Area Forecast Discussion
Issued by NWS Tucson, AZ
Issued by NWS Tucson, AZ
761 FXUS65 KTWC 091022 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 322 AM MST Sun Nov 9 2025 .SYNOPSIS... Breezy conditions are expected today and Monday with a slight cool down in Graham, Greenlee, and Cochise counties. Valleys east of Tucson including the Sulphur Springs Valley may see morning lows fall near to below freezing Monday and Tuesday mornings. A low pressure system may impact the region Friday through the next weekend, bringing chances for precipitation, cooler temperatures, and windy conditions. && .DISCUSSION... Water vapor imagery this morning depicts an amplified pattern aloft with a west coast ridge sitting between deep troughs over the eastern Pacific and the central to eastern CONUS. As the trough to the east deepens today a surface pressure gradient will tighten over southeastern Arizona, while cooler air pushes into locations east of Tucson-Nogales. East to southeast winds of 10-20 mph with gusts up to 35 mph will be found in areas exposed to easterly flow, especially through the Gila River Valley. Forecast highs today east of Tucson-Nogales are around 3-6 degrees cooler than yesterday, with little change to the west. This eastern cool- down will also produce a threat of freezing morning lows over the next couple mornings in the normally cooler eastern valleys. With the pressure gradient lingering into Monday morning, surface winds may keep temperatures from dropping too much (though can`t rule out locations sheltered from this wind becoming colder)...but Tuesday morning should see a stronger shot at sub- freezing lows with lighter winds. NBM probabilities of sub- freezing lows in the Sulphur Springs Valley Tuesday morning have risen to around 30-60 percent. If this trend continues a freeze headline will likely be needed. Temperatures return to above normal through the second half of the work week as the upper ridge axis moves east over the region. This ridge will likely keep on moving east to exit as an upstream Pacific trough crosses the west coast by Friday-Saturday. Confidence is increasing in the occurrence of this trough crossing the desert southwest, though there remains moderate discrepancies in guidance regarding timing and strength. There does remain a small subset of ensemble members which keep ridging in place, though most are now favoring a cooler and (relatively) wetter push this weekend into next week. Of the members that bring this trough through, there is also a split between a Friday versus Saturday arrival, with an increasing number of members starting to lean towards a Friday onset. High temperatures may see a good 15 to 20 degree drop with this system, which means this shift in timing has played an impact on forecast highs. Current forecast highs for Friday are now in the upper 60s to mid 70s across desert locations of southeastern Arizona, and may see a further drop as timing is worked out. Highs over 10-15 degrees below normal are possible this weekend in the immediate wake of the trough passage. Rain and high elevation snow chances with increased winds will also be associated with this system, though again with many details to work out in the coming week. && .AVIATION...Valid through 10/12Z. Increasing east to southeasterly surface winds today will become 10-15 kts with gusts to 20 kts, and 15-20 kts with gusts to 30 kts at KSAD. Winds may diminish somewhat this evening but remain increased, especially in areas exposed to east/southeast flow. SKC through the forecast period. && .FIRE WEATHER... Increasing east/southeast winds today, especially in areas exposed to east/southeast flow. 10-20 mph sustained winds with gusts to 35 mph with winds on the stronger side through the Gila River Valley and southern Cochise. Increased winds will last into Monday before diminishing by Monday evening. Minimum relative humidity around 12-22 percent through Thursday. There is increasing confidence in a system impacting the region arriving as early as Friday. Increased winds, cooler temperatures, and chances for precipitation would arrive with this system. && .TWC WATCHES/WARNINGS/ADVISORIES... None. && $$ Public...Edwards Aviation...Edwards Fire Weather....Edwards Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson