An amplified upper level ridge situated over the West Coast allowed for temperatures to warm up above normal and even briefly reach excessive heat conditions across parts of the lower deserts. High temperatures in Phoenix during this time peaked on the 27th at 113 degrees, while low temperatures only fell into the low to mid 80s each night.
Every event with a place to put it; 12 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 PSR wrote it up.
An amplified upper level ridge situated over the West Coast allowed for temperatures to warm up above normal and even briefly reach excessive heat conditions across parts of the lower deserts. High temperatures in Phoenix during this time peaked on the 27th at 113 degrees, while low temperatures only fell into the low to mid 80s each night. According to the Maricopa County Department of Public Health, 17 fatalities occurred due to the heat.
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 Jun 24, 11:03 PM MST, 57 minutes earlier.
Area Forecast Discussion National Weather Service Phoenix AZ 1103 PM MST Thu Jun 24 2021 .UPDATE...Updated Aviation Discussion. && .SYNOPSIS... Isolated showers and a few storms will continue to be possible through this afternoon, but most locations will be dry today. Increasing high pressure and drier conditions starting Friday are expected to push high temperatures back to around 110 degrees across the lower deserts by this weekend. Unsettled weather conditions are likely starting next Monday or Tuesday as increased moisture is likely to bring even better shower and thunderstorm chances. && .DISCUSSION... Scattered convection began early today, around 9 AM, with an isolated storm even developing south of Phoenix near the Table Top Mtns area. Besides other common terrain areas known for convective storm development, like the Kofas in northern Yuma/southern La Paz counties, cumulus elsewhere across the lower deserts have been limited in growth. PWATs are down from yesterday with drier air having worked in aloft under southwesterly flow. The 12Z sounding this morning out of Phoenix featured a few inversions, which may be one of the limiting factors. The sounding out of Phoenix, and 18Z one out of the Yuma Proving Grounds, do feature relatively low convective temperatures and marginal SBCAPE around 500 J/kg, so additional isolated convection may still sprout up across the lower deserts, including Phoenix, through the rest of the afternoon with a few isolated strong storms possible. The most favorable areas for strong storms through the afternoon will be across portions of La Paz county. DCAPE is high around 1500-1800 J/kg, so strong downburst winds will remain the primary threat, but any training of cells tied to terrain features may still produce localized flooding impacts. With convection being primarily surface-based, activity should diminish quickly this evening after sundown. .PREVIOUS DISCUSSION... Friday and Saturday will return to a more typical late June hot and dry pattern with the upper level trough to our west shearing out completely while drifting southeastward through our region on Saturday. The drying trend in combination with typical late June 500mb heights of 586-590dm will lead to warming temperatures through the weekend with forecast highs near normal Friday and then likely around 110 degrees for the Phoenix area and 111-114 degrees across the western deserts for Sunday. These readings for Sunday are borderline high HeatRisk, but will hold off on any Excessive Heat products for now due to the localized risk and the fact the past several NBM model runs has been trending cooler with this next round of heat. Next week is looking more and more interesting with each passing day as confidence is increasing in deep monsoon moisture streaming into the Desert Southwest from the east and south during the first half of next week. Easterly flow is likely to develop on Monday within a highly amplified upper level pattern with a strong ridge center across the Pacific Northwest and a deep trough extending throughout the Plains States. There may even be enough marginal moisture present as early as Sunday to bring some isolated convection across the eastern Arizona high terrain and likely more activity but still limited to the high terrain on Monday. By Tuesday or Wednesday, models indicate at least one inverted trough may progress westward through northern Mexico into southern portions of the Desert Southwest. Even though this favorable monsoon pattern is a bit unusual this early in the season, it is hard to dismiss as models have been consistent in showing this over the past few days. Deep monsoonal moisture for scattered to possibly widespread showers and thunderstorms across much if not all of the area may occur by the middle of next week. && .AVIATION...Updated at 0602Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Light winds will be favored going through the overnight hours with variability in directions. Winds are expected to favor an easterly component overnight with speeds remaining below 8 kts. Westerly winds increase going into early tomorrow afternoon with gusts upwards of 15-20 kts possible. Shower/thunderstorm activity is expected to remain across northern portions of Arizona tomorrow with very little chance of getting an outflow into Phoenix. Otherwise, mostly clear skies will continue aside from a few clouds aoa 10 kft. Southeast California/Southwest Arizona including KIPL and KBLH: No major aviation concerns are expected through the period under mostly clear skies. Winds at KBLH are expected to favor a south to west/southwest component through the next 24 hours, while winds at KIPL favor a west to southwest component through much of the period. Otherwise, skies will generally remain clear aside from a few clouds aoa 10 kft during the afternoon. && .FIRE WEATHER... Sunday through Thursday: Conditions will be warmest and driest Sunday with lower desert highs in the 110-114F range and min RHs around 10-15%. Temperatures trend down toward or below seasonal levels through early next week as the weather pattern shifts and moisture increases into the region. Min RHs gradually climb up to 20-25% by the middle of the week with overnight recoveries rising from 25-35% Monday to 40-55% by the middle of the week. With the increased moisture, rain and storm chances will increase as well, primarily across eastern districts on Monday, possibly as early as Sunday afternoon, likely followed by more widespread activity late in the period. Aside from any thunderstorm outflows next week, winds will follow typical diurnal patterns with afternoon gusts. && .SPOTTER INFORMATION STATEMENT... Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && DISCUSSION...Benedict PREVIOUS DISCUSSION...Kuhlman AVIATION...Smith FIRE WEATHER...Benedict/Kuhlman
The national radar mosaic for the moment the first event began.
8 heat, 4 excessive heat. Local standard time, as filed.
Two direct fatalities were reported by the Maricopa County Department of Public Health, with their details, such as age, gender, circumstances, and exact location unavailable.
One indirect fatality was reported by the Maricopa County Department of Public Health, with their details, such as age, gender, circumstances, and exact location unavailable.
One direct fatality was reported by the Maricopa County Department of Public Health, with their details, such as age, gender, circumstances, and exact location unavailable.
One direct fatality was reported by the Maricopa County Department of Public Health, with their details, such as age, gender, circumstances, and exact location unavailable.
One direct fatality was reported by the Maricopa County Department of Public Health, with their details, such as age, gender, circumstances, and exact location unavailable.
One direct fatality was reported by the Maricopa County Department of Public Health, with their details, such as age, gender, circumstances, and exact location unavailable.
Three indirect fatalities were reported by the Maricopa County Department of Public Health, with their details, such as age, gender, circumstances, and exact location unavailable.
One indirect fatality was reported by the Maricopa County Department of Public Health, with their details, such as age, gender, circumstances, and exact location unavailable.
Two indirect fatalities were reported by the Maricopa County Department of Public Health, with their details, such as age, gender, circumstances, and exact location unavailable.
Four indirect fatalities were reported by the Maricopa County Department of Public Health, with their details, such as age, gender, circumstances, and exact location unavailable.
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 |
|---|---|---|---|---|---|
| Heat, Central Phoenix | 2021-06-25 | Unknown | Direct | ||
| Heat, Central Phoenix | 2021-06-25 | Unknown | Direct | ||
| Heat, Buckeye/Avondale | 2021-06-26 | Unknown | Indirect | ||
| Excessive Heat, Central Phoenix | 2021-06-27 | Unknown | Direct | ||
| Excessive Heat, East Valley | 2021-06-27 | Unknown | Direct | ||
| Heat, East Valley | 2021-06-28 | Unknown | Direct | ||
| Heat, Central Phoenix | 2021-06-29 | Unknown | Direct | ||
| Heat, North Phoenix/Glendale | 2021-06-29 | Unknown | Indirect | ||
| Heat, North Phoenix/Glendale | 2021-06-29 | Unknown | Indirect | ||
| Heat, North Phoenix/Glendale | 2021-06-29 | Unknown | Indirect | ||
| Heat, Buckeye/Avondale | 2021-06-29 | Unknown | Indirect | ||
| Heat, Central Phoenix | 2021-06-30 | Unknown | Indirect | ||
| Heat, Central Phoenix | 2021-06-30 | Unknown | Indirect | ||
| Heat, Buckeye/Avondale | 2021-06-30 | Unknown | Indirect | ||
| Heat, Buckeye/Avondale | 2021-06-30 | Unknown | Indirect | ||
| Heat, Buckeye/Avondale | 2021-06-30 | Unknown | Indirect | ||
| Heat, Buckeye/Avondale | 2021-06-30 | Unknown | Indirect |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2021Every state in 2021This day in weather historyWarnings in Arizona, June 2021
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: 1061109, 1061110, 1061112, 1061113, 1061121, 1061122, 1061115, 1061116, 1061117, 1061118, 1061119, 1061120.