Area Forecast Discussion
Issued by NWS Tucson, AZ
Issued by NWS Tucson, AZ
097 FXUS65 KTWC 192200 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 300 PM MST Thu Sep 19 2024 .SYNOPSIS...Breezy and dry conditions with temperatures near seasonal normal through the start of the weekend. Temperatures will warm to above normal on Sunday and into the new week. && .DISCUSSION...The synoptic pattern early this afternoon was characterized by an upper level trough seen on water vapor imagery along the coast of central California. A narrow band of Cirrus clouds has set up across southeast Arizona oriented from southwest to northeast from a Sells-Tucson-Safford line with mostly sunny skies elsewhere. The continued troughiness has resulted in high temperatures cooling to near normal this week with high temperatures forecasted to dip below normal through Saturday with the next trough incoming. Surface winds will increase tomorrow with a tightening gradient. Not much in the way of moisture will be drawn up into this system resulting in continued dry weather through the weekend. As the aforementioned trough exits the region it will gradually be replaced by a growing ridge of high pressure. Consequently, high temperatures will gradually rise above normal next week with lighter wind speeds. There is growing likelihood of reaching 100 degrees or hotter from the Tucson Metro westward next week. The latest NBM probabilities of reaching 100 degrees or hotter in Tucson are around 40% Thursday, 45% Friday, and 55% Saturday. Climatologically, daily high temperatures for Tucson during this same timeframe should be around 92 degrees which would put Tucson running around 6-8 degrees above normal for this time of year. && .AVIATION...Valid through 21/00Z. SKC-FEW high clouds at or around 20k ft AGL through the valid forecast period. SFC winds SLY to SWLY this afternoon with speeds around 10-15 kts and occasional gusts to 20 kts through 20/04Z becoming light and variable thereafter. Tomorrow, SWLY winds pick up again after 20/17Z with increased speeds to 12-18 kts with occasional gusts to around 30 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Dry conditions with temperatures within a few degrees of normal through Saturday. 20-foot winds will be southerly- southwesterly 10 to 15 mph with gusts up to around 25 through the rest of the week. Stronger breezes can be expected on Friday afternoon, especially south and east of Tucson. Min RHs will generally be 15 to 20 percent in the lower locations and 20 to 30 percent in the higher locations. Starting Sunday, high pressure ridge will bring warmer temperatures and lighter winds through the first half of the new week. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ DVS Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson