Area Forecast Discussion
Issued by NWS Tucson, AZ
Issued by NWS Tucson, AZ
834 FXUS65 KTWC 071603 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 903 AM MST Mon Sep 7 2026 .SYNOPSIS... Expect isolated to scattered thunderstorms each afternoon and evening into early next week, with a potentially more active period towards the end of this week. The main threat will be heavy rainfall leading to localized flash flooding. High temperatures will will fluctuate between near normal and a few degrees below normal. && .UPDATE... Partly to mostly cloudy skies this morning across most of southern Arizona with isolated showers from this morning gradually dissipating. Showers, currently focused to areas Tucson westward, will continue to dissipate and cloud cover will lessen. Storms and showers this afternoon will depend on how efficiently the clouds can clear out of the area. The greatest chance for early clearing and subsequent storms and showers will be focused to areas south and east of Tucson. Current CAMs have development as early as 1:00 PM along the higher terrain. Moisture continues to surge into southern Arizona with satellite derived PWATs now 1.4 to 1.7 inches as far east as central Cochise and Graham counties. Like the past few days, the main concern will be locally heavy rainfall that could lead to localized flash flooding. && .DISCUSSION... Currently there is isolated to scattered showers across Southeastern Arizona, with the most activity in areas east of Tucson in Cochise, Graham, Santa Cruz and SE Pinal counties. Rainfall accumulations have been light with less than 0.10 inches. The latest CAMS are struggling to get a handle on the timing and placement of this activity, however this activity should move north/northeastward out of the area by mid morning. Since the CAMs are struggling with this activity, it still has showers/thunderstorms today beginning in the mid afternoon, however depending on how much cloud cover can exit the region the start for any activity can be delayed. Best chances for activity is where the best instability is areas south and east of Tucson. Locally heavy rainfall with isolated flash flooding remains to be the primary impact with stronger storms. Storm activity and coverage will slowly increase this week, with the more active days looks to be Wednesday and Thursday as the area of high pressure moves eastward overhead, introducing more daytime heating and instability, as well as easterly to northeasterly flow aloft. The available moisture continues to have flash flooding as the primary threat, however stronger storms during this time can be capable of strong outflow winds as well. Temperatures will be within a couple of degrees of normal through Thursday, then dropping to below normal levels through the weekend into early next week. && .AVIATION /15Z MONDAY THROUGH 15Z TUESDAY/... Valid thru 08/12Z. FEW to SCT clouds between 10-15 k ft AGL today. Isolated TSRA along the International Border and AZ/NM border with VCSH and possibly VCTS for KOLS, KFHU, and KDUG from 07/21Z thru 08/6Z. SFC winds less than 12 kts, with the exception of any outflows around convection. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER... Expect daily isolated showers and thunderstorms into early week, before becoming more scattered the rest of the week. Heavy rainfall leading to flash flooding will be the main threat. Temperatures will be around normal to a few degrees below normal into early next week. Minimum relative humidity values mainly 20 to 45 percent in the valleys and 30 to 60 percent in the mountains over the next week. Winds will generally remain less than 15 mph and terrain driven through the week. && .TWC WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Malarkey DISCUSSION...Tetrault Visit us on Facebook, X, YouTube, and at weather.gov/Tucson