Area Forecast Discussion
Issued by NWS Tucson, AZ
Issued by NWS Tucson, AZ
851 FXUS65 KTWC 161036 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 336 AM MST Sun Nov 16 2025 .SYNOPSIS...An active weather pattern is in store for Southeast Arizona over the next week as a series of low pressure systems move across the region. These systems will bring cooler temperatures, a chance of precipitation and breezy winds at times. Afternoon temperatures will be a few degrees below normal today, with another push of cold air resulting in afternoon temperatures 10 to 13 degrees below normal by the middle of next week. && .DISCUSSION...The upper pattern this morning is defined by a strong cutoff-low begining to eject NNE through the Southern California Bight and its kicker trough, currently off the coast of British Columbia, moving SE. The latest GOES precipitable water imagery indicated a shrinking subtropical moisture plume (between 1.15-1.25 inches PWAT) along the southeast periphery of the cutoff-low, extending up the Gulf of California and into central Arizona, where a maxima of PWAT near 1.50 inches resides. The bulk of the lift/forcing associated with this ejecting feature will continue to remain across southern California and the NW half of Arizona. The upper trough axis and associated lower-level cold front will track across SW Arizona into central Arizona during the day today. Marginal moisture convergence along the frontal boundary this morning, with the latest satellite imagery indicating some enhancement of clouds across western Pima county early this morning, with a band of showers extending northward across western Maricopa county. The most recent HRRR run suggests that this band of showers will expand along the cold front over central Pima county before daybreak, slowly make its way ENE to the Tucson Metro Area by 9-11 AM, and to Safford by 1-3 PM. Rainfall amounts will generally be light, with the valleys expected to receive between a few hundredths of an inch up to a tenth inch, and 0.15-0.40 inches in the higher terrain/mountains. Precipitation will fall as rain as snow levels will be around 10k feet during the day, but a mix of rain/snow may be possible on the mountain tops as the colder air filters into the area behind the front and snow levels drop to near 9000 feet this afternoon. This system will depart Southeast Arizona this evening, leaving chilly temperatures in its wake Monday morning. The combination of the cooler airmass, light winds and clearing skies will result in some pockets of fog in the eastern valleys of Cochise county Monday morning, especially the Sulphur Springs Valley and southern portions of the San Pedro River Valley. Otherwise, the upstream trough responsible for ejecting the cutoff- low will eventually take up residence in the wake of its predecessor in the mean trough to our west. There is some variance with the ensemble members on the location of the upper low Tuesday afternoon near southern California. The location of this feature may not be that important as the upper low is progged to pivot with a more neutral orientation, which is more susceptible to swing east through our neck of the woods Wednesday. The only concern I have is if this feature continues to move farther south during the pivot, this would push the best dynamics across northern Sonora Mexico. In any event, this system will be colder, with a better chance for valley rain and mountain snow above 7000 feet. As mentioned in the previous forecast discussion, high temperatures will lower to 10-13 degrees below normal on Wednesday, with highs in the lower to mid 60s from Tucson westward and in the mid 50s to around 60 degrees in the lower elevations of Santa Cruz, Cochise, Graham and Greenlee counties. Breezy winds are also expected Tuesday and Wednesday, especially to the east/southeast of Tucson, with south-southwest winds of 15-20 mph and gusts to around 30 mph. Colder morning low temperatures are forecasted behind the system Thursday and Friday mornings and more widespread freezing low temperatures are likely over portions of eastern Santa Cruz, southwest Graham and portions of Cochise counties. Overall, minor to moderate impacts are expected with this next system. && .AVIATION...Valid through 17/12Z. SCT-BKN clouds at 7k-10k ft AGL areawide with ISOLD-SCT -SHRA and a slight chance of -TSRA thru 17/00Z, then cloud cover tapering off overnight. SFC wind less than 10 kts and variable in direction through 16/16Z, increasing to SLY/SWLY SFC wind with speeds of 15-20 kts and gusts to 25-30 kts by 16/19Z, persisting thru 17/03Z, then SFC wind less than 10 kts and variable in direction overnight. Patchy fog may develop across the Sulphur Springs valley and southern San Pedro River Valley Monday morning resulting in localized VSBY 1-3SM BR, potentially impacting KDUG, KFHU and KALK. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A storm system will move across the area today, with showers spreading from west to east across southeast Arizona during the day. This system will also bring a slight chance of thunderstorms and cooler temperatures. Breezy southwest winds of 15-25 mph with gusts to 30-35 mph are expected. Another system is then expected to move into the area Tuesday and especially Wednesday of next week. This system will bring another round of precipitation across Southeast Arizona, well below normal temperatures and breezy south to southwest winds. RH values will be on the increase, with Min RH values well above critical levels over the next week (30-40 percent in the valleys and 50-60+ percent in the mountains). && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson