NWS Forecast Office Phoenix, AZ

Showers and storms on Tuesday have saturated soils across portions of the region, especially along Northern and Western Maricopa County. The slow moving low pressure system that is currently situated just west of the region will make for a long duration of favorable moisture and forcing for additional rounds of showers and isolated thunderstorms. As such, a Flood Watch has been issued for Northern Maricopa County, with the western half valid through 5 PM MST Wednesday, and the Eastern half valid through 6 AM MST Thursday.

A slow moving area of low pressure will help keep rain chances in the forecast through the middle portion of the week. Multiple rounds of rainfall will move through the area with portions of Southern and Central Arizona likely seeing the highest totals. Main impacts from this system will be isolated thunderstorms, locally gusty winds associated with any thunderstorms that form, and impacts to travel from wet roads, ponding water, and washes flowing over low water crossings.

With the long residence time of the incoming low pressure system just west of the region, expect additional rounds of showers with a few isolated thunderstorms Wednesday/Wednesday Night and even into Thursday across South-Central AZ. Rainfall totals remain heavily dependent on where lines of showers/isolated t-storms set up and train over the same spot as they stream northward across the area.

Unsettled weather conditions will continue into the weekend with periodic chances for rainfall. Temperatures throughout the week will remain below the daily normals with readings more than 10 degrees below normal midweek.