Area Forecast Discussion
Issued by NWS Flagstaff, AZ
Issued by NWS Flagstaff, AZ
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149 FXUS65 KFGZ 051516 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 816 AM MST Sun May 5 2024 .SYNOPSIS...A strong low pressure will cross the region today bringing strong, gusty winds and isolated to scattered showers. Winds will decrease late tonight but remain breezy through much of the week. Temperatures will remain cool and conditions will remain dry through the week as several troughs cross through the region. && .UPDATE...The current forecast is on track. Strong winds will be observed across much of northern Arizona today into this evening. In addition, some shower activity will move in later this afternoon with the best chances toward the Utah border. && .PREV DISCUSSION /416 AM MST/...A deep upper level low will dig southward, crossing the Great Basin and moving through our region today. This system is anomalously strong for this time of year and is quite cold aloft. There will be several things to discuss with this low so we will break it down by hazard. First, the pressure gradient tightens up and as a result we will see extremely gusty and strong winds, especially as we move through the day. While most areas will see winds gusting up to around 40-50 mph, there will be areas of 55-65 mph, mainly to the north and east of the Mogollon Rim. Highest gusts are likely to be downwind of the higher terrain so be prepared for strong winds, especially if out and about today. No changes were made to the current headlines as they look well placed based on the latest guidance and expected wind gusts. Second, guidance continues to increase the precipitation chances across the region as the low passes to the north. While we still aren`t expecting blockbuster amounts of precipitation, it is looking more likely that we will see some showers as far south as the I-40 corridor through this afternoon. Additionally, as the low pushes to the east, there will be a good amount of cold air aloft. Even though we have relatively warm temperatures ahead of the this system, the cold air will have little preventing it from working its way down to the surface. This means there is a good chance that the rain will changeover to snow in some locations. Snow levels that start off above 8500 feet will drop as the associated cold front moves through and quickly fall to 5500-6500 feet. While accumulations are not likely in most locations, could see a few inches accumulate in some of the higher elevations. Most likely areas are over the Kaibab Plateau and the San Francisco Peaks. Just don`t be shocked if you see some flakes falling from the sky as we move through this evening. Third, as previously mentioned, there is a good deal of cold air associated with this system. This will result in temperatures falling to below normal. Overnight lows tonight will be quite cold with the typically colder spots dropping down into the low to mid 20s! If you have put any plants out recently, it wouldn`t be a bad idea to bring them indoors or cover them to protect them from the freezing temperatures. Fourth, limited potential for near critical fire weather continues for today. Strong southwest winds and RH values in the 10-20% range are expected but fuels remain marginal, outside of the area around St. Johns, where a Red Flag Warning remains in place. Once the low passes to the east of the region, we will see things dry out rather quickly. However, several troughs will cross the region through the week, keeping temperatures on the cool side and winds breezy each day. No precipitation is expected through the rest of the week. With the strong winds and dry conditions continuing through the week, we will see afternoon RH values drop in the 5-15% range. While this raises the potential for near critical fire weather concerns over the course of the week, it will be the fuels that may end up being the limiting factor. && .AVIATION...Sunday 05/12Z through Monday 06/12Z...VFR conditions will mostly persist through the TAF period. Brief periods MVFR ceilings/visibilities will be possible between 18Z-06Z due to -SHRA/SHSN along and north of I-40. Also, isolated MVFR conditions from blowing dust near KINW, KSJN, and KRQE will be possible from high winds. Look for SW winds 20-35 kts, gusting 40-55 kts. Localized areas may see gusts up to 65 kts. Winds will decrease west to east after 04Z. OUTLOOK...Monday 06/12Z through Wednesday 08/12Z...VFR conditions expected through the outlook period. Look for west winds 15-25 kts, gusting 30-40 kts on both Monday and Tuesday afternoon. Strongest winds will be along and east of a KGCN-KKoniecznyFLG-KSOW line. && .FIRE WEATHER...Sunday and Monday...Southwest winds will quickly ramp up today, with sustained speeds between 25-35 mph gusting 40-55 mph. Localized areas downslope of terrain may see gusts upwards of 60 mph. Red Flag conditions expected for portions of Apache County this afternoon. Rain and snow chances likely across higher terrain north of I-40 today. Winds will become lighter on Monday out of the west, gusting 20-30 mph. Tuesday through Thursday...Breezy west winds, especially along AZ/NM border, stick around for Tuesday, becoming lighter west through north winds Wednesday and Thursday. Dry conditions will persist each day along with temperatures a few degrees below normal. && .FGZ WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 9 PM MST /10 PM MDT/ this evening for AZZ004>007-009>017-039-040. Wind Advisory until 9 PM MST this evening for AZZ008. Red Flag Warning until 9 PM MST this evening for AZZ114. && $$ PUBLIC...McCollum/Meola AVIATION...Konieczny FIRE WEATHER...Konieczny For Northern Arizona weather information visit weather.gov/flagstaff