Amazingly Wet July Day on Wednesday

8 AM update

Lots of heavy showers and thunderstorms moving through  here is the latest radar.  Yellow are heavy showers....and there are even some reds (downpours or hail) in a few cells.

and the lightning during the half-hour ending 7 AM in shown below.  Not much lighting in easternWA yet. Lots on the eastern side of Puget Sound.

*We are now entering the climatologically driest period of the year, with the last week of July/first week of August being the most arid of the year.  July is usually our driest month, and this year has been drier than most (only a trace of rain so far at Sea-Tac airport).

But everything changes tomorrow, when a July deluge is forecast by our weather forecasting models.

Just to impress you.  Here is the 48h total precipitation predictions to occur starting 5 PM Tuesday and ending 5 PM Thursday.  Wow.  The western slopes and crest of the Cascades get hammered, with totals of 1-3 inches.  Even the western lowlands get quite wet, with modest amounts extending into eastern Washington.  Not a good time for hiking or camping in the Cascades.

This heavy rain is associated with the approach of a sharp upper-level trough/low (see upper-level map for 5 PM on Wednesday.)  Pretty impressive this time of the year.

This air is potentially unstable and there could well be some embedded thunderstorms.

The rain should start moving in around 8 AM

 Strengthen and move northward during the day

Transition to showers as the low passes by on Wed. night

And then we get more rain on the backside of the low on Thursday AM

I am worried about eastern Washington getting light rain, including some thunderstorms--with the potential for more lightning induced fires.  And there is the potential for strong winds over both western and eastern Washington as the trough/low move through.

I expect several local stations to exceed their daily records if the models are right.