Hot temperatures resulted in several heat-associated fatalities during the first part of the month. Eight heat-associated fatalities (3 direct and 5 indirect) were reported by the Maricopa County Department of Public Health.
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 PSR wrote it up.
Hot temperatures resulted in several heat-associated fatalities during the first part of the month. Eight heat-associated fatalities (3 direct and 5 indirect) were reported by the Maricopa County Department of Public Health.
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 Sep 1, 1:51 PM MST, 3 hours 9 minutes earlier.
Area Forecast Discussion National Weather Service Phoenix AZ 151 PM MST Sat Sep 1 2018 .SYNOPSIS... Storm chances this weekend will be limited to areas well east of the Lower Colorado River Valley and will favor the higher terrain. Showers and thunderstorms will be more likely in the overnight and morning hours instead of afternoon and evening. After Monday, storm chances will only be slight and will be confined to the higher terrain east of Phoenix. Anticipate high temperatures slightly below normal into early next week before warming a few degrees during the latter half of next week. && .DISCUSSION... The trough will continue to dig further south into southern Arizona today. In addition, moisture continues to move into southeast Arizona and current SPC mesoanalysis shows 1 to 1.3 inches of PWAT in southeast AZ. In our forecast area, drier air exists, with PWATS ranging from .5 inches in southeast California to close to an inch in south-central AZ. Thus, the greatest instability for us will primarily be over the higher terrain east of Phoenix where about 500 to 1500 J/kg of CAPE is forecast. As the day progresses and the afomentioned trough continues to move south, a pretty decent area of divergence will develop in southern Arizona/ northern Mexico between the mid-level trough and the subtropical ridge to our southwest. In addition, cooler temperatures aloft will also spread into southern Arizona as that trough moves south. It seems like the most favorable areas for thunderstorms will be in Gila county as well as far eastern Maricopa and Pinal counties. Hi res models show activity mostly over southeast Arizona but there continues to be some indication that weaker showers and thunderstorms could make it into the lower deserts of south-central Arizona. The stronger storms that do develop today will have the potential to produce frequent lightning, gusty winds, and small hail. With a drier airmass in place don't expect flooding to be that big of a concern. && .PREVIOUS DISCUSSION... Sunday and Monday... An upper trough is moving through the Great Basin and into the Desert Southwest early this morning. The main batch of PVA is tracking north of our forecast area, but the left exit region of a jet streak is nosing into the forecast area. 03Z PSR sounding showed good boundary layer moisture and 1000+ J/kg of CAPE with not much CIN. Latest SPC mesoanalysis shows 1000-2000 J/kg of MUCAPE over south-central AZ with 500-1500 J/kg of MLCAPE but with considerable CIN over the lower elevations. Meanwhile, bulk shear is 25-30kts. Some vigorous, but isolated, storms have already occurred early this morning over southern Gila County. For the second night in a row, the 00Z and 06Z NAMNest has been showing atypical nocturnal convection over south-central Arizona (including metro Phoenix) for late Friday night/Saturday morning (now) with the stronger storms over the higher terrain east of Phoenix. Latest runs of the HRRR support this as well - but with even less activity over metro Phoenix. The NCEP WRF-ARW and NMM have been underdone. HREF hinted at it but was underdone. One limiting factor for the lower elevations - especially southwest of metro Phoenix - is that temperatures aloft are still warm due to the influence of the anticyclone centered west of Baja. Plus the air is drier. For the daylight hours, anticipate isolated to scattered activity to continue this morning over south-central AZ (mainly higher terrain) before trending down in the afternoon as the short wave and associated jet streak weaken and track northeastward. High temperatures across the forecast area will be slightly cooler today - most noticeably over portions of south- central Arizona. The left exit region of another jet noses across Arizona this afternoon and overnight. But with a more southerly track - across southern Arizona. This is due the trough digging. Temperatures aloft will be even a bit cooler tonight and during the day Sunday than with the preceding wave. However, both the GFS and NAM indicate drier air advancing eastward tonight - at least across most of Maricopa and western Pinal Counties. This is supported by the SREF mean MUCAPE forecasts. However, there is a lot of spread amongst the members. There also appears to be less shear but a lot of spread in the solutions. CAMs depict best activity over southeast AZ but they also indicate the possibility of weaker showers over the lower elevations of south-central AZ (including metro Phoenix) for tonight into Sunday morning. NAM, GFS, and GEFS depict renewed moist for south-central Arizona (including the lower elevations) Sunday afternoon and overnight with more southerly flow in the lower levels. Thus another opportunity for mainly nocturnal precip. PoPs trend down for Monday afternoon as warmer air aloft starts moving in - at least Tuesday through Friday... GFS, GEFS, and ECMWF indicate only very limited storm potential the rest of the workweek due to drier air in place over our forecast area (though not far away). Kept lingering slight chance PoPs over the higher terrain of south-central AZ. && .AVIATION... South-Central Arizona including KPHX, KIWA, and KSDL: Afternoon and evening storm activity will be focused over higher terrain of northern and eastern Arizona this evening with storms remaining well east of the greater Phoenix area. Cloud cover will be kept into the SCT-BKN range, with bases aoa 10k feet. Winds to remain westerly into the wee hours of the morning on Sunday, then becoming/remaining easterly through Sunday afternoon. Shower/TS activity likely to return Sunday to the higher terrain east of Phoenix, but with only slight chances for storms to affect the terminals. Thus, will leave mention of TS out of the TAFS for now. Southeast California/Southwest Arizona including KIPL and KBLH: Expect little or no thunderstorm activity. If any storms form, anticipate they will be east of the Lower Colorado River Valley (LCRV). Winds to remain mainly southerly at KBLH and follow typical diurnal trends at KIPL. Aviation Discussion not updated for amended TAFs. && .FIRE WEATHER... Tuesday through Saturday: Southwesterly flow aloft will bring much drier air to the region for next week for a break in Monsoon activity over most of the forecast area, with the exception of a slight chance for thunderstorms over the higher terrain north and east of Phoenix each day. That will translate into minimum RH values of 10-15% on the lower deserts each day, with only fair to good overnight recoveries. Wind patterns will be different than recent weeks with southwest and west winds being prevalent across the region for a large portion of each day. && .SPOTTER INFORMATION STATEMENT... Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && DISCUSSION...Hernandez PREVIOUS DISCUSSION...AJ AVIATION...Percha FIRE WEATHER...Percha
The national radar mosaic for the moment the first event began.
8 heat. Local standard time, as filed.
One indirect fatality was reported by the Maricopa County Department of Public Health, with their details, such as age, gender and circumstances unavailable.
One direct fatality was reported by the Maricopa County Department of Public Health, with their details, such as age, gender and circumstances unavailable.
One indirect fatality was reported by the Maricopa County Department of Public Health, with their details, such as age, gender and circumstances unavailable.
One indirect fatality was reported by the Maricopa County Department of Public Health, with their details, such as age, gender and circumstances unavailable.
One direct fatality was reported by the Maricopa County Department of Public Health, with their details, such as age, gender and circumstances unavailable.
One indirect fatality was reported by the Maricopa County Department of Public Health, with their details, such as age, gender and circumstances unavailable.
One direct fatality was reported by the Maricopa County Department of Public Health, with their details, such as age, gender and circumstances unavailable.
One indirect fatality was reported by the Maricopa County Department of Public Health, with their details, such as age, gender and circumstances 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, East Valley | 2018-09-01 | Unknown | Indirect | ||
| Heat, Cave Creek/New River | 2018-09-01 | Unknown | Direct | ||
| Heat, Central Phoenix | 2018-09-02 | Unknown | Indirect | ||
| Heat, Buckeye/Avondale | 2018-09-02 | Unknown | Indirect | ||
| Heat, Scottsdale/Paradise Valley | 2018-09-02 | Unknown | Direct | ||
| Heat, Central Phoenix | 2018-09-05 | Unknown | Indirect | ||
| Heat, North Phoenix/Glendale | 2018-09-05 | Unknown | Direct | ||
| Heat, Central Phoenix | 2018-09-06 | Unknown | Indirect |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2018Every state in 2018This day in weather historyWarnings in Arizona, September 2018
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: 867361, 867362, 867363, 867364, 867365, 867366, 867367, 867368.