Alert archive / Arizona / Flash Flood Warnings in 1999

Flash Flood Warning 18, NWS Tucson, AZ

July 23, 1999Cochise County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 23, 1999, 6:34 PM MST for Cochise County, Arizona. It was in force for 86 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 23, 1999, 6:34 PM MST (01:34 UTC)
Expired
Jul 23, 1999, 8:00 PM MST
In force
86 min
Issued by
NWS Tucson, AZ
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Cochise County, AZ

The radar

The Tucson radar (KEMX), 141 km from the middle of the area, began a volume at 01:38 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, 1.6 hours before the alert went out and 161 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 1999-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 157 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 1999-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 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
157 J/kg
Mixed-layer CIN
-147 J/kg
Mixed-layer LCL
1387 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
63 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 240134
FFWTUS
AZC003-240300-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
634 PM MST FRI JUL 23 1999

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN COCHISE COUNTY IN ARIZONA

* UNTIL 800 PM MST

* AT 623 PM MST...WEATHER SERVICE DOPPLER RADAR INDICATED VERY HEAVY 
RAIN OVER NORTHEASTERN COCHISE COUNTY AROUND THE SAN SIMON AREA AND 
ALONG INTERSTATE 10 FROM SAN SIMON TO THE ARIZONA AND NEW MEXICO 
STATE LINE.   

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL 
CREEKS...STREAMS...AND PARTS OF INTERSTATE 10. ADDITIONALLY... 
COUNTRY ROADS AND LOW LYING AREAS ARE SUBJECT TO FLASH FLOODING.

NOTE...THIS FLASH FLOOD WARNING REPLACES THE URBAN AND SMALL STREAM 
FLOOD ADVISORY ISSUED EARLIER THIS EVENING.

LAT...LON 3240 10910 3209 10905 3209 10936 3232 10936

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 23, 2:18 PM MST, 4 hours 16 minutes earlier.

Area forecast discussion, Jul 23, 2:18 PM MST, 4 hours 16 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
218 PM MST FRI JUL 23 1999

SYNOPSIS...A TROUGH OF LOW PRESSURE MOVING WEST ACROSS THE AREA WILL
CONTINUE TO IGNITE THUNDERSTORMS THIS EVENING...SOME OF WHICH WILL
PRODUCE TORRENTIAL DOWNPOURS. AS THIS TROUGH GRADUALLY DISSIPATES ON
SATURDAY...RAINFALL WILL BECOME MORE SPOTTY. HOWEVER...PLENTY OF
MONSOON MOISTURE REMAINS IN PLACE...AND WITH A HIGH PRESSURE CENTER
DEVELOPING OVER THE FOUR-CORNERS BY MONDAY...THUNDERSTORM COVERAGE
WILL ONCE AGAIN INCREASE EARLY NEXT WEEK.

DISCUSSION...AS SOON AS WE HIT OUR CONVECTIVE TEMP, THINGS EXPLODED
ALONG THE SHEAR AXIS EXTENDING FROM N CENTRAL NM INTO SE AZ. THE
MAJORITY OF THE CELLS ARE STILL ELEVATED, BUT THAT WONT LAST LONG
BASED ON THE TOWERING CU FORMING OVER THE TUCSON VALLEY AND TEMPS IN
THE LOWER 90S. HAVE ALREADY HAD MOUNTAIN-HUGGERS DUMP 2-3 RAINS
ACCORDING TO DOPPLER ESTMATES. COMPARING WEAKER CELLS TO OUR ALERT
GAGES, THOSE ESTIMATES ARE PROBABLY CLOSE. DONT LIKE THE -65C TOPS
ORGANIZING ON THE RIM AND DRIFTING SW INTO INCREASINGLY UNSTABLE
AIR. COULD SEE AN ISOLATED CELL OR TWO GIVEN CAPES AROUND 2000J/KG,
BUT WITHOUT MUCH ADDITIONAL HEATING TO DRY OUT AND COMPLETELY MIX
THE BOUNDARY LAYER, THINK ANY OCCURRENCE WILL BE ISOLATED. WITH BEST
MOISTURE CONVERGENCE NOT EXPECTED UNTIL THE 00Z-06Z TIME FRAME,
FLASH FLOOD WATCH WE ISSUED JUST AFTER 100PM WILL RUN A LITTLE LATER
THAN USUAL. THE PAST 2 NIGHTS HAVE FEATURED SOME PATCHY BUT RATHER
DENSE FOG IN THE EASTERN VALLEYS. CANT SEE WHY WE WONT HAVE A
REPEAT TONIGHT AFTER THIS EVENINGS RAIN.

WISH I COULD NAIL DOWN AN ISOLATED VERSUS SCATTERED DAY EITHER
TOMORROW OR SUNDAY, BUT EVEN THE DRIEST AVN KEEP THE EASTERN CWA IN
THE SOUP. THINK THAT THE VERY WET NGM, THOUGH, IS A LITTLE TOO WET
WITH AT LEAST A LITTLE DRIER SW FLOW BEING CARRIED INTO NW AZ AS THE
SHORT WAVE OFF THE SW OREGON COAST LIFTS INLAND. ASSUMING A BIG
EVENING, WE SHOULD HAVE A DOWN DAY TOMORROW GIVEN OUR WEAK LOW LEVEL
FLOW. SUNDAY COULD BE EVEN MORE DOWN, BUT ALL MODELS REFORM THE
4-CORNER HIGH DURING THE DAY AND SWITCH OUR FLOW BACK TO THE SE IN
THE 500-300MB LAYER. THUS IM FORCED INTO A SCATTERED-AD INFINITUM
FORECAST. TEMPS ARE TOUGH WITH CONVECTIVE DEBRIS POSSIBLY SETTING US
BACK ON HIGHS. WELL GO A HAIR WARMER ON SUNDAY ASSUMING A SLIGHTLY
DRIER AIRMASS, BUT STILL WELL BELOW THE NGM/FAN NUMBERS.

MOST MODELS AGREE THAT 4-CORNER HIGH WILL BE WITH US MUCH OF NEXT
WEEK. WELL HAVE TO WATCH THE NEXT LOW OFF THE ALEUTIANS, WHICH A
COUPLE OF SOLUTIONS BRING ROBUSTLY INTO THE WEST COAST. THAT WOULD
WEAKEN THE RIDGE AND DOWNSHIFT THE MONSOON, AT LEAST A LITTLE.
PYTLAK

.TWC...FLASH FLOOD WATCH UNTIL 1000 PM ZONES 19/ERN 29/30/33/34/35.

In the hours before

Special weather statement, Jul 23, 1:19 PM MST, 5 hours 15 minutes before
PHXSPSTUS
TTAA00 KTUS DDHHMM

AZZ019-029>035-240500-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST FRI JUL 23 1999...THIS PRODUCT IS NOT UPDATED

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

COCHISE             65          25         95        30     WNW10
GRAHAM              65          25         90        30     WNW10
GREENLEE            65          15         65        25     WNW10
TUCSON/ERN PIMA     60          25         85        30     W10
TOHONO OODHAM      45          20         50        20     SW10
SOUTHEAST PINAL     55          20         70        30     W10
WESTERN PIMA        25          10         25         5     SW10
SANTA CRUZ          65          30         90        30     W10

SYNOPSIS...VERY MOIST AIR MASS OVER SOUTHEAST ARIZONA. INVERTED TROUGH
EXTENDING NORTH INTO ARIZONA ALONG THE NEW MEXICO BORDER AT NOON
WILL MOVE WEST THROUGH THE DAY TODAY. MORNING CLOUDS OVER NEARLY ALL
SOUTHEAST ARIZONA DELAYING STRONG CONVECTION. CLEARING FROM EAST TO
WEST AS THE INVERTED TROUGH MOVES THROUGH WILL ALLOW STRONGER STORMS
TO DEVELOP THROUGH THE AFTERNOON INTO THE EVENING. STRONGEST STORMS
WITH HEAVIEST RAIN LIKELY LATE AFTERNOON AND INTO THE EVENING.

*****************************************************************
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/
Special weather statement, Jul 23, 1:19 PM MST, 5 hours 15 minutes before
PHXSPSTUS
TTAA00 KTUS DDHHMM

AZZ019-029>035-240500-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST FRI JUL 23 1999...THIS PRODUCT IS NOT UPDATED

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

COCHISE             65          25         95        30     WNW10
GRAHAM              65          25         90        30     WNW10
GREENLEE            65          15         65        25     WNW10
TUCSON/ERN PIMA     60          25         85        30     W10
TOHONO OODHAM      45          20         50        20     SW10
SOUTHEAST PINAL     55          20         70        30     W10
WESTERN PIMA        25          10         25         5     SW10
SANTA CRUZ          65          30         90        30     W10

SYNOPSIS...VERY MOIST AIR MASS OVER SOUTHEAST ARIZONA. INVERTED TROUGH
EXTENDING NORTH INTO ARIZONA ALONG THE NEW MEXICO BORDER AT NOON
WILL MOVE WEST THROUGH THE DAY TODAY. MORNING CLOUDS OVER NEARLY ALL
SOUTHEAST ARIZONA DELAYING STRONG CONVECTION. CLEARING FROM EAST TO
WEST AS THE INVERTED TROUGH MOVES THROUGH WILL ALLOW STRONGER STORMS
TO DEVELOP THROUGH THE AFTERNOON INTO THE EVENING. STRONGEST STORMS
WITH HEAVIEST RAIN LIKELY LATE AFTERNOON AND INTO THE EVENING.

*****************************************************************
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/

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 24, 3:45 PM MSTSevere Thunderstorm WarningTWCPima45 min
Jul 24, 4:09 PM MSTFlash Flood WarningTWCPima81 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.