965 FXUS65 KFGZ 141115 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 415 AM MST Mon Apr 14 2025 .SYNOPSIS...A gradual cooling trend is expected this week with a chance of showers Monday night and Tuesday and again Thursday night into the weekend. Breezy to windy each day starting Tuesday. && .DISCUSSION...A fast moving high pressure system will move across Arizona today. Look for another warm day with high temperatures around 10 degrees above normal. Pressure gradients have weakened with the high positioned directly over Arizona so winds are forecast to be light and variable. High level subtropical moisture will continue to stream across Arizona so anticipate, much like the past couple of days, periods of sun and clouds. Tonight and Tuesday...A fast moving shortwave trough will move across northern Arizona. This system will draw just enough moisture northward for a slight chance of showers tonight with slightly better slight chances on Tuesday, mainly north of the Interstate-40 corridor. We could even see some late morning and afternoon thunder on Tuesday with daytime heating destabilizing the atmosphere. Otherwise, only slightly cooler as the trough moves across and stronger southwest breezes generally at 10 to 20 mph but with a few gusts over 30 mph over east central Arizona. Wednesday and Thursday...Generally cooler and turning windy on Thursday as a longwave trough begins to develop over the western states. Pressure gradients will strengthen under the influence of the trough with southwest winds at 10 to 20 mph with more widespread 30 mph gusts on Wednesday. By Thursday, as gradients strengthen further, look for sustained south to southwest winds at 15 to 25 mph with gusts of 30 to 45 mph. The higher numbers will be located from the Mogollon Rim northward. From Friday onward...The longwave trough will swing across Arizona. There remains a variety of solutions with some models forming a closed-low over Arizona with and extended period of showers possible. Other solutions bring the bulk of the precipitation with a passing cold front which would result in a shorter more intense period of showers. Our confidence has grown in terms of the end of the week shower threat but the exact timing remains a bit fuzzy. The two solutions also present differing snow level possibilities but for now the best estimate is that any accumulating snow will be confined to elevations at or above 6500-7000 feet. Like all systems this time of year, if the shower chances develop, isolated thunder should be anticipated. && .AVIATION...Monday 14/12Z through Tuesday 15/12Z...VFR conditions expected to persist under high clouds. Light and variable winds expected through the period, generally less than 10-15 kts. OUTLOOK...Tuesday 15/12Z through Thursday 17/12Z...VFR conditions will continue, but brief MVFR conditions are possible 12Z Tuesday through 00Z Wednesday from -SHRA and VCTS. Greatest chances for showers/storms will be along and north of I-40. Winds will mostly be S-SW 15-25 kts each afternoon, becoming light and variable overnight. Gusty and erratic winds possible near showers/storms. && .FIRE WEATHER...Monday and Tuesday...Above normal temperatures will remain each afternoon, despite a slight cooling trend. Dry conditions expected today, with slight chances (10-25%) for showers/thunderstorms Tuesday morning and afternoon. Greatest chances for precipitation will be along/north of I-40. Light and variable winds forecast for Monday, becoming southerly 10-20 mph on Tuesday. Wednesday through Friday...Temperatures will dramatically cool through the end of the week, landing 10-20 degrees below normal by Friday. Minimum RH values look to remain 20-25% or less Wednesday and Thursday, before rain/high elevation snow chances return on Friday. Look for southwest winds 10-25 mph each afternoon, with gusts 30-40 mph on Thursday. && .FGZ WATCHES/WARNINGS/ADVISORIES...None. && $$ PUBLIC...McCollum AVIATION...Konieczny FIRE WEATHER...Konieczny For Northern Arizona weather information visit weather.gov/flagstaff