Alert archive / California / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 102, NWS Phoenix, AZ
NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 31, 2021, 4:30 PM PDT for Imperial County, California. It was in force for 75 min. 2 reports came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Aug 31, 2021, 4:30 PM PDT (23:30 UTC)
- Expired
- Aug 31, 2021, 5:45 PM PDT
- In force
- 75 min
- Issued by
- NWS Phoenix, AZ
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
County Imperial County, CA
The radar
The Yuma radar (KYUX), 117 km from the middle of the area, began a volume at 23:29 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 31, 4:53 PM PDT | TSTM WND DMG | 1 Ssw Wiest, CA | CORRECTS PREVIOUS TSTM WND DMG REPORT FROM 1 SSW WIEST. POWER POLE DOWN AND BLOCKING TRAFFIC. TIME ESTIMATED FROM RADAR. |
| Aug 31, 5:26 PM PDT | TSTM WND DMG | 6 Wnw Calipatria, CA | ***DELAYED REPORT*** PICTURE SHARED VIA SOCIAL MEDIA SHOWED MULTIPLE POWER POLES DOWN ALONG LINDSEY/GENTRY ROADS. TIME ESTIMATED FROM RADAR. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
San Diego, CA (KNKX), launched 12:00Z, 11.5 hours before the alert went out and 137 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 980 m above ground
- 0-6 km bulk shear
- 5 kt
- 0-1 km storm-relative helicity
- -12 m²/s²
- 0-3 km storm-relative helicity
- -16 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
771
WUUS55 KPSR 312330
SVRPSR
CAC025-010045-
/O.NEW.KPSR.SV.W.0102.210831T2330Z-210901T0045Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Phoenix AZ
430 PM PDT Tue Aug 31 2021
The National Weather Service in Phoenix has issued a
* Severe Thunderstorm Warning for...
Western Imperial County in southeastern California...
* Until 545 PM PDT.
* At 429 PM PDT, a severe thunderstorm was located near El Centro
Naval Airfield, or 7 miles northeast of Plaster City, moving north
at 25 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage
to roofs, siding, and trees.
* Locations impacted include...
El Centro, Calexico, Brawley, Imperial, Plaster City, Ocotillo,
Westmorland, Mt. Signal, El Centro Naval Airfield, Calipatria, Slab
City, Coyote Wells, Alamorio, Seeley and Wiest.
This includes the following highways...
CA Interstate 8 between mile markers 4 and 43.
CA Route 78 between mile markers 4 and 20.
CA Route 111 between mile markers 1 and 48.
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 3302 11604 3323 11599 3337 11551 3324 11541
3291 11541 3267 11550 3262 11610
TIME...MOT...LOC 2329Z 164DEG 23KT 3287 11576
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Hirsch1 follow-up statement
931
WWUS55 KPSR 010044
SVSPSR
Severe Weather Statement
National Weather Service Phoenix AZ
544 PM PDT Tue Aug 31 2021
CAC025-010054-
/O.EXP.KPSR.SV.W.0102.000000T0000Z-210901T0045Z/
Imperial CA-
544 PM PDT Tue Aug 31 2021
...THE SEVERE THUNDERSTORM WARNING FOR WESTERN IMPERIAL COUNTY WILL
EXPIRE AT 545 PM PDT...
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.
LAT...LON 3302 11604 3323 11599 3337 11551 3324 11541
3291 11541 3267 11550 3262 11610
TIME...MOT...LOC 0044Z 164DEG 23KT 3333 11592
$$
HirschThe office that day
Everything else NWS Phoenix, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 30, 5:14 PM PDT | Flash Flood Warning | PSR | Imperial, Riverside | 4 hr |
| Aug 30, 6:49 PM PDT | Areal Flood Advisory | PSR | Imperial | 3 hr |
| Aug 30, 7:37 PM PDT | Special Weather Statement | PSR | Riverside | 23 min |
| Aug 30, 7:52 PM PDT | Areal Flood Advisory | PSR | Riverside | 23 min |
| Aug 30, 8:13 PM PDT | Flash Flood Warning | PSR | Riverside | 50 min |
| Aug 30, 9:06 PM PDT | Flash Flood Warning | PSR | Riverside | 5 hr |
| Aug 31, 5:46 AM PDT | Areal Flood Advisory | PSR | Imperial | 3 hr |
| Aug 31, 1:13 PM PDT | Areal Flood Advisory | PSR | Imperial, Riverside | 6 hr |
| Aug 31, 1:24 PM PDT | Flash Flood Warning | PSR | Imperial, Riverside | 13 hr |
| Aug 31, 3:48 PM PDT | Special Weather Statement | PSR | Imperial | 87 min |
| Aug 31, 4:15 PM PDT | Special Weather Statement | PSR | Imperial | 90 min |
Nearby
Severe Thunderstorm Warnings in California, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.