A deep upper level low moved across The Great Basin and through Arizona. This system was anomalously strong for the time of year and is quite cold aloft.
Every event with a place to put it; 8 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS FGZ wrote it up.
A deep upper level low moved across The Great Basin and through Arizona. This system was anomalously strong for the time of year and is quite cold aloft. The pressure gradient tightened up and resulted in extremely gusty and strong winds. While most areas experienced wind gusts around 40-50 MPH with some areas had gusts of 55-65 MPH. The highest gusts were downwind of the higher terrain.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Flagstaff, AZ wrote its last area forecast discussion before the first event at May 5, 10:38 AM MST, 52 minutes earlier.
Area Forecast Discussion National Weather Service Flagstaff AZ 1038 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 05/18Z through Monday 06/18Z...Expect very strong winds and generally VFR conditions through the TAF period, with the exception of periods of MVFR ceilings/visibilities between 21Z-06Z due to -SHRA/SHSN along and north of I-40 as a cold front moves west to east across the area. Isolated MVFR conditions from blowing dust near KINW, KSJN, and KRQE will be possible due to the 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 06/18Z through Wednesday 08/18Z...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-KFLG-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...BAK FIRE WEATHER...BAK For Northern Arizona weather information visit weather.gov/flagstaff
The national radar mosaic for the moment the first event began.
8 high wind. Local standard time, as filed.
A wind sensor at Highway 260 (mile post 378) and Highway 273 reported a peak wind gust of 62 MPH at 413 PM. The sustained wind was above 40 MPH and/or wind gusts were above 58 MPH between1130 PM and 430 PM.
The Flagstaff Airport had a peak wind gust of 63 MPH at 1159 AM. The wind gusts were above 58 MPH from around 1130 AM to around Noon.
The Mogollon Rim Airpark measured a peak wind gust of 59 MPH at 335 PM. The Mesonet station near Heber measure a peak wind gust of 63 MPH. The RAWS station at Limestone Canyon had a peak wind gust of 63 MPH at 124 PM. Wind gusts at Limestone were 58 MPH or higher from around 100 PM to 300 PM.
The peak wind gust at the Winslow Airport was 64 MPH at 506 PM. Wind gust of 58 MPH or higher occurred between 150 PM and 510 PM. The KINW airport is less than ten miles into the next county. The peak wind gust at Two Guns (ADOT sensor) along I-40 was 73 MPH at 603 PM. Wind gusts were 58 MPH or higher from around 200 PM to 700 PM.
The Taylor Airport had a peak wind gust of 58 MPH at 415 PM. The sustained wind was 40 MPH or higher a few times between 250 PM and 540 PM. A wind sensor along I-40 at the Little Colorado River measured a wind gust of 61 MPH at 433 PM. The peak wind gust at the Winslow Airport was 64 MPH at 506 PM. Wind gust of 58 MPH or higher occurred between 150 PM and 510 PM.
The Four Springs RAWS on top of the Vermillion Cliffs measured a peak wind gust of 59 MPH at 319 PM.
The Window Rock Airport measured a peak wind gust of 62 MPH at 319 PM.
The peak wind gust at the Springerville Airport was 71 MPH at 830 PM. The wind gusted to at least 58 MPH at time between 420 PM and 1000 PM. The sustained winds remained above 40 MPH the entire time between 645 PM and 1000 PM.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2024Every state in 2024This day in weather historyWarnings in Arizona, May 2024
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1182869, 1182901, 1182854, 1182904, 1182842, 1182856, 1182888, 1182922.