Storms are firing up over Southeast Arizona

Tucson residents should prepare for a quick swing in weather over the next several days, with thunderstorms and locally heavy rain giving way to sunshine and near triple digit heat before a more substantial cooldown arrives early next week. Storms are already developing across Southeast Arizona, and forecasters say the strongest cells could produce heavy rainfall and an isolated flash flood threat. The changing pattern will affect commutes, outdoor plans, hiking conditions and neighborhoods vulnerable to runoff.

Moisture moving north from Mexico is helping create mostly cloudy conditions and a better chance of afternoon and evening showers and thunderstorms across the region. The clouds may limit the overall number and strength of storms, but stronger thunderstorms remain capable of producing heavy rain. The current unsettled period is expected to continue through Thursday, followed by a brief push of drier air on Friday and Saturday.

For Tucson, temperatures are expected to remain in the low 90s during the first part of the pattern, with overnight lows in the upper 60s. Skies should clear Friday, when highs are forecast to climb into the mid 90s and nighttime temperatures settle in the low 70s. The warmup peaks Saturday under mostly sunny skies, with temperatures reaching the upper 90s, near 96 degrees, and overnight lows in the mid 70s.

Clouds are expected to increase again Sunday, holding daytime temperatures in the low 90s and keeping overnight readings in the mid 70s. Moisture will begin returning to Southeast Arizona late in the weekend, bringing back the chance of showers and thunderstorms. The outlook is still developing, but the forecast becomes notably wetter beginning Monday.

Scattered thunderstorms are expected Monday, with the possibility of heavy rainfall and temperatures falling into the 80s. Showers and additional heavy rain chances continue Tuesday, while Tuesday night lows could drop into the mid 60s as cooler autumn air settles across the region. That combination of renewed moisture and lower temperatures could mark a more meaningful shift away from the late summer heat, although the exact placement and intensity of storms will determine which communities receive the most rain.

Forecasters are also watching tropical systems that could influence Arizona’s weather. Hurricane Polo is being tracked for possible effects next week, while another forecast includes Hurricane Odalys as a second system that could send tropical moisture into the state from Sunday through Tuesday. There is uncertainty about how far north that moisture will travel as the hurricanes weaken. An area of low pressure will also help determine how much rain reaches central and southern Arizona.

Recent storms elsewhere in the state illustrate how quickly conditions can change. Phoenix experienced strong morning storms, cloudy skies and a high of 88 degrees, below average for the area, while additional activity was expected near higher terrain north and east of the Valley. Flood watches and warnings issued for the morning storms there had expired, but the broader forecast still called for active weather before drier air returned for the weekend. In Southern Arizona, residents should likewise be ready for changing conditions even during a short period of clearer skies.

Heavy rain can create dangerous driving conditions, especially where water collects on roads or crosses low water routes. Safety guidance emphasizes that drivers should never enter a flooded roadway and should turn around when water blocks the route. If water begins rising around a vehicle, occupants should leave quickly and move to higher ground. People in flood prone neighborhoods should be prepared to evacuate, follow official instructions and wait for authorities to say an area is safe before returning.

Households can prepare for storms by keeping flashlights and extra batteries available, storing at least one gallon of clean water per person, maintaining a first aid kit and having backup power for phones and essential medical devices. A safe indoor location should be away from windows, skylights and glass doors. Downed power lines should not be approached because the surrounding ground may remain energized. During the warmer days, health officials also recommend limiting strenuous outdoor activity during the hottest part of the day, drinking water before, during and after exercise or outdoor work, and checking on friends, family and neighbors who may be at higher risk from heat.