textproduct: NWS Tucson Arizona

SYNOPSIS

Dry and hot conditions across southeastern Arizona through the coming week as high temperatures remain several degrees above normal. Temperatures peak this Saturday through Monday, with extreme heat across southeast Arizona and highs 8 to 12 degrees above normal.

DISCUSSION

High pressure aloft will dominate the weather across southeast Arizona through at least early next week. High temperatures will be 2-5 degrees above normal through Friday, rising to 8-12 degrees above normal Sunday and Monday as the high becomes centered nearly overhead. Minor HeatRisk (with small pockets of Moderate) will continue across southeast Arizona through Friday, Moderate HeatRisk (with pockets of Major) on Saturday and then Major HeatRisk Sunday and Monday. NBM probabilities of 110+ degrees this Saturday in Tucson are at 10 percent, with 60+ percent probabilities Sunday and 40 percent on Monday. An Extreme Heat Watch has been issued from Saturday morning through Monday evening for the lower elevations of southeast Arizona. High temperatures lower several degrees mid to late next week as system moves across the Great Basin flattening the upper ridge. However, readings will still be 2-5 degrees above normal next week.

Otherwise, enough mid-level moisture remains in place today across the White Mountains for a slight chance (10-20 percent) of afternoon and early evening mainly dry thunderstorms. Gusty outflow winds and lightning sparked wildfires will be the main threats with any storms that do develop. Breezy west to northwest winds will continue in the upper Gila River valley near Safford today and east of Tucson across portions of Cochise and Graham counties on Thursday. Peak afternoon and early evening wind speeds of 15-20 mph and gusts to around 30 mph are expected, especially on Thursday. The strongest winds will be in the upper Gila River valley near Safford, with the possibility of a few hours of near critical fire weather conditions.

AVIATION

Valid through 12/12Z. SCT clouds AOA 20k ft AGL areawide thru the forecast period. FEW-SCT clouds at 12k-15k ft AGL from KTUS eastward aft 11/15Z. There will be a slight chance of -TSRA in the White Mountains NE of KSAD between 11/18Z and 12/03Z. SFC wind generally less than 12 kts and variable in direction thru 11/18Z and again aft 12/03Z. WLY/NWLY SFC wind between 11/18Z and 11/03Z at 8-13 kts west of a KTUS to KOLS line, with wind speeds of 12-17 kts and gusts to 20-27 kts east of this line in the vicinity of KDUG, KALK and especially KSAD. Aviation discussion not updated for TAF amendments.

FIRE WEATHER

Dry conditions are expected across most of southeast Arizona through early next week, with just a slight chance (10-20 percent) of afternoon/early evening mainly dry thunderstorms in the White Mountains today. Generally single digit min RH values in the valleys, with mountain locations in the 10-20 percent range. 20-foot winds will be 15 mph or less from Tucson westward, with occasional afternoon/early evening gusts to around 25 mph due to the strong surface heating. East of Tucson, breezy afternoon/early evening 20- foot winds are expected across portions of Cochise and Graham counties through Thursday, with peak wind speeds of 15-20 mph and gusts to around 30 mph. The strongest winds will be in the upper Gila River valley near Safford, with the possibility of a few hours of near critical fire weather conditions.

TWC WATCHES/WARNINGS/ADVISORIES

Extreme Heat Watch from Saturday morning through Monday evening for AZZ501>509.