Alert archive / Arizona / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 677

September 7, 20026 counties in Arizona

The Storm Prediction Center issued this severe thunderstorm watch at Sep 7, 2002, 1:30 PM MST for 6 counties in Arizona. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Sep 7, 2002, 1:30 PM MST (20:30 UTC)
Expired: Sep 7, 2002, 8:00 PM MST
In force: 7 hr
Issued by: the Storm Prediction Center

Counties Gila County, AZ, La Paz County, AZ, Maricopa County, AZ, Pima County, AZ, Pinal County, AZ, Yuma County, AZ

The radar

The Yuma radar (KYUX), 128 km from the middle of the area, began a volume at 20:32 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.

Warnings issued inside it

11 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Sep 7, 2:38 PM MST	Severe Thunderstorm Warning	PSR	La Paz	37 min
Sep 7, 2:45 PM MST	Severe Thunderstorm Warning	PSR	Pinal	45 min
Sep 7, 3:14 PM MST	Severe Thunderstorm Warning	PSR	La Paz	46 min
Sep 7, 3:27 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	48 min
Sep 7, 3:57 PM MST	Tornado Warning	PSR	Maricopa	48 min
Sep 7, 3:57 PM MST	Tornado Warning	PSR	Maricopa	48 min
Sep 7, 4:08 PM MST	Severe Thunderstorm Warning	PSR	Pinal	37 min
Sep 7, 4:43 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	47 min
Sep 7, 6:11 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	39 min
Sep 7, 7:05 PM MST	Flash Flood Warning	TWC	Pima	55 min
Sep 7, 7:07 PM MST	Flash Flood Warning	TWC	Pima	113 min

The nearest sounding before it

Phoenix, AZ (KPSR), launched 12:00Z, 8.5 hours before the alert went out and 150 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: 146 J/kg
Mixed-layer CIN: -210 J/kg
Mixed-layer LCL: 1553 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 38 m²/s²
0-3 km storm-relative helicity: 62 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 7, 12:10 PM MST	Severe Thunderstorm Watch	SPC	Coconino, Navajo	8 hr

Nearby

Severe Thunderstorm Watches in Arizona, 2002 Every severe thunderstorm watch in 2002

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.