Clackamas County, and another from the Coast Range out past McMinnville and Dundee.  Appears to be about 110 cloud to ground (or ground to cloud) lightning strikes within the range of this map.  It was a good weekend to work!  My co-workers are still finishing up their honeymoons.

At 11pm the showers are almost all east of I-205 and 99E, mainly in the Cascade foothills.

Chief Meteorologist Mark Nelsen

Thunderstorm Over Westside

A very heavy thunderstorm has developed right over the top of Beaverton at 8:10pm.  I can hear the rain pouring outside and my co-workers berated me for letting them keep their windows down.  Of course I put mine up just in case of this.  It’ll move slowly east-southeast towards SW Portland the next 1/2 hour.

First Thunderstorm of Day: Near Forest Grove

A nice cell just popped up out of nowhere just a couple miles west of Henry Hagg Lake at 4:45pm.  A couple cloud to ground strikes already.  We’ll be keeping an eye on it (and any others that develop) during the 5pm newscast on Fox12.

Metro Thunderstorm This Evening?

Warmest night of the year so far last night with a low of only 59.  Sure feels like a summer morning out there and I think I like it!

Lots of clouds out there this morning and we’ll only be partly cloudy today as the upper level low off the California coast spins the moisture up over us.  Assuming we get plenty of sunbreaks between the cloud cover, we should still be able to hit 80.  If it stays too solid, it might only be a 76 degree day instead.

I’m not too excited about the chance for thunderstorms later this afternoon and evening except for one spot. 

Our RPM model (the only one that shows it) has shown an interaction of a northwesterly marine push this evening and the available mid-upper-level moisture right over the Portland Metro area.  I couldn’t include the whole loop, but notice the 10pm forecast shows a cluster of showers/thunderstorms right overhead.  They form around 7-8pm on this model and hang nearby until about midnight.  There is a slow movement from NW to SE.  This is about the 6th run of our model showing the same thing; we get a new 27 hour run every 3 hours.  Now the WRF-GFS from the UW doesn’t show anything similar, so it might be some sort of convective feedback on the model.  Either that or it’s the only one implying there will be just enough lifting with the arrival of the marine air this evening to set off a few thunderstorms or showers.  Of course the fun part of weather watching/model riding will be to see what actually occurs.

Chief Meteorologist Mark Nelsen