TODAY-TONIGHT: A SLIGHT RISK of showers this afternoon. A HIGH RISK of rain showers this evening. Periods of rain and rain showers are LIKELY overnight. FRIDAY: Periods of rain and rain showers are LIKELY along with a SLIGHT RISK of thunderstorms. A developing upper-level low-pressure system will stall tonight to the west of the Valley (over southern California and northern Baja California). The low will bring in a flow of moist sub-tropical air into Arizona, send a series of rain-producing disturbances over the state and form a cold front over central Arizona that will stretch from west of Tucson north through Maricopa County and on to Flagstaff. This front will not move much through Friday and is expected to be the focus of the heaviest rainfall in the state. A half inch to one inch of rain is likely in the Valley tonight with additional similar amounts during the day on Friday. Rains are forecast to diminish some on Saturday as the front weakens and moves east. Rain will decrease rapidly once the upper low moves east of the Valley on Sunday.
Posted on: Thu, 21 Nov 2013 21:49:04 +0000