Alert archive / Arizona / Flash Flood Warnings in 1999

Flash Flood Warning 19, NWS Tucson, AZ

July 24, 1999Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 24, 1999, 4:09 PM MST for Pima County, Arizona. It was in force for 81 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued
Jul 24, 1999, 4:09 PM MST (23:09 UTC)
Expired
Jul 24, 1999, 5:30 PM MST
In force
81 min
Issued by
NWS Tucson, AZ
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Pima County, AZ

The radar

The Tucson radar (KEMX), 46 km from the middle of the area, began a volume at 23:12 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, 11.2 hours before the alert went out and 7 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 1999-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 380 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 1999-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 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
380 J/kg
Mixed-layer CIN
-127 J/kg
Mixed-layer LCL
1266 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
-21 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 KTWC 242309
FFWTUS
AZC019-250030-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
409 PM MST SAT JUL 24 1999

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL PIMA COUNTY IN ARIZONA
  THIS INCLUDES THE CITY OF TUCSON

* UNTIL 530 PM MST

* AT 405 PM MST...WEATHER SERVICE DOPPLER RADAR INDICATED VERY HEAVY
  RAIN OVER PORTIONS OF SOUTH TUCSON. THE HEAVY RAIN WILL SPREAD NORTHWARD 
  ACROSS THE GREATER TUCSON AREA CAUSING FLASH FLOODING. 

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE. IF YOUR VEHICLE STALLS, ABANDON IT IMMEDIATELY AND SEEK
HIGHER GROUND.


LAT...LON 3212 11107 3212 11069 3239 11072 3239 11107

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 24, 2:05 PM MST, 2 hours 4 minutes earlier.

Area forecast discussion, Jul 24, 2:05 PM MST, 2 hours 4 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
205 PM MST SAT JUL 24 1999

SYNOPSIS...HIGH PRESSURE ALOFT WILL SHIFT FROM THE CENTRAL PLAINS
INTO THE FOUR CORNERS AREA BY MONDAY. SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS WILL CONTINUE...BUT THEY WILL BECOME MORE
NUMEROUS AND ORGANIZED BY MONDAY AS A DISTURBANCE MOVES WEST FROM
THE GULF OF MEXICO.

DISCUSSION...COVERAGE HAS BEEN SOMEWHAT SUPPRESSED THIS AFTERNOON,
AT LEAST SO FAR. ENOUGH MID LEVEL DRYING HAS SPREAD INTO COCHISE
COUNTY TO KEEP THE COVERAGE THERE VERY ISOLATED. THAT DRY POCKET,
THOUGH, IS CLOSING UP AS LEADING EDGE OF DEEP GULF OF MEXICO PUSHES
INTO THE SIERRA MADRES. COMBINED WITH WEAK DIVERGENCE ALOFT AND 20KT
SSE FLOW, WE SHOULD GET AN MCS OR MCC THIS EVENING TO OUR SE WITH
ITS REMNANTS PUSHING INTO AREAS THAT MAY MISS THE FIRST ROUND THIS
EVENING. IN ESSENCE, IM GOING TO STICK WITH OUR GOING FORECAST:
SCATTERED STUFF THIS EVENING DIMINISHING TO ISOLATED ANVIL SHOWERS
OVERNIGHT, FOLLOWED BY MOUNTAIN HUGGING AFTERNOON CELLS
TRANSITIONING TO SCATTERED VALLEY STORMS ON SUNDAY. MONDAY LOOKS
LIKE A BIG DAY AS 4-CORNER HIGH GETS INTO POSITION AND DEEP SE-S
FLOW RUNS INTO THE 20KT RANGE. THERES A CHANCE OF AN ACTIVE DAY
TOMORROW SINCE DEEP SE FLOW AND GULF OF MEXICO MOISTURE WILL ALREADY
BE IN PLACE, BUT IT LOOKS LIKE WELL BE MISSING A FOCUSING MECHANISM
UNTIL THE MCS-INDUCED WAVE OFF THE TX COAST MOVES WEST TOWARD OUR
NEIGHBORHOOD. MODELS DO A TERRIBLE JOB WITH IT, SO ILL HAVE TO RELY
ON EXTRAPOLATION. BEST GUESS IS ARRIVAL LATE SUNDAY NIGHT OR MONDAY,
WHICH AGREES WELL WITH UPPER LEVEL RIDGE DEVELOPMENT. GULF SURGE
POTENTIAL WILL BE HIGH OVER THE NEXT SEVERAL DAYS, BUT WITH
DEWPOINTS ALREADY WELL INTO THE 60S, WILL IT REALLY MATTER?
LONGWAVE LOOKS VERY ACTIVE FOR THE UPCOMING WEEK WITH STRIKING
SIMILARITIES TO THE 1ST WEEK OF JULY WHEN WE HAD A DAILY SEVERE
WEATHER/FLASH FLOOD THREAT. THIS IS DEFINITELY NOT A QUIET MONSOON
SEASON THIS YEAR PYTLAK

.TWC...NONE.

In the hours before

Special weather statement, Jul 24, 11:30 AM MST, 4 hours 39 minutes before
AZZ019-029>035-250500-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1130 AM MST SAT JUL 24 1999...THIS PRODUCT IS NOT UPDATED

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

COCHISE             50          20         35        20     NW10
GRAHAM              50          20         35        10     NW10
GREENLEE            60          15         40        10     NW12
TUCSON/ERN PIMA     45          25         40        20     NW10
TOHONO OODHAM      40          30         50        25     NW8
SOUTHEAST PINAL     40          20         40        20     NW10
WESTERN PIMA        35          30         50        25     NW6
SANTA CRUZ          55          20         35        20     NW10

SYNOPSIS...THE ATMOSHPERE REMAINS MOST AND UNSTABLE ACROSS THE
AREA...BUT THERE ARE NO DISTURBANCES TO FOCUS THUNDERSTORM
DEVELOPMENT THIS AFTERNOON OR EVENING. THE DEEPEST MOISTURE WILL
RESIDE WEST OF TUCSON THIS EVENING...WHICH IS WHERE THE THREAT OF
HEAVYU DOWNPOURS WILL BE HIGHEST. STEERING WINDS ARE STRONGER
TODAY WHICH WILL KEEP THE STORMS FROM GETTING STUCK IN ONE PLACE.
HOWEVER THOSE SAME WINDS SHOULD ALLOW STORMS THAT INITIALLY FORM
ON THE MOUNTAINS TO SPREAD INTO THE VALLEYS AND DESERTS BY LATE
AFTERNOON...SOME OF WHICH COULD GET RATHER STRONG. A THUNDERSTORM
COMPLEX MAY FORM SOUTH OF DOUGLAS THIS EVENING WITH ITS REMNANTS
SPILLING NORTH INTO THE AREA LATE TONIGHT.

*****************************************************************
KEY...
AREAL COVERAGE - PERCENT OF COUNTY OR AREA THAT WILL EXPERIENCE
                 THUNDERSTORMS
PROB OF SEVERE - THE PROBABILITY THAT AN INDIVIDUAL STORM WILL
                 REACH SEVERE LEVELS (DAMAGING WIND AND/OR
                 LARGE HAIL)
RAIN GRTR THAN - THE PROBABILITY THAT AN INDIVIDUAL STORM 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/PYTLAK
Special weather statement, Jul 24, 11:30 AM MST, 4 hours 39 minutes before
AZZ019-029>035-250500-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1130 AM MST SAT JUL 24 1999...THIS PRODUCT IS NOT UPDATED

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

COCHISE             50          20         35        20     NW10
GRAHAM              50          20         35        10     NW10
GREENLEE            60          15         40        10     NW12
TUCSON/ERN PIMA     45          25         40        20     NW10
TOHONO OODHAM      40          30         50        25     NW8
SOUTHEAST PINAL     40          20         40        20     NW10
WESTERN PIMA        35          30         50        25     NW6
SANTA CRUZ          55          20         35        20     NW10

SYNOPSIS...THE ATMOSHPERE REMAINS MOST AND UNSTABLE ACROSS THE
AREA...BUT THERE ARE NO DISTURBANCES TO FOCUS THUNDERSTORM
DEVELOPMENT THIS AFTERNOON OR EVENING. THE DEEPEST MOISTURE WILL
RESIDE WEST OF TUCSON THIS EVENING...WHICH IS WHERE THE THREAT OF
HEAVYU DOWNPOURS WILL BE HIGHEST. STEERING WINDS ARE STRONGER
TODAY WHICH WILL KEEP THE STORMS FROM GETTING STUCK IN ONE PLACE.
HOWEVER THOSE SAME WINDS SHOULD ALLOW STORMS THAT INITIALLY FORM
ON THE MOUNTAINS TO SPREAD INTO THE VALLEYS AND DESERTS BY LATE
AFTERNOON...SOME OF WHICH COULD GET RATHER STRONG. A THUNDERSTORM
COMPLEX MAY FORM SOUTH OF DOUGLAS THIS EVENING WITH ITS REMNANTS
SPILLING NORTH INTO THE AREA LATE TONIGHT.

*****************************************************************
KEY...
AREAL COVERAGE - PERCENT OF COUNTY OR AREA THAT WILL EXPERIENCE
                 THUNDERSTORMS
PROB OF SEVERE - THE PROBABILITY THAT AN INDIVIDUAL STORM WILL
                 REACH SEVERE LEVELS (DAMAGING WIND AND/OR
                 LARGE HAIL)
RAIN GRTR THAN - THE PROBABILITY THAT AN INDIVIDUAL STORM 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/PYTLAK
Local storm report, Jul 24, 4:04 PM MST, 5 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
404 PM MST SAT JUL 24 1999

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0359 PM    DAVIS MONTHAN AFB          AZ  WIND GUST OF 94 MPH
7/24/99    EASTERN PIMA

RASMUSSEN
Local storm report, Jul 24, 4:04 PM MST, 5 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
404 PM MST SAT JUL 24 1999

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0359 PM    DAVIS MONTHAN AFB          AZ  WIND GUST OF 94 MPH
7/24/99    EASTERN PIMA

RASMUSSEN

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 23, 6:34 PM MSTFlash Flood WarningTWCCochise86 min
Jul 24, 3:45 PM MSTSevere Thunderstorm WarningTWCPima45 min

Nearby

Flash Flood Warnings in Arizona, 1999Every flash flood warning in 1999

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.