Area Forecast Discussion
Issued by NWS Tucson, AZ
Issued by NWS Tucson, AZ
630 FXUS65 KTWC 291936 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 1236 PM MST Wed Jul 29 2026 .SYNOPSIS... Expect daily afternoon and evening showers and thunderstorms through the weekend with day to day variability in coverage and strength. High temperatures will warm to 7-12 degrees above normal Thursday into the weekend with an Extreme Heat Warning through Sunday. && .DISCUSSION... GOES sounder profile and SPC mesoanalysis shows the atmosphere eroding the last remaining CIN values across the area. There has been ample sunshine to continue eroding CIN and there are a few towering cumulus clouds forming over the eastern Sky Islands. All indications for an active afternoon for areas south and east of Tucson. These areas have the best ingredients to support thunderstorms due to shear values of 10-20 kts and CAPE greater than 1500 j/kg. A few storms will reach Tucson metro to bring gusty winds and light to moderate rain showers. 12Z HREF model has 70% chances for wind gusts greater than 35 mph in Cochise County and into eastern Santa Cruz County this afternoon. There can be a few storms capable producing a severe level wind in the afternoon. Storm`s will be capable producing up to 0.75-1 inch total with Santa Cruz County having at least 50% of receiving an inch or more through the late evening. There will be a risk for flash flooding along the International Border between Nogales and Naco. The ridge of high pressure will start to build west starting tomorrow. Temperatures will be increasing 10-15 degrees above seasonal normals. This will push the region into Major and Extreme HeatRisk tomorrow through Sunday. The hottest days will be Friday and Saturday with temperatures reaching up to 113F. Tucson has 112F on Saturday. Extreme Heat Warning is in effect Thursday through Sunday evening. Thunderstorm chances will be generally low tomorrow and Friday due the lack of upper level support. There will be plenty of instability to get vertical growth. The best areas for any thunderstorm growth will be south and east of Tucson. Chances will increase for Saturday and Sunday. Next week, right after this heat, the upper level flow will return from the east to southeast with the high pressure center close to the Four Corners. This set up will provide better daily chances for thunderstorms and rain showers. && .AVIATION...valid through 31/00Z. SCT clouds AOA 15k ft AGL this morning becoming SCT-BKN 8k-12k ft AGL this afternoon and evening south and east of KTUS. Isolated to scattered TSRA will be possible 29/20Z-30/03Z with KOLS and KDUG terminals having the best chances to be impacted by TSRA. KTUS has a 10 percent chance for TSRA. Near thunderstorms wind gusts 30-40 kts will be possible. Surface winds NWLY 6-10 kts with occasional gusts this afternoon and evening and again after 30/18Z. In the overnight hours, winds will be less than 10 kts and variable. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER... High temperatures will remain well above normal this week with an Extreme Heat Warning in place Thursday through Saturday. Expect daily chances of afternoon and evening showers and thunderstorms mainly south and east of Tucson through the weekend with some day to day variability in coverage. Early next week storm coverage and chances are expected to increase. Any thunderstorm will bring a threat of severe, erratic wind gusts as well as brief heavy rainfall and an isolated threat of flash flooding. Min RH values will be 10-20 percent tomorrow into the weekend. Winds will be terrain driven 5 to 10 mph. && .TWC WATCHES/WARNINGS/ADVISORIES... Extreme Heat Warning from 10 AM Thursday to 8 PM MST Sunday for AZZ501>509. && $$ Visit us on Facebook, X, YouTube, and at weather.gov/Tucson