Alert archive / Arizona / Special Weather Statements in 2021

Special Weather Statement, NWS Phoenix, AZ

August 31, 2021Maricopa County, Arizona

NWS Phoenix, AZ issued this special weather statement at Aug 31, 2021, 12:06 AM MST for Maricopa County, Arizona. It was in force for 39 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: Aug 31, 2021, 12:06 AM MST (07:06 UTC)
Expired: Aug 31, 2021, 12:45 AM MST
In force: 39 min
Issued by: NWS Phoenix, AZ
Hail: 0.00 in
Wind: 40

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 93 km from the middle of the area, began a volume at 07:08 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

Yuma Prvg Ground, AZ (K1Y7), launched 00:00Z, 7.1 hours before the alert went out and 177 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 761 J/kg
Mixed-layer CIN: -65 J/kg
Mixed-layer LCL: 2897 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 34 m²/s²
0-3 km storm-relative helicity: 51 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, 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 this special weather statement went out at Aug 30, 10:20 PM MST, 1 hour 46 minutes earlier.

Area forecast discussion, Aug 30, 10:20 PM MST, 1 hour 46 minutes before

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In the hours before

Local storm report, Aug 30, 6:10 PM MST, 5 hours 56 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
610 PM MST MON AUG 30 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0400 PM     TSTM WND GST     14 NNE MIDLAND          34.06N 114.73W
08/30/2021  M57 MPH          RIVERSIDE          CA   OFFICIAL NWS OBS

            RICE VALLEY RAWS WIND GUST TO 57 MPH. TIME
            ESTIMATE BASED ON RADAR.

&&

MP

Special weather statement, Aug 30, 7:37 PM MST, 4 hours 29 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
737 PM PDT Mon Aug 30 2021

CAZ563-564-568-310300-
Chuckwalla Mountains CA-Salton Sea CA-Chiriaco Summit CA-
737 PM PDT Mon Aug 30 2021

...A strong thunderstorm will impact portions of northern Imperial
and Riverside Counties through 800 PM PDT...

At 736 PM PDT, Doppler radar was tracking a strong thunderstorm over
North Shore, or 16 miles southwest of Chiriaco Summit. This storm was
nearly stationary.

HAZARD...Wind gusts of 50 to 55 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...
North Shore.

This includes CA Route 111 between mile markers 60 and 65.

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 3352 11604 3352 11595 3364 11595 3352 11575
      3336 11576 3338 11591 3348 11607 3350 11608
TIME...MOT...LOC 0236Z 144DEG 2KT 3351 11593

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...55 MPH

INS

Special weather statement, Aug 30, 8:18 PM MST, 3 hours 48 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
818 PM PDT Mon Aug 30 2021

CAZ569-570-310345-
Palo Verde Valley CA-Chuckwalla Valley CA-
818 PM PDT Mon Aug 30 2021

...A strong thunderstorm will impact portions of northwestern La Paz
and Riverside Counties through 845 PM PDT...

At 818 PM PDT, Doppler radar was tracking a strong thunderstorm 11
miles east of Midland, or 26 miles southwest of Parker. This storm
was nearly stationary.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Midland.

This includes CA Route 95 between mile markers 18 and 21.

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 3402 11464 3387 11451 3377 11457 3379 11472
      3387 11481
TIME...MOT...LOC 0318Z 115DEG 3KT 3386 11460

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

INS

Special weather statement, Aug 31, 12:06 AM MST, 0 minutes before

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The office that day

Everything else NWS Phoenix, AZ issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 30, 8:18 PM MST	Special Weather Statement	PSR		27 min
Aug 30, 9:06 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz	5 hr
Aug 30, 10:59 PM MST	Areal Flood Advisory	PSR	Maricopa, Pinal	4 hr
Aug 30, 11:17 PM MST	Areal Flood Advisory	PSR	La Paz	3 hr
Aug 31, 12:24 AM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Aug 31, 12:50 AM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Aug 31, 2:55 AM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Aug 31, 5:52 AM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Aug 31, 12:39 PM MST	Special Weather Statement	PSR		66 min
Aug 31, 1:13 PM MST	Areal Flood Advisory	PSR	La Paz	6 hr
Aug 31, 1:24 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz	13 hr
Aug 31, 1:35 PM MST	Special Weather Statement	PSR		70 min
Aug 31, 4:55 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila, Maricopa	3 hr
Aug 30, 5:14 PM MST	Flash Flood Warning Considerable damage threat	PSR	Imperial, Riverside	4 hr
Aug 30, 6:49 PM MST	Areal Flood Advisory	PSR	Imperial	3 hr
Aug 30, 7:37 PM MST	Special Weather Statement	PSR	Riverside	23 min
Aug 30, 7:52 PM MST	Areal Flood Advisory	PSR	Riverside	23 min
Aug 30, 8:13 PM MST	Flash Flood Warning Considerable damage threat	PSR	Riverside	50 min
Aug 31, 5:46 AM MST	Areal Flood Advisory	PSR	Imperial	3 hr
Aug 31, 3:48 PM MST	Special Weather Statement	PSR	Imperial	87 min
Aug 31, 4:15 PM MST	Special Weather Statement	PSR	Imperial	90 min
Aug 31, 4:30 PM MST	Severe Thunderstorm Warning	PSR	Imperial	75 min

Nearby

Special Weather Statements in Arizona, 2021 Every special weather statement 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.