Western Tucson, AZ 
640 FXUS65 KTWC 052036 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 136 PM MST Sat Apr 5 2025 .SYNOPSIS...Unsettled conditions into this evening as a weather system results in scattered light precipitation from the Tucson area eastward. Next week a strong ridge of high pressure will move into the area. This will bring a significant warm-up in afternoon temperatures through next week. && .DISCUSSION...Our forecast area still remains under the influence of the back side of an upper low now centered near El Paso. The combination of wrap around moisture and an embedded disturbance moving SW on the back side of the low is resulting in isolated to scattered showers mainly across Graham/Greenlee/Cochise Counties at this time. From Tucson westward, skies are partly to mostly sunny as dry conditions prevail. As the aforementioned disturbance continues to move S/SW, isolated to scattered shower activity could reach as far west as Tucson later this afternoon into the early evening and the latest HRRR/HREF depicts this scenario. QPF amounts are low at generally less than 0.10" with any shower activity with locally higher amounts on the Sky Islands which translates to an inch or two of snow, and perhaps 3 to 4 inches for the White Mountains in northern Greenlee County. Given the cold temperatures aloft, there will be enough instability for an isolated rumble or two of thunder with these showers as well. As the upper low continues to move east tonight, shower chances diminish with dry conditions returning areawide after midnight. Sunday will feature northerly flow between the upper low and ridging aloft to our west with temperatures rising a several degrees compared to today. Thereafter, broad ridging early in the week gives way to strong ridging as anomalously high heights for this time of year build in. Expect daytime high temperatures for Tucson to push into the 90s by midweek with mid to upper 90s Thursday and Friday with daily record highs in jeopardy. At this time, Friday looks like the hottest day and the latest NBM shows a 41% chance for Tucson to reach or exceed 100 degrees. Temperatures then drop slightly next weekend as heights begin to lower ahead of some upstream troughing. && .AVIATION...Valid through 07/00Z. SCT to lcly BKN clouds 4k-8k ft AGL mainly from KTUS E with SCTD -SHRA though 06/06Z resulting in Brief MVFR conds. SKC-SCT clouds 4- 8k ft AGL west of KTUS. Clouds diminish rapidly aft 06/06Z with SKC conditions returning areawide. Sfc winds NWLY 8-12 kts til 06/00Z then becoming ELY/SELY til 06/21Z. Sfc winds then shift to NLY through the end of the forecast period. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...The area will be on he back side of a weather system moving through southern New Mexico into this evening. This system will bring a chance of valley rain and mountain snow to Graham, Greenlee and Cochise counties with the eastern parts of Pinal, Pima and Santa Cruz counties on the western edge of these chances this evening. Then a strong ridge of high pressure will move into the area bringing with it a significant warm-up in afternoon temperatures next week. Daily SFC winds will see afternoon gustiness. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
