Alert archive / Arizona / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 99, NWS Phoenix, AZ

September 11, 1997Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Sep 11, 1997, 10:43 AM MST for Maricopa County, Arizona. It was in force for 62 min. 3 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Sep 11, 1997, 10:43 AM MST (17:43 UTC)
Expired
Sep 11, 1997, 11:45 AM MST
In force
62 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 77 km from the middle of the area, began a volume at 17:47 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

TimeReportWhereRemark
Sep 11, 10:47 AM MSTThunderstorm Wind 50Phoenix, AZSpotters reported trellises and shingles damaged in North Phoenix.
Sep 11, 11:00 AM MSTThunderstorm Wind 52Phoenix, AZNWS employee estimated wind gusts to 60 mph.
Sep 11, 11:02 AM MSTThunderstorm Wind 80Phoenix, AZDeer Valley airport reported a peak gust of 92mph.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Tuscon, AZ (KTUS), launched 12:00Z, 5.7 hours before the alert went out and 198 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-pSkew-T log-p diagram, Tuscon, AZ at 12:00Z on 1997-09-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 163 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tuscon, AZ at 12:00Z on 1997-09-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -6 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
163 J/kg
Mixed-layer CIN
-200 J/kg
Mixed-layer LCL
2343 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-6 m²/s²
0-3 km storm-relative helicity
59 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KPHX 111743 RRA
SVRPHX
AZC013-111845-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
1043 AM MST THU SEP 11 1997


*  SEVERE THUNDERSTORM WARNING FOR
   NORTHWESTERN AND NORTH CENTRAL MARICOPA COUNTY IN CENTRAL ARIZONA

*  UNTIL 1145 AM MST

*  SOME LOCATIONS AFFECTED
   WICKENBURG
   MORRISTOWN
   NEW RIVER
   LAKE PLEASANT
   SURPRISE
   NORTH PHOENIX

*  AT 1042 AM MST RADAR INDICATED SEVERE THUNDERSTORMSZ
   FROM WICKENBURG TO NEAR SURPRISE AND NORTH OF SUN CITY. MOVEMENT
   WAS TO THE NORTHEAST AT 20 MPH.

STRONG DAMAGING WINDS ARE LIKELY WITH THESE STORMS.

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 11, 10:25 AM MSTSevere Thunderstorm WarningPSRMaricopa45 min
Sep 11, 11:48 AM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal62 min
Sep 11, 12:50 PM MSTFlash Flood WarningPSRMaricopa, Pinal2 hr
Sep 11, 12:50 PM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal2 hr
Sep 11, 1:13 PM MSTSevere Thunderstorm WarningPSRMaricopa57 min

Nearby

Severe Thunderstorm Warnings in Arizona, 1997Every severe thunderstorm warning in 1997

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.