The weather pattern along the West coast from Washington state to California is very dull. In general, there is a ridge of high pressure at 500 mb in control.
This high is providing warm temperatures away from the immediate beaches but not excessively hot weather as we had in portions of Southern California late last week and over the weekend. Temperatures will be averaging above normal.
There is a broad and relatively weak, closed low well west of the southern Oregon/northern California coast. While this spins well offshore the next couple of days, it will eventually head east by Friday and the weekend. Models are in agreement on this. What they are not in agreement on is how far south the low will go. The main effect on the weather would be on how much cooler air occurs, especially in central and Southern California. Precipitation is not going to be much, though there could be a mainly afternoon shower or thundershower in a few spots over Oregon, northern California and northern Nevada. Monsoon moisture is not going to be a player.
This is some serious and dangerous heat. Outdoor activity is just not at all recommended during the daytime.
A strong ridge of high pressure in the West brings the highest heat of the season so far to a large area.
Combine the cold with the wind and some precipitation and there is a real danger of hypothermia.
Any shower and thunderstorm can contain heavy downpours, heavy enough to cause temporary, low-lying ponding.
According to all long-range models, the warmest area in North America compared to average will be over the Northwest.
No matter where you are, the sunshine gets more intense and causes quicker burning