Alert archive / Arizona / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 108, NWS Phoenix, AZ
NWS Phoenix, AZ issued this severe thunderstorm warning at Sep 18, 2021, 3:00 PM MST for Maricopa County, Pinal County, Arizona. It was in force for 45 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Sep 18, 2021, 3:00 PM MST (22:00 UTC)
- Expired
- Sep 18, 2021, 3:45 PM MST
- In force
- 45 min
- Issued by
- NWS Phoenix, AZ
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Maricopa County, AZ, Pinal County, AZ
The radar
The Phoenix radar (KIWA), 30 km from the middle of the area, began a volume at 22:01 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Phoenix, AZ (KPSR), launched 12:00Z, 10.0 hours before the alert went out and 36 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 240 J/kg
- Mixed-layer CIN
- -237 J/kg
- Mixed-layer LCL
- 2129 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 7 m²/s²
- 0-3 km storm-relative helicity
- 94 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.5
The text
As transmitted.
036 WUUS55 KPSR 182200 SVRPSR AZC013-021-182245- /O.NEW.KPSR.SV.W.0108.210918T2200Z-210918T2245Z/ BULLETIN - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Warning National Weather Service Phoenix AZ 300 PM MST Sat Sep 18 2021 The National Weather Service in Phoenix has issued a * Severe Thunderstorm Warning for... Maricopa County in south central Arizona... Pinal County in southeastern Arizona... * Until 345 PM MST. * At 300 PM MST, a severe thunderstorm was located near Maricopa, or 11 miles southwest of Sun Lakes, moving northeast at 40 mph. HAZARD...60 mph wind gusts. SOURCE...Radar indicated. IMPACT...Expect damage to roofs, siding, and trees. * Locations impacted include... Chandler, Gilbert, Sun Lakes, Maricopa, Queen Creek, Chandler Heights, Gilbert City Hall, Tumbleweed Park, Chandler City Hall, San Tan Village Mall, Seville, Bapchule, Estrella Sailport, Olberg and Phoenix Mesa Gateway Airport. This includes the following highways... AZ Interstate 10 between mile markers 164 and 181. AZ Route 87 between mile markers 149 and 166. AZ Route 202 between mile markers 39 and 50. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. Large hail and damaging winds and continuous cloud to ground lightning is occurring with this storm. Move indoors immediately. Lightning is one of nature's leading killers. Remember, if you can hear thunder, you are close enough to be struck by lightning. Torrential rainfall is occurring with this storm, and may lead to flash flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 3291 11202 3317 11224 3335 11175 3322 11151 TIME...MOT...LOC 2200Z 238DEG 35KT 3311 11203 HAIL THREAT...RADAR INDICATED MAX HAIL SIZE...<.75 IN WIND THREAT...RADAR INDICATED MAX WIND GUST...60 MPH $$ INS
2 follow-up statements
348 WWUS55 KPSR 182220 SVSPSR Severe Weather Statement National Weather Service Phoenix AZ 320 PM MST Sat Sep 18 2021 AZC013-021-182245- /O.CON.KPSR.SV.W.0108.000000T0000Z-210918T2245Z/ Maricopa AZ-Pinal AZ- 320 PM MST Sat Sep 18 2021 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM MST FOR MARICOPA AND PINAL COUNTIES... At 320 PM MST, a severe thunderstorm was located over Sun Lakes, moving northeast at 40 mph. HAZARD...60 mph wind gusts. SOURCE...Radar indicated. IMPACT...Expect damage to roofs, siding, and trees. Locations impacted include... Chandler, Gilbert, Sun Lakes, Maricopa, Queen Creek, Chandler Heights, Gilbert City Hall, Tumbleweed Park, Chandler City Hall, San Tan Village Mall, Seville, Bapchule, Olberg, Phoenix Mesa Gateway Airport and San Tan Mountain Park. This includes the following highways... AZ Interstate 10 between mile markers 164 and 181. AZ Route 87 between mile markers 149 and 166. AZ Route 202 between mile markers 39 and 50. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. Continuous cloud to ground lightning is occurring with this storm. Move indoors immediately. Lightning is one of nature's leading killers. Remember, if you can hear thunder, you are close enough to be struck by lightning. Torrential rainfall is occurring with this storm, and may lead to flash flooding. Do not drive your vehicle through flooded roadways. && LAT...LON 3294 11197 3320 11215 3335 11175 3322 11151 TIME...MOT...LOC 2220Z 238DEG 35KT 3322 11183 HAIL THREAT...RADAR INDICATED MAX HAIL SIZE...<.75 IN WIND THREAT...RADAR INDICATED MAX WIND GUST...60 MPH $$ INS
426
WWUS55 KPSR 182243
SVSPSR
Severe Weather Statement
National Weather Service Phoenix AZ
343 PM MST Sat Sep 18 2021
AZC013-021-182253-
/O.EXP.KPSR.SV.W.0108.000000T0000Z-210918T2245Z/
Maricopa AZ-Pinal AZ-
343 PM MST Sat Sep 18 2021
...THE SEVERE THUNDERSTORM WARNING FOR MARICOPA AND PINAL COUNTIES
WILL EXPIRE AT 345 PM MST...
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire. However gusty winds and heavy rain are still
possible with this thunderstorm.
LAT...LON 3294 11197 3320 11215 3335 11175 3322 11151
TIME...MOT...LOC 2243Z 238DEG 35KT 3333 11162
$$
INSThe office that day
Everything else NWS Phoenix, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 17, 5:43 PM MST | Special Weather Statement | PSR | Yuma | 32 min |
| Sep 18, 11:51 AM MST | Special Weather Statement | PSR | Maricopa | 24 min |
| Sep 18, 12:13 PM MST | Areal Flood Advisory | PSR | Maricopa | 22 min |
| Sep 18, 12:22 PM MST | Special Weather Statement | PSR | Maricopa | 38 min |
| Sep 18, 12:35 PM MST | Flash Flood Warning | PSR | Maricopa, Pinal | 4 hr |
| Sep 18, 12:48 PM MST | Special Weather Statement | PSR | Maricopa | 27 min |
| Sep 18, 1:11 PM MST | Areal Flood Advisory | PSR | Maricopa | 2 hr |
| Sep 18, 1:30 PM MST | Special Weather Statement | PSR | Maricopa | 30 min |
| Sep 18, 1:39 PM MST | Special Weather Statement | PSR | Maricopa | 66 min |
| Sep 18, 1:46 PM MST | Areal Flood Advisory | PSR | Maricopa | 119 min |
| Sep 18, 2:05 PM MST | Special Weather Statement | PSR | 25 min | |
| Sep 18, 2:15 PM MST | Dust Storm Advisory | PSR | Maricopa, Pinal | 45 min |
| Sep 18, 2:46 PM MST | Special Weather Statement | PSR | 44 min | |
| Sep 18, 2:54 PM MST | Dust Storm Advisory | PSR | Maricopa, Pinal | 66 min |
| Sep 18, 3:08 PM MST | Areal Flood Advisory | PSR | Maricopa, Pinal | 3 hr |
| Sep 18, 3:17 PM MST | Dust Storm Warning | PSR | Maricopa, Pinal | 43 min |
| Sep 18, 3:23 PM MST | Severe Thunderstorm Warning | PSR | Maricopa, Pinal | 35 min |
| Sep 18, 4:34 PM MST | Special Weather Statement | PSR | Pinal | 41 min |
Nearby
Severe Thunderstorm Warnings in Arizona, 2021Every severe thunderstorm warning in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.