Alert archive / Arizona / Special Weather Statements in 2021

Special Weather Statement, NWS Phoenix, AZ

July 20, 2021

NWS Phoenix, AZ issued this special weather statement at Jul 20, 2021, 11:51 PM MST. 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: Jul 20, 2021, 11:51 PM MST (06:51 UTC)
Expired: Jul 21, 2021, 12:30 AM MST
In force: 39 min
Issued by: NWS Phoenix, AZ

The radar

The Phoenix radar (KIWA), 74 km from the middle of the area, began a volume at 06:51 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 00:00Z, 6.9 hours before the alert went out and 74 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: 876 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 3033 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -3 m²/s²
0-3 km storm-relative helicity: 6 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 Jul 20, 10:12 PM MST, 1 hour 39 minutes earlier.

Area forecast discussion, Jul 20, 10:12 PM MST, 1 hour 39 minutes before

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In the hours before

Special weather statement, Jul 20, 6:22 PM MST, 5 hours 29 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
622 PM MST Tue Jul 20 2021

AZZ558-561-210200-
Dripping Springs AZ-Pinal/Superstition Mountains AZ-
622 PM MST Tue Jul 20 2021

...SIGNIFICANT WEATHER ADVISORY FOR GILA AND PINAL COUNTIES UNTIL 700
PM MST...

At 622 PM MST, Doppler radar was tracking a strong thunderstorm over
Christmas, moving west at 10 mph.

Pea size hail and wind gusts of 50 to 55 mph will be possible with
this storm.

Locations impacted include...
Hayden and Christmas.

This includes the following highways...
AZ Route 77 between mile markers 139 and 143, and between mile
markers 146 and 158.
AZ Route 177 near mile marker 138.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3311 11068 3308 11070 3308 11071 3307 11073
      3304 11072 3300 11075 3300 11080 3318 11091
      3324 11089 3315 11065 3313 11064
TIME...MOT...LOC 0122Z 105DEG 11KT 3310 11073

JS

Special weather statement, Jul 20, 7:22 PM MST, 4 hours 29 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
722 PM MST Tue Jul 20 2021

AZZ558-561-210315-
Dripping Springs AZ-Pinal/Superstition Mountains AZ-
722 PM MST Tue Jul 20 2021

...SIGNIFICANT WEATHER ADVISORY FOR GILA AND PINAL COUNTIES UNTIL 815
PM MST...

At 722 PM MST, Doppler radar was tracking a strong thunderstorm 10
miles north of Kearny, or 13 miles northwest of Christmas, moving
west at 10 mph.

Pea size hail and wind gusts of 50 to 55 mph will be possible with
this storm.

Locations impacted include...
Top-Of-The-World.

This includes US Highway 60 near mile marker 235.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3316 11085 3316 11089 3324 11094 3321 11101
      3322 11101 3336 11100 3326 11085
TIME...MOT...LOC 0222Z 104DEG 7KT 3321 11089

JS

Special weather statement, Jul 20, 8:19 PM MST, 3 hours 32 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
819 PM MST Tue Jul 20 2021

AZZ552-553-555-558-210400-
Northwest Pinal County AZ-Apache Junction/Gold Canyon AZ-Superior AZ-
Pinal/Superstition Mountains AZ-
819 PM MST Tue Jul 20 2021

...SIGNIFICANT WEATHER ADVISORY FOR MARICOPA AND PINAL COUNTIES UNTIL
900 PM MST...

At 819 PM MST, Doppler radar was tracking a strong thunderstorm over
Florence Junction, or 9 miles southeast of Gold Canyon, moving
northwest at 15 mph.

Winds in excess of 40 mph will be possible with this storm.

Locations impacted include...
Apache Junction, Gold Canyon, Florence Junction, Queen Valley,
Superstition Mountains, Gold Camp, Kings Ranch, Lost Dutchman State
Park and Goldfield.

This includes the following highways...
US Highway 60 between mile markers 195 and 219.
AZ Route 79 between mile markers 143 and 150.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3330 11120 3312 11129 3323 11158 3337 11159
      3346 11152 3347 11146
TIME...MOT...LOC 0319Z 121DEG 12KT 3325 11134

CK

Special weather statement, Jul 20, 8:56 PM MST, 2 hours 55 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
856 PM MST Tue Jul 20 2021

AZZ548-549-551>553-555-558-210445-
Fountain Hills/East Mesa AZ-Northwest Pinal County AZ-East Valley AZ-
Southeast Valley/Queen Creek AZ-Apache Junction/Gold Canyon AZ-
Superior AZ-Pinal/Superstition Mountains AZ-
856 PM MST Tue Jul 20 2021

...SIGNIFICANT WEATHER ADVISORY FOR MARICOPA AND PINAL COUNTIES UNTIL
945 PM MST...

At 855 PM MST, Doppler radar was tracking a strong thunderstorm near
Florence Junction, or near Gold Canyon, moving northwest at 10 mph.

Wind gusts up to 50 mph will be possible with this storm.

Locations impacted include...
Mesa, Gilbert, Apache Junction, East Mesa, Gold Canyon, Queen Creek,
Chandler Heights, Gold Camp, Lost Dutchman State Park, Goldfield,
Usery Mountain Park, Superstition Springs Mall, Magma, San Tan
Village Mall, San Tan Valley, Seville, Superstition Mountains, Kings
Ranch, Phoenix Mesa Gateway Airport and San Tan Mountain Park.

This includes the following highways...
US Highway 60 between mile markers 187 and 211.
AZ Route 202 between mile markers 25 and 43.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3347 11146 3335 11131 3318 11137 3310 11147
      3314 11166 3329 11177 3344 11170 3352 11151
TIME...MOT...LOC 0355Z 128DEG 9KT 3329 11140

Iniguez

Special weather statement, Jul 20, 11:51 PM 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
Jul 20, 5:15 PM MST	Special Weather Statement	PSR	La Paz	45 min
Jul 20, 5:21 PM MST	Special Weather Statement	PSR	Gila	39 min
Jul 20, 5:32 PM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Jul 20, 6:22 PM MST	Special Weather Statement	PSR		38 min
Jul 20, 7:22 PM MST	Special Weather Statement	PSR	Pinal	53 min
Jul 20, 8:19 PM MST	Special Weather Statement	PSR	Pinal	41 min
Jul 20, 8:56 PM MST	Special Weather Statement	PSR	Pinal	49 min
Jul 21, 2:21 AM MST	Flash Flood Watch	PSR	Gila, Maricopa, Pinal	5 days
Jul 21, 8:12 AM MST	Blowing Dust Advisory	PSR	La Paz, Maricopa, Yuma	12 hr
Jul 21, 2:45 PM MST	Special Weather Statement	PSR		45 min
Jul 21, 2:46 PM MST	Dust Storm Warning	PSR	Pinal	40 min
Jul 21, 3:07 PM MST	Special Weather Statement	PSR		38 min
Jul 21, 3:34 PM MST	Special Weather Statement	PSR	Maricopa	41 min
Jul 21, 3:37 PM MST	Special Weather Statement	PSR	La Paz	38 min
Jul 21, 3:42 PM MST	Special Weather Statement	PSR	Yuma	48 min
Jul 21, 3:45 PM MST	Special Weather Statement	PSR	Maricopa	45 min
Jul 21, 3:46 PM MST	Special Weather Statement	PSR		29 min
Jul 21, 3:51 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Jul 21, 3:53 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	37 min
Jul 21, 3:55 PM MST	Special Weather Statement	PSR	Maricopa	50 min
Jul 21, 4:01 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	29 min
Jul 21, 4:11 PM MST	Special Weather Statement	PSR	La Paz	49 min
Jul 21, 4:26 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Jul 21, 4:28 PM MST	Special Weather Statement	PSR	Maricopa	47 min
Jul 21, 4:32 PM MST	Special Weather Statement	PSR		28 min
Jul 21, 4:55 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz	4 hr
Jul 21, 4:59 PM MST	Special Weather Statement	PSR		46 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.