Alert archive / Arizona / Special Weather Statements in 2021

Special Weather Statement, NWS Phoenix, AZ

July 16, 2021

NWS Phoenix, AZ issued this special weather statement at Jul 16, 2021, 9:48 AM MST. It was in force for 27 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 16, 2021, 9:48 AM MST (16:48 UTC)
Expired: Jul 16, 2021, 10:15 AM MST
In force: 27 min
Issued by: NWS Phoenix, AZ

The radar

The Phoenix radar (KIWA), 14 km from the middle of the area, began a volume at 16:52 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, 4.8 hours before the alert went out and 22 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2375 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 19 m²/s²
0-3 km storm-relative helicity: 52 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 16, 4:54 AM MST, 4 hours 54 minutes earlier.

Area forecast discussion, Jul 16, 4:54 AM MST, 4 hours 54 minutes before

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In the hours before

Special weather statement, Jul 16, 8:54 AM MST, 54 minutes before

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Special weather statement, Jul 16, 9:48 AM MST, 0 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
948 AM MST Fri Jul 16 2021

AZZ548-550-551-553-161715-
South Mountain/Ahwatukee AZ-Northwest Pinal County AZ-East Valley AZ-
Southeast Valley/Queen Creek AZ-
948 AM MST Fri Jul 16 2021

...SIGNIFICANT WEATHER ADVISORY FOR MARICOPA AND PINAL COUNTIES UNTIL
1015 AM MST...

At 947 AM MST, Doppler radar was tracking a strong thunderstorm over
Tumbleweed Park, or near Chandler, moving southwest at 10 mph.

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

Locations impacted include...
Mesa, Chandler, Gilbert, Sun Lakes, Queen Creek, Gilbert City Hall,
Tumbleweed Park, Chandler City Hall, San Tan Village Mall, Seville,
Freestone Park, Bapchule, Chandler Fashion Center Mall, Phoenix Mesa
Gateway Airport, Sacaton, Santan and Higley.

This includes the following highways...
AZ Interstate 10 between mile markers 164 and 177.
US Highway 60 near mile marker 179.
AZ Route 87 between mile markers 151 and 171.

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 3339 11185 3332 11165 3307 11175 3318 11202
TIME...MOT...LOC 1647Z 026DEG 8KT 3326 11182

INS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 15, 5:06 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Jul 15, 5:07 PM MST	Special Weather Statement	PSR		38 min
Jul 15, 5:12 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	48 min
Jul 15, 5:33 PM MST	Special Weather Statement	PSR	La Paz	42 min
Jul 15, 5:43 PM MST	Special Weather Statement	PSR		47 min
Jul 15, 6:00 PM MST	Areal Flood Advisory	PSR	Maricopa, Pinal	3 hr
Jul 15, 6:08 PM MST	Special Weather Statement	PSR	Pinal	52 min
Jul 16, 8:54 AM MST	Special Weather Statement	PSR	Pinal	36 min
Jul 16, 11:21 AM MST	Areal Flood Advisory	PSR	Maricopa	111 min
Jul 16, 2:56 PM MST	Special Weather Statement	PSR	Gila	34 min
Jul 16, 3:27 PM MST	Special Weather Statement	PSR		33 min
Jul 16, 3:37 PM MST	Special Weather Statement	PSR	Gila	38 min
Jul 16, 4:39 PM MST	Special Weather Statement	PSR	Gila	36 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.