Area Forecast Discussion
Issued by NWS Tucson, AZ
Issued by NWS Tucson, AZ
949 FXUS65 KTWC 030830 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 130 AM MST Sat Jan 3 2026 .SYNOPSIS...Dry conditions prevail through early next week. Above normal high temperatures continue through Sunday, lowering to seasonable levels Monday and Tuesday, then below normal Wednesday and thereafter. A storm system is expected the middle of next week and will provide another round of valley rain and mountain snow. && .DISCUSSION... A few high clouds are beginning to stream into the area from the west as mid to high level moisture is being funneled into the area. A deepening trough off the coast of Oregon with several embedded disturbances will gradually push south over the next several days and a shortwave ridge is building into southern Arizona. A dry shortwave trough will move through the region tonight into tomorrow shifting the winds aloft to be southwest. Clouds will continue to stream into the area becoming partly cloudy by this afternoon. Temperatures will remain above normal this weekend. Southwest winds will continue as the ridge is pushed east and the Pacific trough continues to descend south. Dry conditions will continue through Monday. This Pacific trough will finally push onshore into northern Baja Tuesday night/ Wednesday morning and then generally pushes into northern Sonora, MX/ Southern Arizona. Ensembles focus the best precipitation chances to be from Tuesday night through Thursday morning for most areas and lingering through Friday north of Tucson as a secondary disturbance within the trough may impact the region. This system will result in valley rain, high level mountain snow with snow levels mostly above 7000 feet and below normal temperatures. Still quite a bit of spread in the ensembles for storm total QPF with the Euro and Canadian on the lower side ranging between 0.1-0.25" while the GEFS has up to 0.5". There is still a lot of discrepancies between the models on how deep the trough and secondary disturbance will descend south, how quickly the system exits the region, and precipitation totals. Details will be sorted the closer we get. && .AVIATION...Valid through 04/12Z. FEW clouds AOA 20-25k ft AGL streaming across the area moving east through 03/20Z. After 03/20Z clouds become SCT-FEW AOA 13-17k ft AGL with SCT-BKN high clouds AOA 20-25k ft AGL. Slight chances for fog to develop reducing visibility down to 2-3 SM in the Sulfur Springs valley (including KDUG) and Gila River Valley (including KSAD) from 03/12Z through 03/17Z. SFC winds variable and less than 10 kts through the valid period. Aviation discussion not updated for TAF Amendments. && .FIRE WEATHER... Dry Conditions are expected to prevail through Monday. A storm system will move in Tuesday night into Wednesday, perhaps even lingering into Thursday with another round of valley rain and mountain snow. Winds will mainly be less than 15 mph through the forecast period. Minimum relative humidity values will remain elevated through the upcoming week, ranging from 40-60 percent in the valleys and 60-80 percent in the mountains this afternoon, lowering to 30-50 percent in the valleys and 40-60 percent in the mountains Saturday through Monday then increasing Tuesday to 35-45 percent in the valleys 50-60 percent in the mountains. Temperatures will mostly be above normal levels through Sunday, then near normal early next week and finally cooling to below normal levels mid to late next week. && && .TWC WATCHES/WARNINGS/ADVISORIES... None. && $$ Malarkey Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson