Strong high pressure centered over the Desert Southwest brought record breaking temperatures and excessive heat warning conditions to the region. The deadly heat resulted in 21 fatalities (17 direct and 4 indirect) according to the Maricopa County Department of Public Health.
Every event with a place to put it; 20 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.
Strong high pressure centered over the Desert Southwest brought record breaking temperatures and excessive heat warning conditions to the region. The deadly heat resulted in 21 fatalities (17 direct and 4 indirect) according to 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 Aug 1, 10:54 PM MST, 1 hour 6 minutes earlier.
Area Forecast Discussion National Weather Service Phoenix AZ 1054 PM MST Thu Aug 1 2019 .UPDATE... Updated 06Z aviation discussion. && .SYNOPSIS... A warming and drying trend will begin today, resulting in rather low grade monsoon conditions across the area. Thunderstorms will generally be confined to high terrain areas in Arizona each day, with little chances across the lower deserts. High temperatures will be a few degrees below normal today but will rise well above normal by the weekend. Hotter deserts this weekend into early next week will exceed 110 degrees. && .DISCUSSION... High pressure remains centered east of the area, continuing to place our region under light south to southwesterly flow aloft. This has caused drier air, primarily in the mid-levels to filter into the region. The majority of the moisture remains near the 700 mb level, especially across Arizona where the flow at that level is more southerly. This, combined with daytime heating has resulted in scattered cumulus clouds across the region, especially over the high terrain. The SPC mesoscale analysis is showing MLCAPE values between 500 J/kg in eastern Gila county rising to around 1500-2000 J/kg in central and southwestern Arizona. Despite this, drier and warmer air aloft is prohibiting deeper and stronger convection to develop, even over the high terrain. A very weak steering flow in place will limit any organization and storms that do develop will quickly pulse up and down. Thus, outside of isolated activity popping up over the high terrain, the lower deserts will remain pretty quiet today with mostly sunny skies. Any storm that does develop over the high terrain will be capable of producing frequent lightning, gusty winds, and brief heavy rain. With light storm motion in place, isolated flooding could occur with any storm as well. Tomorrow's forecast looks very similar, the only difference is that aforementioned high starts to nudge a little further west, causing heights over the region to increase closer to 594 dm. This will cause a decent warm up with high temperatures rising about 4-5 degrees tomorrow. Precipitation chances also look a little lower since the high will be closer, 500 mb heights will be warmer, and more subsidence a loft will help in limiting thunderstorm development. Over the weekend and into the early part of next week, we are expecting the monsoon to remain in a rather low grade mode, with most of the convection confined to the high terrain areas of northern and eastern Arizona. POPs over lower deserts west of Phoenix will typically remain in the single digits and storms over high terrain east of Phoenix will be isolated to scattered in nature. The upper high is forecast to strengthen a bit with heights climbing above 594dm over the deserts by Sunday. As such highs will climb a few degrees above seasonal normals with hotter deserts west of Phoenix reaching or exceeding 110. Phoenix will see highs near 109 each day. At this time there is very little agreement between the models such as operational GFS and ECMWF in the details such as nature and timing of any vort maxes or inverted trofs. As such the forecast will be rather broad brushed in nature, typical for this time of year. && .AVIATION...Updated at 0554 UTC. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Minimal aviation concerns are expected through the TAF period as light and variable winds become easterly overnight before veering to westerly around 19-20Z. Winds will generally remain below 10 knots aside from any weak thunderstorm outflows that attempt to move in from the south-southeast where 00Z HREF depict the most robust convection. However, convection is not expected to affect the Phoenix sites as the lower deserts continue to dry out. Cloud bases should remain above 8-10 kft with perhaps SCT-BKN 25 kft cloud decks associated with convective anvils from the southeast. Southeast California/Southwest Arizona including KIPL and KBLH: No aviation concerns are expected through the TAF period as winds generally remain below 10 knots under clear skies. Winds will generally favor downsloping southwesterlies tonight and tomorrow night with S-SE winds otherwise at KIPL. KBLH will generally favor southwesterly headings tonight with a long period of light and variable winds in the morning before become southerly after 20Z. Aviation Discussion not updated for amended TAFs. && .FIRE WEATHER... Sunday through Thursday: Isolated to scattered showers and thunderstorms will continue over the higher terrain of south- central AZ each day. There is still a little bit of uncertainty on exactly which day will be more active and allow thunderstorms to make it into the lower deserts. As of now, it's looking like Tuesday and Wednesday could potentially be more favorable for that. High temperatures will climb at least several degrees above seasonal normal this weekend especially over hotter western deserts into far southeast California - with the hotter readings in excess of 110 degrees. A cooling trend back toward normal temperatures will commence on Tuesday, with temperatures forecast to fall near or below normal on Wednesday and Thursday. Minimum humidities will dip below 20% Sunday through Tuesday. Look for humidity to rise further next Wednesday into Thursday with minimum RH values between 15 and 25 percent over much of the lower elevations. Overnight recovery will remain fair to good (excellent for higher terrain of south-central AZ). Winds overall will follow familiar diurnal patterns favoring southwest and west in the afternoons and evenings. && .SPOTTER INFORMATION STATEMENT... Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && DISCUSSION...Hernandez/CB AVIATION...Hopper FIRE WEATHER...Hernandez/CB
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
657 PM MST THU AUG 1 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0510 PM TSTM WND DMG 2 N MESA 33.44N 111.83W
07/30/2019 MARICOPA AZ BROADCAST MEDIA
DELAYED REPORT. SOCIAL MEDIA AND BROADCAST
MEDIA REPORTS OF 25 MATURE CYPRESS AND OLIVE
TREES KNOCKED DOWN IN CITY OF MESA CEMETERY.
TIME ESTIMATED FROM RADAR.
&&
SDBThe national radar mosaic for the moment the first event began.
17 excessive heat, 3 heat. Local standard time, as filed.
Three fatalities (two direct and one indirect) were reported by the Maricopa County Department of Public Health, with their details, such as age, gender and circumstances unavailable.
Two fatalities (one direct and one indirect) were reported by the Maricopa County Department of Public Health, with their details, such as age, gender and circumstances unavailable.
Six direct fatalities were reported by the Maricopa County Department of Public Health, with their details, such as age, gender and circumstances unavailable.
Four direct fatalities were reported by the Maricopa County Department of Public Health, with their details, such as age, gender and circumstances unavailable.
Two direct fatalities were reported by the Maricopa County Department of Public Health, with their details, such as age, gender and circumstances unavailable.
Two direct fatalities were reported by the Maricopa County Department of Public Health, with their details, such as age, gender and circumstances unavailable.
Two indirect fatalities were 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.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2019Every state in 2019This day in weather historyWarnings in Arizona, August 2019
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: 930994, 930995, 930996, 930997, 930998, 930999, 931000, 931001, 931002, 931003, 931004, 931005, 931006, 931007, 931008, 931009, 931010, 931011, 931012, 931013.