Alert archive / Arizona / Flash Flood Warnings in 1998

Flash Flood Warning 31, NWS Tucson, AZ

July 29, 1998Cochise County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 29, 1998, 10:38 PM MST for Cochise County, Arizona. It was in force for 92 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 29, 1998, 10:38 PM MST (05:38 UTC)
Expired
Jul 30, 1998, 12:10 AM MST
In force
92 min
Issued by
NWS Tucson, AZ
Area
Whole counties

County Cochise County, AZ

The radar

The Tucson radar (KEMX), 83 km from the middle of the area, began a volume at 05:41 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 00:00Z, 5.6 hours before the alert went out and 113 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 00:00Z on 1998-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 282 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 00:00Z on 1998-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 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
282 J/kg
Mixed-layer CIN
-110 J/kg
Mixed-layer LCL
2439 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
-1 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, in the capitals the NWS used until 2016.

000 
TTAA00 KTUS 300538
FFWTUS
AZC003-300710-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
1038 PM MST WED JUL 29 1998

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WEST CENTRAL COCHISE COUNTY IN SOUTHEASTERN ARIZONA

* UNTIL 1210 AM MST

* AT 1035 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A THUNDERSTORM WITH VERY HEAVY RAIN ALONG THE EAST SLOPES OF THE
  DRAGOON MOUNTAINS...WITH VERY LITTLE MOVEMENT. FLASH FLOODING
  WILL BE LIKELY NEAR THE CAMPGROUNDS SURROUNDING COCHISE
  STRONGHOLD AND THE TOWN OF PEARCE.

OKULSKI



  OKULSKI

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Tucson, AZ wrote its last area forecast discussion before this flash flood warning went out at Jul 29, 9:30 PM MST, 1 hour 8 minutes earlier.

Area forecast discussion, Jul 29, 9:30 PM MST, 1 hour 8 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
930 PM MST WED JUL 29 1998

SYNOPSIS...SOUTHEAST ARIZONA WILL BE ON THE BOUNDARY BETWEEN MOIST
AND DRY AIRMASSES TONIGHT THROUGH THURSDAY. THE DRY AIR WILL MOVE
INTO THE SOUTHEAST PORTION OF THE STATE FRIDAY AND SATURDAY
DECREASING THE THUNDERSTORM THREAT.

DISCUSSION...THE MONSOON MOISTURE BOUNDARY HAS BEEN PUSHED EASTWARD
THIS EVENING BY A WESTERLY WIND FLOW ALOFT. MOST OF THE RESIDUAL
CONVECTIVE ACTIVITY WAS FROM THE GLOBE AREA SOUTHWARD THROUGH GRAHAM
AND COCHISE COUNTIES AT 9 PM. THE FEATURE OF INTEREST THIS EVENING
WAS A LARGE MESO SCALE CONVECTIVE SYSTEM OVER NORTHERN SONORA.
SHOULD SEE OUTFLOW WINDS AND DEBRIS CLOUDS SPREADING INTO SANTA CRUZ
AND COCHISE COUNTIES TOWARD MIDNIGHT. MAY EVEN SEE ISOLATED
THUNDERSTORMS UNTIL THE EARLY MORNING HOURS NEAR THE MEXICAN BORDER.
WILL UPDATE ZONES FOR CURRENT TRENDS IN THE FIRST PERIOD.

THE TWO SYNOPTIC SYSTEMS OF INTEREST FOR THURSDAY ARE A SUBTROPICAL
UPPER LEVEL LOW PRESSURE SYSTEM SOUTH OF THE BIG BEND AREA OF TEXAS
AND A POLAR UPPER TROUGH MOVING INTO THE PACIFIC NORTHWEST. THE
SUBTROPICAL SYSTEM CONTINUES TO SPREAD DEEP MONSOONAL MOISTURE JUST
TO OUR* SOUTH WHILE THE POLAR TROUGH IS PUSHING DRIER AIR INTO
WESTERN ARIZONA. THE DRY AIR SHOULD WIN OUT OVER TIME...BUT HOW
QUICKLY? THE MIDNIGHT SHIFT WILL HAVE THE JOB OF SORTING OUT THE
DETAILS.

TUS 1442. OKULSKI

.TWC...NONE

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 5:08 PM MSTSevere Thunderstorm WarningTWCCochise47 min
Jul 30, 2:59 PM MSTFlash Flood WarningTWCSanta Cruz2 hr
Jul 30, 4:27 PM MSTFlash Flood WarningTWCCochise, Pima93 min

Nearby

Flash Flood Warnings in Arizona, 1998Every flash flood warning in 1998

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.