An unusual early June scenario occurred as a cutoff upper level low off the California coast interacted with residual tropical moisture brought up into Arizona from what was once Tropical Storm Alvin. Moisture combine with the low pressure system to trigger thunderstorms over northern Arizona, with some storms training in the same spot for long periods of time.
Every event with a place to put it. 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.
An unusual early June scenario occurred as a cutoff upper level low off the California coast interacted with residual tropical moisture brought up into Arizona from what was once Tropical Storm Alvin. Moisture combine with the low pressure system to trigger thunderstorms over northern Arizona, with some storms training in the same spot for long periods of time. This led to areas of flash flooding on the Havasupai Reservation and portions of the Grand Canyon.
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 Jun 3, 5:10 PM MST, 30 minutes earlier.
Area Forecast Discussion National Weather Service Flagstaff AZ Issued by National Weather Service Tucson AZ 510 PM MST Tue Jun 3 2025 .SYNOPSIS...Scattered showers and thunderstorms will continue the rest of this afternoon and into tonight. A brief lull in shower activity will occur Wednesday morning but showers and thunderstorms will redevelop Wednesday afternoon. A slight chance of showers and thunderstorms will continue along the Utah/Arizona border on Thursday with the rest of the state beginning to dry out. Warmer and drier conditions return Friday through the weekend. && .DISCUSSION...Scattered thunderstorms are developing over the area and will become more numerous this afternoon. These storms could have more staying power than usual and last late into the night as dynamics from the Low approaching from the California coast provides extra lift that usually would be lost when we lose daylight. A FLOOD WATCH for flash flooding is now in effect for the northwestern part of the state and will continue until 5pm on Wednesday. Reason for the long duration of the event being even though we may see a brief lull in activity on Wednesday morning, daytime heating along with the weakening Low moving across the area providing extra lift will allow another round of showers and storms to initiate around noon Wednesday and continue through the evening. As with most convective events, rainfall amounts will be locally heavy under storms that do develop. By Thursday this Low will have opened up into a weak wave and departed the area but another shortwave brushing by to the north of us could trigger a few isolated showers or storms mainly along the Arizona/Utah border, but potentially as far south as the Grand Canyon, with the rest of Arizona drying out and beginning to warm back up closer to early June averages. By Friday and lasting through the weekend, high pressure begins to rebuild from the south which will dry the rest of the state out and allow temperatures to climb to seasonal or slightly above seasonal averages. && .AVIATION...Wednesday 04/00Z through Thursday 05/00Z...SCT to NMRS SHRA/TSRA this evening, decreasing after midnight. A few of the stronger storms could produce MVFR/IFR in +RA, hail, and gusty winds. Outside of storm activity, winds W-SW at 5-15 kts. SCT to NMRS storms developing after 17Z on Wednesday with MVFR/IFR in +RA, hail, and gusty winds with the stronger storms. OUTLOOK...Thursday 05/00Z through Saturday 07/00Z...Scattered SHRA/TSRA decreasing after 00Z on Thursday (Wed eve). Local MVFR/IFR possible in stronger storms with otherwise mostly VFR. A 20-30% chance of -TSRA continues from KGCN northward from 00Z Thurs - 00Z Fri. && .FIRE WEATHER...Wednesday and Thursday, scattered showers and thunderstorms continue on Wednesday, with only a few isolated showers or storms along the Utah/Arizona border Thursday. A few stronger storms could produce hail, heavy rain and erratic wind gusts. Otherwise, expect daytime winds from the west to southwest at 10-20 mph. Friday through Sunday...Dry and warmer weather returns Friday into the weekend with decreasing humidity each day and temperatures climbing above average by the end of the weekend. Winds generally west to southwest at 10-15 mph. && .FGZ WATCHES/WARNINGS/ADVISORIES... Flood Watch through Wednesday afternoon for AZZ004-006>008-012- 015-016-037-038. && PUBLIC...Bernhart AVIATION...BAK FIRE WEATHER...Bernhart For Northern Arizona weather information visit weather.gov/flagstaff
Special Weather Statement
National Weather Service Flagstaff AZ
Issued by National Weather Service Las Vegas NV
115 PM MST Tue Jun 3 2025
AZZ012-015-032045-
Little Colorado River Valley in Coconino County-Western Mogollon Rim-
115 PM MST Tue Jun 3 2025
...A STRONG THUNDERSTORM WILL IMPACT EAST CENTRAL COCONINO COUNTY
INCLUDING WINONA AND INTERSTATE 40 THROUGH 145 PM MST...
At 114 PM MST, Doppler radar was tracking a strong thunderstorm over
Winona, or 11 miles east of Flagstaff, moving east at 20 mph.
HAZARD...Wind gusts up to 40 mph and penny size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
Angell, Canyon Padre Bridge, Twin Arrows, and Winona.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 3513 11146 3525 11143 3524 11120 3507 11122
TIME...MOT...LOC 2014Z 280DEG 18KT 3520 11143
MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH
JJSpecial Weather Statement
National Weather Service Flagstaff AZ
Issued by National Weather Service Las Vegas NV
157 PM MST Tue Jun 3 2025
AZZ012-013-032130-
Little Colorado River Valley in Navajo County-Little Colorado River
Valley in Coconino County-
157 PM MST Tue Jun 3 2025
...A STRONG THUNDERSTORM WILL IMPACT INTERSTATE 40 IN SOUTHWESTERN
NAVAJO AND SOUTHEASTERN COCONINO COUNTIES THROUGH 230 PM MST...
At 153 PM MST, Doppler radar was tracking a strong thunderstorm near
Winslow Airport, or near Winslow, moving east at 25 mph.
HAZARD...Wind gusts up to 40 mph and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
Winslow, Winslow Airport, Homolovi State Park, Clear Creek Reservoir,
Bushman Acres, and Homolovi State Park Campground.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 3500 11093 3515 11089 3514 11056 3491 11058
TIME...MOT...LOC 2053Z 284DEG 21KT 3506 11082
MAX HAIL SIZE...0.88 IN
MAX WIND GUST...40 MPH
JJThe Cedar City radar (KICX), 151 km away, was scanning. The volume nearest the first event began at 00:39 UTC.
2 flash flood. Local standard time, as filed.
Tribal officials from the Havasupai Reservation reported that trails were flooded and impassable along Havasu Creek causing hikers to be stranded. All hikers were later accounted for, no injuries or fatalities. Some structures in the village of Supai were also impacted.
A USGS Stream Gage indicated a rise of over 6 feet in Kanab Creek due to heavy rain upstream.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2025Every state in 2025This day in weather historyWarnings in Arizona, June 2025
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: 1254841, 1254837.