Numerous thunderstorms, some severe, have hit eastern Oregon and Washington over the past day…..and there are severe thunderstorm warnings between Wenatchee and Spokane as I write this blog (see sidebar). below).
The latest radar images over eastern Washington show strong storm cells, with red indicating significant radar reflectivity. Such high levels are very heavy rain or hail.
Earlier today (around 3:30 p.m.) similar strong storms were moving east across southeast Oregon (see below)
Rainfall over the past day was significant in southeast Oregon (up to 1.23 inches), and northeast Washington also experienced some thunderstorms (see below).
This is our region’s first major lighting event of the year. Yesterday (Saturday), there were a significant number of lightning strikes in eastern Oregon (see below).
The latest lightning strike map (at 7:50 p.m. Sunday) shows multiple flashes, with areas of thunderstorms in eastern Washington and other areas in southeast Oregon.
And here’s a general look at Sunday’s lightning strike. Southeast Oregon and downstream are covered in lightning, with quite a bit of lightning in NE Washington.
So why is there so much lightning?
An upper-level trough moved through today, as shown on the weather map at a pressure of about 18,000 ft (500 hPa) this morning at 8 a.m. (red dashed line shows trough path). In front (east) of the trough there is both upward movement and movement of warm, moist air from the South, both of which are very favorable for the formation of thunderstorms.
The atmosphere over eastern Washington and Oregon has a lot of CAPE (Convection Potential Energy)… think of this as fuel for thunderstorms.
To illustrate, here is the CAPE forecast at 8pm tonight (Sunday). Some values reach as high as 600 (J/kg). It’s pretty good around here, which is good news for those in the Midwest.
All of our localized thunderstorm activity will end overnight as the trough moves inland and cooler maritime air moves into the area.
