An upper level ridge over the western CONUS led to temperatures near to slightly above normal across Phoenix. According to the Maricopa County Department of Public Health, 8 heat-associated fatalities occurred during this time.
Every event with a place to put it; 7 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 upper level ridge over the western CONUS led to temperatures near to slightly above normal across Phoenix. According to the Maricopa County Department of Public Health, 8 heat-associated fatalities occurred during this time.
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 16, 4:45 PM MST, 15 minutes earlier.
Area Forecast Discussion National Weather Service Phoenix AZ 445 PM MST Tue Aug 16 2022 .UPDATE...Updated 00Z Aviation Discussion. && .SYNOPSIS... Temperatures will climb to near to slightly above normal through Wednesday, with daily isolated showers and thunderstorms. Beginning late Wednesday, deep monsoonal moisture will return to southern Arizona leading to much better chances for showers and thunderstorms. Heavy rainfall and localized flooding are likely to impact portions of south-central and eastern Arizona later this week, with chances peaking on Friday through Sunday. Temperatures are also forecast to cool to well below normal with highs across a good portion of the lower deserts falling into the nineties or even upper eighties by Friday. && .DISCUSSION... A broad area of ridging remains in place across the northern portions of the United States and Canada with near or below normal heights across the Desert Southwest. There are several mesolows in the area, including one southeast of Phoenix that will drift up towards our forecast area this afternoon. Further east near the Big Bend area of Texas, a much stronger upper level low is slowly drifting west, but for now is not impacting the forecast area. Visible satellite shows partly sunny skies, with a few thunderstorms popping up over the higher terrain. ACARS soundings show a cap at the top of the boundary layer, which should keep storms from proliferating in the valleys too much for now, especially near Phoenix. For this afternoon we are looking at scattered storms developing over the higher terrain, especially southeast California where moisture and instability profiles are a bit better. HREF guidance shows high confidence (50-70%) chance of gusty outflow winds of at least 35 kts over southeast California today with a lower (20-40%) chance of such winds for the rest of the forecast area. Because PWAT remains elevated at 1.7-2.1", locally heavy rain will also be a threat. Further, with weak winds aloft, storms will not move very quickly. For the Phoenix area, sufficient destabilization for storms is in question, but it does appear that a few storms will pop up this afternoon or evening with a 10-20% chance of rain in any given location. As for temperatures, warm to hot conditions will continue through Wednesday with highs in the 103-107 range for the lower deserts, but with elevated moisture levels it will not feel like our more typical dry heat. For the Wednesday through early Friday period we will see an increasing storm threat in response to the previously mentioned upper level low centered near the Texas/Mexico border. Several factors will work together to enhance the storm threat as it approaches. First, mid level winds in the 600-400 mb layer will shift to northeast and strengthen. This will act to strengthen wind shear and the steering flow from off the higher terrain. Second, an influx of deep moisture on Wednesday will send PWAT values close to 2" for much of the area. Third, there will be some forced ascent as the storm system approaches. These factors should allow for numerous high terrain storms to develop along the Rim with a decent (30-50%) chance of these storms moving into the valleys of Arizona from the northeast during the afternoon hours. Should this scenario unfold all of our typical monsoon hazards would be possible, but wind and dust typically dominate in northeast flow events. Heading into Thursday and especially Friday it may be that excessive cloudiness limits storm chances somewhat, but this outcome will depend on what happens in the previous days in large measure. There is also still some uncertainty with respect to the track of the low pressure area, and if it tracks further south than modeled our risk of storms would diminish. Friday will be a transitional day for what looks to be the main event and potentially a significant precipitation event for south-central Arizona. Setting the stage will be a strengthening trough to the northwest of the forecast area, which will put southern Arizona under excellent diffluent flow aloft with strongly forced ascent, especially on Saturday. Low level moisture transport will strengthen, with PWAT climbing above 2", which is near the max NAEFS climatology for this time of year and above the 99% percentile. Further, due to the proximity of the trough and the other upper level low (which will still be south of the area), wind shear will increase. Taken together, these factors strongly support widespread and potentially heavy precipitation. ECMWF EFI precipitation depicts values of 0.7-0.9 across the area on Saturday. The shift of tails is relatively minimal, and a perusal of the ensemble reveals good consistency in precipitation totals compared to usual. What this likely means is higher confidence in most locations getting a good soaking, rather than a few locations getting a lot of rain while most others get little to none. Accordingly, WPC QPF continues to show potentially large storm totals of 1-3" between Friday and Sunday evening for south-central Arizona. Lower totals of less than 1" are forecast for SE California during this period. It is anticipated that a flood watch will eventually be needed for south-central Arizona if the forecast remains consistent. Temperatures will also cool off considerably by Friday with highs falling well into the 90s over a good portion of the lower deserts. If models end up being correct with the amount of clouds and rainfall over the area later this week, some lower desert areas likely won't get out of the 80s on Saturday. The NBM even has a 20% chance that the Phoenix area fails to reach 85F for the high on Saturday. Widespread rain chances may also linger into Sunday, but models mostly show waining upper level support by early Sunday while the disturbance to our south weakens considerably. By early next week, there is fairly good ensemble agreement our region will see a gradual drying trend with northerly upper level flow becoming more dominant. && .AVIATION...Updated 2345Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Current light westerly winds are expected to continue thru shortly after midnight, then becoming typical easterly drainage winds thereafter. Thunderstorm chances to remain low thru tonight as most activity will remain focused across the high terrain. It's not out of the question to see a few isolated vicinity showers pop up across the metro this evening, but confidence (10-20%) chance remains too low to include anything more then VCSH in the TAFs at this point. Chances are a little more likely (20-30% chance) that current westerly winds could be enhanced a bit from outflows from t-storms over SW Maricopa County, but confidence remains low on if/when any outflows impact the terminals, Expect SCT-BKN clouds to remain mostly aoa 8 kft through this evening. After winds shift to easterly late tonight, expecting these easterly winds to continue thru early afternoon Wednesday, then switch to typical westerly winds during the mid-afternoon hours. A better chance (40-60%) exists for t-storms impacting the terminals Wednesday afternoon/evening as moisture/instability increases across the region. Have added VCTS in the TAFs at this point (given uncertainties in timing), with winds likely shifting to a northeasterly direction. There are also indications that lighter SHRA/isolated T-storm activity could persist well into Wednesday night as well. Southeast California/Southwest Arizona including KIPL and KBLH: Winds through the period will mostly favor a southerly to southeasterly component outside of any potential thunderstorm outflows. It appears that the t-storm activity that developed across the region is diminishing at this hour, thus have only included VCSH in the 00Z TAF suite for the next few hours, with only a remote (10- 20%) chance that t-storms will directly impact either SE CA terminal. Chances for SHRA/t-storm activity increase again Wednesday afternoon/evening, but remain too low (10-20%) to include anything more than VCSH in the TAFs at this point. && .FIRE WEATHER... Daily chances for mostly isolated thunderstorms are expected through Wednesday afternoon areawide with chances increasing across southeast and south-central Arizona by Wednesday evening. A weather disturbance along with deep tropical moisture are then expected to impact much of Arizona as early as Thursday, likely peaking at some point Friday into Saturday. This will provide widespread wetting rains and cooler temperatures across the area, especially across southeast and south-central Arizona. Humidities will remain fairly elevated through mid week with afternoon minimum RH values into a 25-30% range, before climbing back upward later this week as even higher moisture levels return and temperatures cool off. Impacts from thunderstorm activity will increase starting Thursday with strong winds, heavy rainfall, and flooding all possible through the upcoming weekend. Winds through the majority of the period will remain light, with the exception of nearby thunderstorms or thunderstorm outflow generating stronger gusts. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && DISCUSSION...Hodges/Kuhlman AVIATION...Percha FIRE WEATHER...Kuhlman
Special Weather Statement
National Weather Service Phoenix AZ
230 PM PDT Tue Aug 16 2022
CAZ560-561-568-162215-
Chiriaco Summit CA-Joshua Tree NP East CA-Joshua Tree NP West CA-
230 PM PDT Tue Aug 16 2022
...A strong thunderstorm will impact portions of Riverside County
through 315 PM PDT...
At 230 PM PDT, Doppler radar was tracking a strong thunderstorm over
Chiriaco Summit. This storm was nearly stationary.
HAZARD...Wind gusts of 50 to 55 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Chiriaco Summit and Cottonwood Visitor.
This includes CA Interstate 10 between mile markers 78 and 94.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.
&&
LAT...LON 3365 11558 3358 11579 3373 11594 3386 11564
TIME...MOT...LOC 2130Z 142DEG 3KT 3369 11574
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...55 MPH
INSSpecial Weather Statement
National Weather Service Phoenix AZ
258 PM PDT Tue Aug 16 2022
CAZ563-564-568-162245-
Chuckwalla Mountains CA-Salton Sea CA-Chiriaco Summit CA-
258 PM PDT Tue Aug 16 2022
...A strong thunderstorm will impact portions of north central
Imperial and Riverside Counties through 345 PM PDT...
At 257 PM PDT, Doppler radar was tracking a strong thunderstorm 10
miles northeast of Bombay Beach, or 13 miles south of Chiriaco
Summit. This storm was nearly stationary.
HAZARD...Wind gusts up to 50 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Bombay Beach and Imperial Hot Mineral Springs.
This includes CA Route 111 between mile markers 52 and 57.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 3351 11576 3359 11555 3344 11541 3332 11573
TIME...MOT...LOC 2157Z 337DEG 1KT 3348 11563
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH
SDBPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
306 PM MST TUE AUG 16 2022
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0227 PM TSTM WND DMG 1 WSW CHIRIACO SUMMIT 33.66N 115.73W
08/16/2022 RIVERSIDE CA DEPT OF HIGHWAYS
THUNDERSTORM WINDS FLIPPED 4 SEMIS ON I-10.
&&
JMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
328 PM MST TUE AUG 16 2022
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0320 PM FLASH FLOOD 4 N COTTONWOOD VISITOR 33.81N 115.78W
08/16/2022 RIVERSIDE CA PARK/FOREST SRVC
SOUTH END OF JOSHUA TREE NP CLOSED DUE TO
FLOODING BETWEEN OCOTILLO PATCH AND
COTTONWOOD VISITOR CENTER.
&&
JMSpecial Weather Statement
National Weather Service Phoenix AZ
339 PM PDT Tue Aug 16 2022
CAZ560-162315-
Joshua Tree NP West CA-
339 PM PDT Tue Aug 16 2022
...A strong thunderstorm will impact portions of San Bernardino and
Riverside Counties through 415 PM PDT...
At 339 PM PDT, Doppler radar was tracking a strong thunderstorm 13
miles south of Twentynine Palms. This storm was nearly stationary.
HAZARD...Winds in excess of 40 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Lost Horse-Keys Village.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 3412 11614 3412 11612 3395 11595 3392 11595
3382 11611 3392 11620 3392 11629 3394 11635
TIME...MOT...LOC 2239Z 130DEG 3KT 3396 11613
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH
SDBSpecial Weather Statement
National Weather Service Phoenix AZ
432 PM MST Tue Aug 16 2022
AZZ532-535-536-170015-
Gila River Valley AZ-Southeast Yuma County AZ-Yuma AZ-
432 PM MST Tue Aug 16 2022
...Strong thunderstorms will impact portions of south central Yuma
County through 515 PM MST...
At 432 PM MST, Doppler radar was tracking strong thunderstorms along
a line extending from 9 miles south of Ligurta to 23 miles southeast
of Wellton. These storms were nearly stationary.
HAZARD...Winds in excess of 40 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
These storms will remain over mainly rural areas of south central
Yuma County.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 3230 11417 3239 11428 3254 11439 3265 11433
3264 11412 3230 11371 3224 11399
TIME...MOT...LOC 2332Z 239DEG 1KT 3254 11425 3236 11398
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH
SDBThe national radar mosaic for the moment the first event began.
7 heat. Local standard time, as filed.
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 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 fatalities (1 direct and 1 indirect) 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 indirect fatality was 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, East Valley | 2022-08-16 | Unknown | Direct | ||
| Heat, Buckeye/Avondale | 2022-08-16 | Unknown | Direct | ||
| Heat, Buckeye/Avondale | 2022-08-17 | Unknown | Direct | ||
| Heat, Scottsdale/Paradise Valley | 2022-08-17 | Unknown | Indirect | ||
| Heat, Central Phoenix | 2022-08-17 | Unknown | Direct | ||
| Heat, Central Phoenix | 2022-08-17 | Unknown | Indirect | ||
| Heat, Central Phoenix | 2022-08-18 | Unknown | Indirect | ||
| Heat, Scottsdale/Paradise Valley | 2022-08-18 | Unknown | Indirect |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2022Every state in 2022This day in weather historyWarnings in Arizona, August 2022
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: 1148951, 1148952, 1148953, 1148954, 1148955, 1148956, 1148957.