May 31st, 2025: Showers and Thunderstorms Across Arizona Through Sunday Night
Synopsis An upper level cutoff low will remain anchored off the coast of Northern Baja California today before lifting rapidly northward across Arizona tomorrow. This feature is drawing tropical moisture northward from former EastPac TC Alvin into the Southwest CONUS. The majority of shower and storm coverage will remain in Mexico and extreme Southern California through this evening, but by tomorrow precipitation chances will shift into Arizona as the aforementioned low lifts northward across our region. Models forecast impressive precipitable water values near 1.50 inches tomorrow which would be record breaking for June 1st in AZ. A combination of synoptic scale ascent, deep moisture, and modest instability will generate numerous showers with embedded thunderstorms across the state tomorrow afternoon and evening. Total rainfall will be highly variable and dependent on the frequency and intensity of showers and storms. In general, expect 0.1 to 0.5 inches across the lower deserts w...