A pattern change across much of the West will bring in both cooler air and a brief dry spell; however more monsoonal moisture will return to the Southwest soon.
Over the weekend, temperatures will soar across California. In addition to triple-digit temperatures
However, the record-challenging heat will subside for early next week.This high pressure shifting east will gradually drop temperatures across the Central California valley’s and then the remainder of the Southwest.
“The first to feel these changes will be California, when temperatures will start trending down after Sunday.The temperature difference will be noticeable in cities like Fresno, California, Flagstaff, Arizona and Las Vegas. From their peak on Sunday and Monday afternoon, high temperatures will drop 10-15 degrees F by Wednesday afternoon.
Overall, temperatures across the state of California will be within a few degrees of normal by the middle of the week. Fresno, California will reach the upper 90s in the afternoon, while Palm Springs returns to the lower 100s.
An onshore flow off of the Pacific Ocean will continue to keep it cool along the beach of California.”As the high moves east early in the week, the core of the heat will position itself over the Rockies by the middle of the week,” Vido added.
Temperatures will trend a few degrees higher Tuesday and Wednesday for places like Santa Fe, New Mexico, Casper, Wyoming and Denver.The temperature swings in these locations are not expected to be quite as drastic as that across California, Nevada and Arizona.
Part of the reason for this will be the location of the high over northwestern Texas. The clockwise flow around the high will help to steer moisture from Mexico back into the Southwest. The increased moisture will lead to more clouds which will block the summer sunshine, and even more thunderstorm activity, both of which will put a cap on the heat.
After a break from widespread thunderstorms early in the week, a surge of monsoonal moisture will once again bring the threat for flooding downpours.As is typically the case during the monsoon, thunderstorms will tend to blossom over the highest terrain during the afternoon hours and drift toward the lower elevations into the evening and overnight.