To date, the Southwest Monsoon has been a dud along the Colorado Front Range. Unlike the upslope storms of spring, which douse the entire region with rain or snow, monsoon rains are generally associated with thunderstorms and precipitation coverage is often spotty. Indeed, over the past week I have watched as impressive thunderheads passed to our north or south, offering no benefit to our parched Littleton farm.
Fueled by high pressure over the Southern Plains and low pressure over the Baja region, the Southwest Monsoon begins in June for Arizona and New Mexico and generally arrives in Colorado by mid July; in most years, its welcome rains fall intermittently through August (see Colorado's Monsoon Season). Depending on the position and strength of the atmospheric engines, the monsoon season may bring copious precipitation or barely dent the summer heat and drought.
Many of us have an eye on Tropical Storm Javier, currently churning south of Cabo San Lucas. As it moves northward, up the Baja Peninsula, it may inject tropical moisture into the monsoon flow, igniting thunderstorms across the Four-Corners region and, hopefully, drenching the Front Range. We should know by this coming weekend.