Forecast Discussion
000 FXUS65 KTWC 282103 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 203 PM MST Tue Nov 28 2023 .SYNOPSIS... A cooling trend begins on Thursday due to an active pattern brings valley rain and mountain snow Thursday into Saturday. && .DISCUSSION...The ridge that is currently keeping us warm and dry will continue to linger through tomorrow before giving way to the incoming system that is currently spinning in the Pacific Ocean off the coast of California. The upper level low will work its way to the area late Wednesday to early Thursday bringing the first round of chances for mountain snow and valley rain. A second round of precipitation chances begins Thursday night into Friday night as an inland shortwave comes in. This second system continues to have the higher amounts of precipitation, however the NBM has backed off in terms of storm rain and snow totals, which is consistent with this drier pattern. Timing has remained fairly the same with these two rounds as well. Overall, both rounds remain below any Winter Weather Advisory criteria with the main impacts of the systems being breezy west to northwest winds, fairly light (up to 5 inches in the White Mountains and up to 3 inches on Mt. Lemon) accumulation of snow in elevations higher than 6500 feet, and slick roadways in the valleys. This second system brings cooler minimum temperatures Sunday and Monday mornings. The troughiness begins to trek eastward out of the area on Saturday and leaves a building ridge helping to rebound the high temperatures to near to above normal for the begining of next week. && .AVIATION...Valid through 30/00Z. FEW-SCT clouds 8-12K ft MSL, SCT clouds AOA 20k ft MSL. SFC winds will be generally southeasterly and less than 12 kts through Wednesday morning then becoming west to southwest 8-14 kts AFT 29/19Z. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Dry with temperatures a few degrees above average again Wednesday with light 20ft winds. A two-part storm system will bring cooler temperatures, breezy winds, and a chance of valley showers and mountain snow showers at times Wednesday night through Friday night. Some light snow accumulations are expected above about 6,500 ft over the Sky Islands north and east of Tucson and the White Mountains Wednesday night into early Thursday morning and again Thursday night through Friday night. Clearing and colder than normal Saturday through Monday. && .TWC WATCHES/WARNINGS/ADVISORIES... None. && $$ Tetrault/Cerniglia Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
NWS TWC Office Area Forecast Discussion