TONIGHT: Mostly clear this evening with lows in the upper 50's to low 60's near theSound and the mid to upper 50's inland. Low clouds developing along the coast and north and west of Everett. North winds 5-15 mph.
Puget Sound Forecast: Partly cloudy with a chance of thundershowers. Highs in the mid to upper 70's near/along shorelines, and the low to mid 80's 5 or more miles inland.
Coast Forecast: Low morning clouds and local fog, sunbreaks or partly sunny in the afternoon with a chance of a thundershower. Highs in the 60's, west winds 10-20 mph.
Mountain Forecast: Mostly cloudy with thundershowers; snow level 12,000 to 12,500'. Pass highs in the mid 70's to low 80's. Pass winds westerly 5-15 mph.
Eastern Washington Forecast: Mostly cloudy with thundershowers. Highs in the mid 90's to near 100.
Radar now is picking up showers off the coast and over the south Washington Cascades. That flow of moisture is coming from what we call the 'summer monsoon' to direct some thundershowers northward from the Rockies and Sierra Nevada. It's becoming apparent the Cascades won't be the only area at risk of thundershowers Friday, but also western Washington. Now these thundershowers are likely to have very high bases, which means much of the rain falling out of them will likely evaporate before reaching the ground. That would leave lightning, so called 'dry lightning' which of course could spark fires on the ground.
The disturbance likely to set off those thundershowers will shove more ocean air inland this weekend. That will likely end the threat of any thundershowers over western Washington, but lead to low morning clouds. Partly to mostly sunny skies are likely to develop during the afternoon...but slightly cooler temperatures...with highs mostly in the upper 70's to low 80's. Monday and possibly Tuesday could warm up a bit, into the low to mid 80's, followed by another push of ocean air and gradual cooling Wednesday and Thursday.
Jeff Renner / KING 5 Chief Meteorologist