Area Forecast Discussion
Issued by NWS Tucson, AZ
Issued by NWS Tucson, AZ
261 FXUS65 KTWC 111541 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 841 AM MST Fri Jul 11 2025 .SYNOPSIS...Above normal temperatures continue through the weekend. Expect isolated thunderstorms limited to areas near the international border from Nogales eastward through Saturday. An increase in monsoonal activity on Sunday, especially for locales east of Tucson and then next week for the entire forecast area. As moisture and storm chances increase next week, temperatures will drop back down to seasonable levels. && .UPDATE...Clear skies across southeast Arizona this morning but with noticeably more humidity as dewpoints have jumped into the 60s for all valley locations as a Gulf Surge continues to help push moisture into the area. Even though we will have increased lower level moisture, it will mostly go to waste as other factors aren`t conducive for active monsoon activity. An east-west elongated mid/upper level high is located from southern Arizona to off the southern California coast. This is resulting in continued northwesterly flow aloft with continued mid level drier air advecting in. The combination of this drier air and subsidence aloft will result in some mixing out of the lower level moisture with isolated to low end scattered thunderstorms chances primarily confined to the southern half of Cochise County this afternoon with slight chances extending as far west as Nogales. We went ahead and modified the PoPs to better reflect this geographical focus area. Otherwise, no other updates this morning. See previous discussion below for additional information. && .KEY MESSAGES... - Another dampened monsoon pattern for Friday and Saturday. - Decreasing temperature trend for the next 7 to 10 days. Near normal temperatures by early next week. Minor to localized Moderate HeatRisk. - Monsoonal activity ramps up again as early as Sunday, with increased moisture. .DISCUSSION... Upper level ridge will shift to the west the next few days, which will aid in a gradual downturn in daytime high temperatures. We are not completely out of the woods, however, as HeatRisk values will still fall firmly within the Minor to Moderate range for the next several days. With the retrograde of the ridge axis to the west, we`ll be under the influence of more northerly winds, which will likely shut down much in the way of moisture for any real sustained convective activity through Saturday. Slight chances for afternoon/evening isolated thunderstorm activity - mainly confined to the far southern portions of AZ - will be possible the next few days, with the main concerns being gusty winds. A more favorable monsoonal pattern will start to take shape by Sunday evening as a high develops over the Four Corners region, allowing for more ample moisture transport into southern Arizona. This is consistent with the latest CPC 6 to 10 Day outlooks have most of the area with a 20-40% chance of above normal precipitation with below normal temperatures. Monday and Tuesday will see some more widespread shower and thunderstorm activity, with the Tucson Metro Area possibly getting in on the action. && .AVIATION...Valid through 12/12Z Sustained winds will primarily be westerly from 5-10 kts this morning. After 18Z, expect occasional gusts from 20-25 kts. KOLS and KDUG will see increasing clouds between 18-20Z AOA 10 to 15k feet. Otherwise expect SKC at all terminals. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER... Isolated thunderstorm coverage is expected to the south and east 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 beginning Sunday and into next week as the upper high shifts to a more favorable location aloft. Temperatures will remain above normal for the next few days, and back to near normal by mid to late next week. Winds will remain westerly from 10-15 mph, with occasional gusts at or above 20 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. Afternoon RH values in the low lying areas will be between 20-25%. && .TWC WATCHES/WARNINGS/ADVISORIES... None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson