309 FXUS65 KTWC 102045 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 145 PM MST Thu Jul 10 2025 .SYNOPSIS...Temperatures remain in the triple digits across the lower desert today, with isolated thunderstorm chances mainly confined to the International Border this afternoon and evening. && .KEY MESSAGES... - "Low-grade" monsoon pattern for the next several days. Storms and showers that develop will generally be east and south of Tucson. - Decreasing temperature trend for the next 7 to 10 days. Near normal temperatures by early next week. Minor to localized Moderate HeatRisk. - Monsoon pattern ramps up again as early as Sunday. .DISCUSSION... Clouds and weak thunderstorms are starting to build up along the Chiricahuas and the White Mountains. Another hot day today with high temperatures between 100 to 108 degrees with widespread Moderate HeatRisk and localized Major HeatRisk in the Gila River Valley. Moderate HeatRisk means that most individuals sensitive to the heat will be will affected if they do not have effective cooling or adequate hydration. Slight chance (15-30 percent) for showers and thunderstorms this afternoon. The unfavorable northwest flow aloft continues and moisture recedes southward into Mexico localizing the chance for thunderstorms to far southeastern Cochise county along the International Border. It will be breezy this afternoon and tomorrow afternoon in the Gila River Valley with sustained northwest winds of 20 25 MPH with gusts to 35 MPH leading to near critical fire weather conditions. With westerly flow at the surface overnight and a Gulf Surge setting up from the Gulf of California, moisture will increase across southern Arizona tomorrow morning increasing afternoon surface dewpoints into the upper 50s to low 60s. Mid to upper level wind alignment is still not in a great position, northwesterly, and while there is a touch more moisture it will mix out thus the concern for thunderstorms is minimal (10 to 20 percent chance) and focused to areas along the International Border from Nogales eastward. The high pressure aloft will gradually continue to weaken and elongate southwestward over the next several days, centering over northern Baja by tomorrow morning. Because of the evolution of high pressure, temperatures at the surface will gradually cool over the next 7 to 10 days to near normal by the beginning of next week. As the aforementioned high moves out of our area, another high will start to build leading to better wind alignment, north to northeast, beginning as early as Sunday. The new high will continue to develop and strengthen into a Four-Corners-High in the next 7 to 10 days. Thanks to this development, we will see an uptick in daily thunderstorm activity. Early next week, while moisture is starting to return to the area, daily thunderstorm chances will initially be east of Tucson expending to west of Tucson by the middle of next week. Until we get sufficient moisture, the main concern with these storms will be strong, gusty outflows. By the end of the week, when moisture is greater and the atmosphere is more saturated, the concern with thunderstorms will be flash flooding and strong, gusty outflows. && .AVIATION...Valid through 12/00Z. Surface winds are around sustained 5 to 10 kts from the northwest gusting to 20 kts, southwest of KSAD this afternoon and tomorrow afternoon. At and near KSAD winds will be sustained from the northwest around 20 kts with gusts to 30 kts. Overnight, winds will weaken to less than 12 kts across southern Arizona. FEW to SCT clouds are developing over the Sky Islands east of KTUS AOA 10 to 15k ft AGL otherwise SKC. Clouds will continue to be FEW to SCT east of KTUS until 11/04Z then will dissipate overnight. && .FIRE WEATHER... Isolated to low- end scattered thunderstorm coverage is expected to the south of Tucson, along the International Border into the weekend. The main threat for storms will be the potential for strong gusty and erratic outflow winds 40-45 mph. Otherwise, an uptick in monsoon activity is possible later this weekend and into next week as the upper high shifts to a more favorable location aloft. Temperatures will remain above normal this week, and back to near normal by mid to late next week. Winds will remain generally light and under 15 mph with the exception of stronger winds in the Gila River Valley today and tomorrow with northwest sustained winds around 15 to 20 MPH gusts to 30 MPH. && && .TWC WATCHES/WARNINGS/ADVISORIES... None. && $$ Malarkey Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson