Alert archive / Arizona / Flash Flood Warnings in 1997

Flash Flood Warning 17, NWS Phoenix, AZ

September 11, 1997Maricopa County, Pinal County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Sep 11, 1997, 12:50 PM MST for Maricopa County, Pinal County, Arizona. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Sep 11, 1997, 12:50 PM MST (19:50 UTC)
Expired: Sep 11, 1997, 2:50 PM MST
In force: 2 hr
Issued by: NWS Phoenix, AZ
Area: Whole counties

Counties Maricopa County, AZ, Pinal County, AZ

The radar

The Phoenix radar (KIWA), 29 km from the middle of the area, began a volume at 19:52 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

Tuscon, AZ (KTUS), launched 12:00Z, 7.8 hours before the alert went out and 143 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: 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 111950
FFWPHX
AZC013-021-112150-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD AND SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
1250 PM MST THU SEP 11 1997

*  FLASH FLOOD AND SEVERE THUNDERSTORM WARNING FOR
   SOUTHWESTERN MARICOPA COUNTY IN CENTRAL ARIZONA
   NORTHWESTERN PINAL COUNTY IN CENTRAL ARIZONA

*  UNTIL 250 PM MST

*  SOME LOCATIONS AFFECTED
   INTERSTATE 8 ALONG THE MARICOPA/PINAL COUNTY LINE
   TABLE TOP WILDERNESS AREA
 
*  AT 1250 AM MST RADAR DETECTED A SEVERE STORM ALONG INTERSTATE 8
   SOUTHWEST OF STANFIELD.  MOVEMENT WAS TO THE SOUTHEAST AT
   5 MPH. IN ADDITION...RADAR ESTIMATED RAINFALL RATES OF TWO
   INCHES IN THE PAST HOUR.  THUS... FLASH FLOODING IS OCCURRING
   OR IMMINENT WITH THESE STORMS.

DAMAGING WINDS IN EXCESS OF 60 MPH ARE LIKELY WITH THIS STORM.
 
MB

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 11, 10:25 AM MST	Severe Thunderstorm Warning	PSR	Maricopa	45 min
Sep 11, 10:43 AM MST	Severe Thunderstorm Warning	PSR	Maricopa	62 min
Sep 11, 11:48 AM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	62 min
Sep 11, 12:50 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	2 hr
Sep 11, 1:13 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	57 min

Nearby

Flash Flood Warnings in Arizona, 1997 Every flash flood 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.