Alert archive / Arizona / Flash Flood Warnings in 1998

Flash Flood Warning 35, NWS Tucson, AZ

August 1, 1998Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 1, 1998, 4:21 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 1, 1998, 4:21 PM MST (23:21 UTC)
Expired
Aug 1, 1998, 5:25 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 23:23 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, 11.4 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 12:00Z on 1998-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 197 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 1998-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -7 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
197 J/kg
Mixed-layer CIN
-124 J/kg
Mixed-layer LCL
1780 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
5 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 012322
FFWTUS
AZC019-020025-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
421 PM MST SAT AUG 1 1998

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN PIMA COUNTY IN SOUTHERN ARIZONA...INCLUDING THE TUCSON
  METRO AREA.

* UNTIL 525 PM MST

* AT 415 PM MST... RADAR RAINFALL ESTIMATES AND SPOTTER REPORTS
  INDICATED A THUNDERSTORM WITH VERY HEAVY RAIN OVER SOUTHERN
  TUCSON...MOVING SLOWLY NORTHWEST. A WEATHER SPOTTER AT CRAYCROFT
  AND I-10 REPORTED FLOODED ROADWAYS. RADAR ESTIMATES UP TO 2 INCHES
  OF RAIN HAS FALLEN IN THE PAST HOUR FROM THIS STORM.

CEC

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 1, 2:30 PM MST, 1 hour 51 minutes earlier.

Area forecast discussion, Aug 1, 2:30 PM MST, 1 hour 51 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST SAT AUG 1 1998

SYNOPSIS...MOIST AIR REMAINS OVER THE STATE AND THUNDERSTORMS WILL
DEVELOP DURING THE AFTERNOON AND EVENING.

DISCUSSION...REALLY ACTIVE DAY SO FAR BUT TSTMS STILL HAVNT MOVD FAR
AWAY FROM MTNS...BUT TEMPS SEEM TO BE MOVG UP NICELY SO THINK THEY
WILL MOVE INTO VALLEYS THIS AFTN. ONE THING THAT MIGHT HELP IS THAT
ETA FCST H2 UPR LOW DEVELOPING SOUTH OF SAN PUTTING SRN AZ IN
FAVORABLE SECTION OF LOW.

WOULD NORMALLY FCST DOWN DAY FOR SUN AFTER BIG DAY TODAY BUT THINK
THAT POTENTIAL FOR SWD MOVG RIM STORMS EXISTS SINCE MID LVL WNDS
WILL BECOME NRLY.

DONT SEE MUCH CHANGE IN MSTR INTO NEXT WEEK AND EXCEPT FOR DAY TO
DAY VARIABILITY NOT MUCH TO CHANGE. TUS 7232. HOLBROOK

.TWC...FLASH FLOOD WATCH ZONES 029-032>035 UNTIL 700 PM MST.

In the hours before

Special weather statement, Aug 1, 12:45 PM MST, 3 hours 36 minutes before
AZZ019-029>035-020700-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST SAT AUG 1 1998...THIS PRODUCT IS NOT UPDATED

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

COCHISE          70          15          70         40     N  10
GRAHAM           70          15          70         40     N  10
GREENLEE         60          10          60         30     N  10
TUCSON/ERN PIMA  70          20          70         50     N  10
TOHONO O'ODHAM   60          20          70         50     N  10
WESTERN PIMA     50          15          40         20     N  10
SOUTHEAST PINAL  60          20          70         40     N  10
SANTA CRUZ       70          20          70         60     N  10

SYNOPSIS...PLENTY OF MOISTURE IN PLACE AND STORMS DEVELOPING SOUTH
OF NOGALES SHOULD EXPAND NORTHWARD. SOME THREAT OF SEVERE WINDS WITH
STORMS.
*****************************************************************
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
Jul 31, 5:18 PM MSTSevere Thunderstorm WarningTWCCochise47 min
Jul 31, 5:47 PM MSTFlash Flood WarningTWCCochise78 min
Aug 1, 1:18 PM MSTSevere Thunderstorm WarningTWCSanta Cruz52 min
Aug 1, 3:53 PM MSTSevere Thunderstorm WarningTWCPima47 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.