Area Forecast Discussion
Issued by NWS Tucson, AZ
Issued by NWS Tucson, AZ
665 FXUS65 KTWC 122014 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 114 PM MST Sat Sep 12 2026 .SYNOPSIS...A more typical isolated to scattered coverage of storms is forecast this weekend into next week. Daily high temperatures will fluctuate between near normal and a few degrees below normal. && .DISCUSSION...Scattered storms already ongoing and continue to fill into the Tucson Metro which is no surprise given the moisture profile in place today in conjunction with sufficient instability. We`ll mainly be monitoring for heavy rainfall this afternoon as scattered storms with frequent lightning continue to evolve, but can`t rule out strong gusty outflow winds. With very weak flow in the atmosphere, the storms that do form have the potential to dump an impactful amount of rain over the same spot resulting in water flowing in normally dry washes and low water crossings becoming inundated with swift moving water. HREF depicts a slight chance (10%) for rainfall totals exceeding 3 inches. If storms do gradually evolve into the Tucson Metro proper, we could see urban street flooding with ponding of water on roadways and in poor drainage areas. This weekend chances for isolated to scattered storms continues, again with the moisture we have in place the primary concern continues to lean toward heavy rainfall and localized flash flooding. Monday still looks to be a bit more active as a weak disturbance moves across southeast Arizona. Combined with the additional moisture we have in place, any lifting mechanism can help provide confidence in a heavy rainfall event. QPF continues to trend up with WPC placing portions of the forecast area under slight risk for excessive rainfall with the potential for stronger storms producing rainfall rates of 1-2"/hr leading to the increased risk of localized flash flooding. Time will tell as its difficult to time disturbances this far out. && .AVIATION...Valid thru 14/00Z. SCT SHRA/TSRA thru 13/04Z. SFC winds WLY/NWLY 6-10 kts thru 13/05 becoming terrain driven and less than 10 kts thereafter. Tomorrow, ISOLD-SCT SHRA/TSRA aft 13/17Z. SFC winds WLY/NWLY at 6-10 kts. Visibility 1-3 SM possible in TSRA. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A typical isolated to scattered coverage of storms is forecast this weekend into next week. High temperatures will will fluctuate between near normal and a few degrees below normal. Min RH values mainly 20 to 45 percent in the valleys and 35 to 65 percent in the mountains over the next week. RH recoveries will continue to be excellent overnight. Winds will generally remain less than 15 mph and terrain driven. Gusty and erratic winds will accompany thunderstorms. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ DVS Visit us on Facebook, X, YouTube...and at weather.gov/Tucson