Ready to Rumble?

 The weather this past week has been rather repetitive.  Warm/hot days, cool nights, and afternoon mountain thunderstorms.  For the most part, these storms remain over the mountains, and if they try to drift off to the valleys, they die off quickly, but possibly bringing a sprinkle or light shower to the valley before they dissipate.  Here's what they looked like on radar yesterday (Friday) afternoon.


This pattern will continue for this weekend, with a change coming on Monday.  And it's kind of interesting how this change will come about.  Back on Thursday, there was a big ridge of high pressure in the Gulf of Alaska.  But there were also 3 minor little waves to monitor.  One was up in the Yukon, one off the WA/OR coast, and one out towards Hawaii.


By Saturday afternoon, the Yukon wave will have dropped southward, to just off the BC coast.  Meanwhile the other two lows will be merging off the West Coast. 


These waves will merge again as they push onshore as a fairly respectable weather system by Monday.  There's a fourth wave off to the west that will move through our area on Tuesday.


Our hot weekend will destabilize the atmosphere, and when this weather system reaches that unstable air, thunderstorms will be the result on Monday.

Sunday will see some high clouds moving by overhead, but that will just be the precursor of the event.  The wave will start to move onshore Sunday night, creating the potential for some high-based nocturnal thunderstorms across the region.  These storms usually don't produce much rain, but occasionally one or two will have a small but heavier core of rain.

Here's what one computer model thinks the radar will look like at 5am Monday morning.  Remember, this is just one computer's forecast, not necessarily what is going to happen.



By 10am, those morning storms will be moving to the northeast.


By the afternoon, more storms may develop, and these would have a better chance of producing some rainfall.  While north-central Washington stands the best chance, northeast Washington is also possible.



This wave will knock about 10 degrees off the temperature on Monday.  Another dry cool front will move by on Tuesday, bringing breezy afternoon winds for much of the week and keeping temperatures more moderate.  But the heat is expected to return by next weekend.  The high pressure responsible for all the heat in the desert SW will build northward into our area next weekend.  How long it sticks around is still in doubt.  About 40% of the models say the heat will break after a few days, while 60% of them say the heat will stick around.




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