Fall Rains on the Horizon

September is starting off on a hot note.  We could be looking at several 90+F days over the next week, well above the normal 2 such days in an average September.  This is all compliments of a large area of hot high pressure along the West Coast as well as western Canada.

The heat should peak on Saturday or Sunday, and then very slowly subside next week.  A very weak weather disturbance could lead to some mountain thunderstorms on Sunday.  But the main cooling will begin as the high pressure shifts to the east and a large area of lower pressure develops off the coast.

This pattern will slowly shift eastward allowing progressively cooler air to infiltrate the Inland NW.

Then this pattern will become rather stationary for the latter half of next week.  In other words, this isn't our typical fall front that brings us some wind and a little rain for a day.  Instead, this will set up a rather wet pattern for this time of year, with a chance of rain for multiple days, out to at least the 20th of September and possibly beyond.

On average, September is the third driest month of the year.  So we typically don't expect to see a lot of rain in this month.  Right now it looks like we could see a quarter inch of rain for the latter half of next week.  But as I said, this pattern could continue beyond that so we'll have to see how much rain falls.  

But overall, after this hot stretch of weather in the next 5-7 days, there's a good chance we won't see any more 90s for the rest of the year.

By the way, some of you may have heard about the impressive record Phoenix set with 100 consecutive days of 100+F temperatures.  Turns out they shattered their old record of 76 consecutive days set back in 1993.  Phoenix will usually have enough clouds and showers from their monsoon to keep the temperatures in the 90s for at least a day here and there.  But not this year.

And in case you're wondering, the forecast is for temperatures to be around 110F for at least the next 10 days.