What to look forward to during the July 4th weekend.
Big Idea
- Possible scattered showers today and tomorrow
- Starting Monday, a drier northeast flow will arrive
- Decreased storm activity and increasing temperatures
- Read more...
Possible rain this weekend, then drier temperatures
SYNOPSIS...Scattered shower and thunderstorm activity will continue each afternoon and evening through the 4th of July.
Starting Monday a drier northeast flow and strengthening high pressure will usher in decreasing storm activity and increasing temperatures through the week.
DISCUSSION...High pressure in the mid to upper levels was centered near the Four Corners during the morning hours. Over the coming week and heading into next weekend this high center will gradually wobble westward and strengthen.
For today and the 4th of July...The high pressure center will remain near the Four Corners with monsoon moisture entrenched across the area, especially from the Mogollon Rim southward. The result will be scattered to numerous afternoon and evening thunderstorms from near Interstate 40 southward with activity more isolated to the north. A bit drier air to the north will also allow for very hot temperatures to develop across the lower reaches of the Grand Canyon where an Excessive Heat Warning, with high temperatures hovering around 110 degrees, will go into effect this afternoon and continue through Sunday. A few severe thunderstorms with wind gust in excess of 55 mph will be possible across the lower elevations of Yavapai and Gila counties including locations such as Camp Verde, Black Canyon City and Congress.
From Monday onward...High pressure will gradually shift westward and strengthen becoming centered over Nevada by next Friday, strengthening from a 5930 meter central 500 mb height today to a 5990 meter central height by Friday. What does this mean? The position shift of the high to Nevada will enhance northeast flow across the state pushing drier air to areas north of the Mogollon Rim, especially north of Interstate 40, with a near shutdown of storm activity. Further south monsoon moisture will remain in place with isolated to scattered showers and storms continuing.
However, the strengthening high could even start suppressing activity further south due to warm capping air aloft. A stronger high also means climbing temperatures. In the dry air to the north of Interstate 40 a few record high temperatures could be set next week. In addition, the Excessive Heat Watch for the lower elevations of the Grand Canyon will continue through Friday where high temperatures could touch 115 to 118 degrees (it just depends on how much the drier air mass takes over). Further south, where moisture is more entrenched, high temperatures will go above normal but likely remain below record levels. Unfortunately the humidity will likely make it feel less than optimal.
