Snowmelt runoff from the anomalous amounts of snow over the Arizona high terrain led to continued elevated flows in the Salt and Verde River watersheds. Dam releases being conducted in these watersheds to deal with the abnormal runoff led to continued downstream impacts along the Salt and Gila Rivers, which initially began in March.
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 PSR wrote it up.
Snowmelt runoff from the anomalous amounts of snow over the Arizona high terrain led to continued elevated flows in the Salt and Verde River watersheds. Dam releases being conducted in these watersheds to deal with the abnormal runoff led to continued downstream impacts along the Salt and Gila Rivers, which initially began in March. Continued releases from Granite Reef Dam allowed for elevated flows to persist in the normally dry Salt River with multiple unbridged river crossings remaining closed due to flooding. The heightened flows in the Salt River led to the fatalities of two men who were caught in an undercurrent while paddle boarding down the river. Releases from Granite Reef Dam were significantly reduced by the end of April as runoff into the watersheds decreased. Flow in the Salt and Gila Rivers continued to travel downstream to Painted Rock Dam. Releases from this dam led to elevated flows traveling down the Gila River into Yuma County, leading to numerous additional closures of unbridged river crossings. Elevated flows in the Salt and Gila Rivers allowed for impacts to persist into the month of May.
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 Phoenix, AZ wrote its last area forecast discussion before the first event at Mar 31, 10:20 PM MST, 1 hour 40 minutes earlier.
Area Forecast Discussion National Weather Service Phoenix AZ 1020 PM MST Fri Mar 31 2023 .UPDATE...06Z Aviation Discussion. && .SYNOPSIS... Temperatures will continue to warm through the weekend reaching near to slightly above normal levels over the weekend. Another storm system moving through intermountain West will result in a period of gusty winds Monday followed by a return to cooler conditions during the middle of next week. A warming trend will follow through the end of the week though temperatures will likely remain several degrees below normal. && .DISCUSSION... As a deep PV anomaly ejects into the central Conus spurring a severe weather outbreak across the mid Mississippi River Valley, steady height rises over the SW Conus will translate into a warming trend through the weekend. The only feature of note would be an innocuous vorticity center traversing the region Saturday night. Other than injecting a period of thicker high clouds into the area, no impacts to sensible weather should be expected, and temperatures will continue to warm behind this feature Sunday. Recent NBM iterations continue to highlight a tight inter-quartile range resulting in excellent forecast confidence of high temperatures in lower elevation communities reaching the lower/mid 80s. The first vestiges of an approaching wave intensifying towards the Great Basin will be felt Sunday afternoon/evening in the form of strengthening winds across SE California/SW Arizona. Seasonally deep mixing will begin to tap some of the higher momentum air aloft, however speeds should not become unusual strong for mid spring. However, as the trough digs further southeast Monday developing a deeper anomaly, tightened baroclinicity and a stronger jet core will intensify and align closer to the forecast area. NAEFS wind percentiles are now tipping closer to the 95th percentile over much of the CWA with more rare percentages into the four corners. Correspondingly, ECMWF Wind Gust EFIs have been steadily increasing and with widespread values of 60-80 percent; and there is a 60 percent chance of seeing 35-45 mph gusts late Monday afternoon and early evening across much of the area (highest probabilities in proximity of higher terrain features). Thus, probabilities favor some extent of advisories for Monday afternoon will be issued over the weekend. Given the mostly overland trajectory and northward placement of the cold core, virtually no ensemble solution suggests any rainfall chance with this system. The primary PV anomaly should pivot eastward Tuesday dragging a cold front and sharp drop in temperatures through the region. However, there is sufficient evidence suggesting that mean longwave troughing and weak negative height anomalies will be maintained over the Great Basin through the remainder of the week resulting in only a gradual, modest warming trend. There are even a handful of deterministic and ensemble members indicating development of a cutoff/closed low pressure system in the eastern Pacific next weekend, capable of tapping into deeper subtropical moisture and possibly increasing rain chances. && .AVIATION...Updated at 0520Z. South-central Arizona including KPHX, KIWA, KSDL, KDVT; and Southeast California/Southwest Arizona including KIPL and KBLH: No aviation concerns are expected throughout the forecast period as tranquil conditions prevail. Winds will favor a light and diurnal pattern through tomorrow evening with occasional periods of variability. Lingering high clouds will clear out in the coming hours as FEW to SCT mid level clouds pass through the region overnight into tomorrow morning. Clear skies will follow for the rest of the day tomorrow. && .FIRE WEATHER... Weak high pressure will build northward, generally resulting in mostly clear skies and light winds through Saturday. A warming and drying trend is also expected, though temperatures will remain below normal. Min RHs will likely drop to around 10 percent Saturday afternoon while winds will top out at 10-15 mph. Early next week, a period of windy conditions is likely as a low pressure system moves through the Great Basin and Desert Southwest. A return to well below normal temperatures is anticipated Tuesday. && .HYDROLOGY... Verde River: Bartlett Dam releases continue to decrease to near 2000 cfs. However, water lingering in the channel and backed up from increased flow near the confluence of the Salt River is causing river stages to remain elevated. These river levels along with debris and erratic currents could still be dangerous for recreational interests, and the flood warning has been extended through Monday. Lower Salt: Water releases around 6500 cfs from Lake Roosevelt have necessitated increased downstream releases at Stewart Mountain Dam (~7000 cfs) and Granite Reef Dam (~12500 cfs). Recreation areas along the Salt river remain dangerous, and several are closed due to elevated water levels, erratic currents, and debris carried from upstream. In addition, numerous roads built into the river channel continue to be closed around the Phoenix metro. Gila: Upstream water releases on the Salt River continue to spill into the Gila basin pooling behind Painted Rock Dam. USGS data below Painted Rock Dam continues to show modest increases in depth and release volume. These releases have the potential to flood multiple unbridged river crossings and low lying farm fields. High uncertainty persists regarding the potential for any downstream impacts into Yuma County. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && DISCUSSION...18/Hirsch AVIATION...Leffel FIRE WEATHER...Hirsch HYDROLOGY...18
The national radar mosaic for the moment the first event began.
7 flood. Local standard time, as filed.
According to the Maricopa County DOT, McKellips Road between Alma School Road and SR 202 remained closed due to flooding from the Salt River beginning on March 7th and continuing through April. Timing based on water releases from Granite Reef Dam.
According to MCDOT, the unbridged Salt River crossing along 67th Avenue between Broadway Road and Southern Avenue was closed due to flooding beginning on March 12th and continuing into April. End timing estimated based on upstream FCDMC stream gauge at 51st Avenue.
According to MCDOT, the unbridged Gila River crossing along El Mirage Road between Southern Avenue and Indian Springs Road was closed due to flooding beginning on March 14th and continuing into April. End timing based on upstream FCDMC stream gauge along the Gila River at 116th Avenue.
According to MCDOT, the unbridged Salt River crossing along Gilbert Road between Thomas Road and SR 87 was closed due to flooding beginning on March 14th and continuing into April. The unbridged Gilbert Road crossing sustained heavy damage due to the high flows in the river, keeping the road closed after waters had receded. End timing based on water releases from Granite Reef Dam.
Two men paddle boarding down the Salt River were caught in an undercurrent near 19th Avenue and Broadway on the 9th. They became stuck in the undercurrent around 1000MST and began yelling for help before disappearing under the water. The bodies of the two men were recovered about a week later on the 15th and 16th. Flow in the Salt River was unusually high at the time due to continued upstream releases from Granite Reef Dam. Start time based on continued releases from Granite Reef Dam.
Water being released from Painted Rock Dam traveled down the Gila River, flooding several low water crossings between the dam and the Yuma County line. This led to the closures of Poco Dinero Road between Painted Rock Dam Road and Saddle Road as well as Rocky Point Road between Hyder Road and Painted Rock Dam Road.
Water being released from Painted Rock Dam continued to travel down the Gila River through Yuma County, flooding numerous unbridged river crossings. According to the Yuma County Sheriff's Office, numerous unbridged roads across the Gila River were closed due to flooding going into the last week of April. These road closures persisted into the month of May as elevated flows continued in the Gila River. The USGS gauge along the Gila River near Dateland show the gauge climbing above action stage (8 feet) on April 22nd. By April 30th, the USGS gauge along the Gila River near Dome began to respond as flow in the river continued to gradually travel downstream.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Flood, Maricopa | 2023-04-09 | 38 | Male | In Water | Direct |
| Flood, Maricopa | 2023-04-09 | 38 | Male | In Water | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2023Every state in 2023This day in weather historyWarnings in Arizona, April 2023
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: 1095857, 1095858, 1095860, 1095867, 1095873, 1095876, 1096363.