Alert archive / Arizona / Flash Flood Warnings in 1998

Flash Flood Warning 43, NWS Tucson, AZ

August 11, 1998Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 11, 1998, 5:26 PM MST for Pima County, Arizona. It was in force for 64 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
Aug 11, 1998, 5:26 PM MST (00:26 UTC)
Expired
Aug 11, 1998, 6:30 PM MST
In force
64 min
Issued by
NWS Tucson, AZ
Area
Whole counties

County Pima County, AZ

The radar

The Tucson radar (KEMX), 112 km from the middle of the area, began a volume at 00:26 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, 0.4 hours before the alert went out and 84 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 1998-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 736 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 1998-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -46 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
736 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
2717 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
-46 m²/s²
0-3 km storm-relative helicity
13 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 120028
FFWTUS
AZC019-120130-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
526 PM MST TUE AUG 11 1998

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN PIMA COUNTY IN SOUTHERN ARIZONA

* UNTIL 630 PM MST

* AT 526 PM MST... RADAR RAINFALL ESTIMATES AND RAIN GAGES
  INDICATED A THUNDERSTORM WITH VERY HEAVY RAIN NEAR VAIL OR 15
  MILES SOUTHEAST OF DOWNTOWN TUCSON..."MOVING SLOWLY TOWARD THE
  WEST.
JD

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 Aug 11, 2:30 PM MST, 2 hours 56 minutes earlier.

Area forecast discussion, Aug 11, 2:30 PM MST, 2 hours 56 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST TUE AUG 11 1998

SYNOPSIS...PLENTY OF MOISTURE IN SOUTHEAST ARIZONA AND THE
COMBINATION OF THIS MOISTURE AND AFTERNOON HEATING WILL RESULT IN
AFTERNOON AND EVENING THUNDERSTORMS FOR THE NEXT FEW DAYS.

DISCUSSION...STORMS ON MTNS NOW AND QUESTION IS WILL THEY MOVE OFF
OR JUST SIT THERE...BUT WITH MAX TEMP AT TUS NOW NR 100 THINK THERE
WILL BE PLENTY OF ENERGY FOR STORMS TO MOVE INTO VALLEYS. H2 WNDS
ARE NRLY AND THIS WILL BLOW ANVILS TO THE SOUTH WHICH IS USUALLY A
POSITIVE FACTOR. SINCE THIS APPEARS TO BE AN UP DAY WILL FCST A DOWN
DAY ON WED WITH STORMS DEVELOPING MAINLY NR MTNS. DONT SEE MUCH
CHANGE FOR NEXT FEW DAYS AND WILL UPSWING AGAIN THU AND FRI. TUS
6223. HOLBROOK

.TWC...FLASH FLOOD WATCH UNTIL 900 PM MST FOR ZONES 029...031>035.

In the hours before

Special weather statement, Aug 11, 12:14 PM MST, 5 hours 12 minutes before
AZZ019-029>035-110800-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST TUE AUG 11 1998...THIS PRODUCT IS NOT UPDATED

                        *CONDITIONAL*    *CONDITIONAL*
                AREAL    PROBABILITY   RAIN GREATER THAN   STORM
COUNTY        COVERAGE    OF SEVERE     1.00       2.00    MOTION

COCHISE          60          20          40         20      W  10
GRAHAM           30          10          15         10      W  10
GREENLEE         50          10          20         15      W  10
TUCSON/ERN PIMA  70          25          50         30      W  10
TOHONO OODHAM   60          20          40         25      NW 10
WESTERN PIMA     60          20          40         20      NW 10
SOUTHEAST PINAL  60          20          40         25      NW 10
SANTA CRUZ       80          25          60         35      W  10

SYNOPSIS...TUCSON AND PHOENIX SOUNDINGS MORE MOIST TODAY. OUTFLOW
BOUNDARY FROM LAST NIGHTS MEXICAN STORMS ALONG SOUTHERN BORDER WILL
ACT AS FOCUSING MECHANISM. STORMS SHOULD PROPOGATE INTO DESERTS
DURING THE LATE AFTERNOON.
*****************************************************************
KEY...
AREAL COVERAGE - PERCENT OF COUNTY OR AREA THAT WILL EXPERIENCE
                  THUNDERSTORMS
PROB OF SEVERE - THE PROBABILITY THAT ANY ONE OF THE STORMS WILL
                  REACH SEVERE LEVELS (DAMAGING WIND AND/OR
                  LARGE HAIL)
RAIN GRTR THAN - THE PROBABILITY THAT ANY ONE OF THE STORMS WILL
                  PRODUCE RAIN EXCEEDING 1 INCH OR 2 INCHES IN
                  ANY LOCATION
STORM MOTION   - GENERAL DIRECTION TO WHICH THE STORMS WILL
                  LIKELY MOVE AND SPEED IN MPH

NOTE...
VALID TIME IS FROM 12:45 PM TO 12 MIDNIGHT OF THE DAY OF ISSUANCE.
THIS PRODUCT IS NOT TO BE USED IN PLACE OF SEVERE THUNDERSTORM OR
FLASH FLOOD WARNINGS OR WATCHES. THIS PRODUCT IS ONLY USED FOR
OUTLOOK PURPOSES. CORRESPONDING GRAPHICS MAY BE FOUND ON THE NWS
TUCSON INTERNET PAGE AT
HTTP://NIMBO.WRH.NOAA.GOV/TUCSON/SWO/SWO.SHTML

END/VPH

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 5:42 PM MSTSevere Thunderstorm WarningTWCPima48 min
Aug 11, 6:30 PM MSTFlash Flood WarningTWCPima60 min
Aug 11, 6:30 PM MSTSevere Thunderstorm WarningTWCPima45 min
Aug 11, 6:47 PM MSTSevere Thunderstorm WarningTWCPima33 min
Aug 11, 7:05 PM MSTFlash Flood WarningTWCPima60 min
Aug 11, 8:12 PM MSTFlash Flood WarningTWCPima68 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.