Pattern Change This Week to Keep East Relatively Cool as a Heat Wave Moves Into Parts of the West
Much of the East will be relatively cool for June as intense heat builds into the West from a weather pattern change setting up across the Lower 48 this week.
The jet stream is becoming amplified, as it takes a pronounced southward plunge east of the Rockies. When that happens, the jet stream tends to build northward in the West. This is somewhat unusual for this time of year since the jet stream typically runs in a flatter west-to-east fashion near the Canadian border during the summer months.
As a result, this week's forecast has contrasting temperatures from coast to coast. Rainy conditions will also continue to plague parts of the East.
San Francisco (downtown) tied its daily record high of 91 degrees on Sunday afternoon, then set a new daily record high on Monday, with a high of 97 degrees. San Francisco International Airport reached 100 degrees on Monday, also a record high for the date at that climate site and the first time on record they've hit the century mark in any month other than September, according to Scott Rowe, a meteorologist at the National Weather Service.
Monterey, California, set a new all-time record high for meteorological summer (June-August) on Monday, when it topped out at 97 degrees at the airport. The previous all-time record between June and August was 94 degrees, according to Philippe Papin, an atmospheric scientist at the U.S. Naval Research Laboratory in Monterey. This also smashed the daily record high for June 10, which was only 77 degrees.