Alert archive / Arizona / Flash Flood Warnings in 1999

Flash Flood Warning 31, NWS Tucson, AZ

August 8, 1999Cochise County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 8, 1999, 2:41 PM MST for Cochise County, Arizona. It was in force for 119 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
Aug 8, 1999, 2:41 PM MST (21:41 UTC)
Expired
Aug 8, 1999, 4:40 PM MST
In force
119 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), 122 km from the middle of the area, began a volume at 21:44 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, 9.7 hours before the alert went out and 152 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 1999-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 1999-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -26 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2764 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-26 m²/s²
0-3 km storm-relative helicity
84 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 082143
FFWTUS
AZC003-082340-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
241 PM MST SUN AUG 8 1999

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CHIRICAHUA MOUNTAIN RANGE IN EAST-CENTRAL COCHISE COUNTY.

* UNTIL 440 PM MST

* AT 235 PM MST...WEATHER SERVICE DOPPLER RADAR INDICATED VERY HEAVY 
  RAIN OVER THE CHIRICAHUA MOUNTAINS IN EAST-CENTRAL COCHISE COUNTY. 
  THUNDERSTORMS WILL CONTINUE TO DEVELOP OVER THE AREA THROUGH 430   
  PM MST. 

EXCESSIVE RUNOFF FROM THESE STORMS WILL CAUSE FLASH FLOODING OF CREEKS
AND STREAMS...ROADS AND ROADSIDE CULVERTS. THE HEAVY RAINS COULD ALSO
TRIGGER ROCK OR MUDSLIDES IN STEEP TERRAIN.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
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 3161 10946 3163 10918 3206 10919 3202 10946

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 8, 2:00 PM MST, 41 minutes earlier.

Area forecast discussion, Aug 8, 2:00 PM MST, 41 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
200 PM MST SUN AUG 8 1999

SYNOPSIS...AN AREA OF LOW PRESSURE OFF THE CALIFORNIA COAST WILL
WEAKEN DURING THE NEXT TWO DAYS...ALLOWING MONSOON MOISTURE TO
SPREAD BACK INTO MUCH OF SOUTHEAST ARIZONA BY MONDAY AFTERNOON.
THE AREA OF LOW PRESSURE IS EXPECTED TO MOVE INTO THE GREAT BASIN
DURING THE MIDDLE OF THE WEEK...WHICH SHOULD LEAD TO A DRYING TREND
BY THURSDAY.

DISCUSSION...A FEW THUNDERSTORMS WERE DEVELOPING OVER FAR EASTERN
COCHISE COUNTY AND SOUTH OF DOUGLAS IN MEXICO THIS AFTERNOON. WILL
NEED TO WATCH THE STORMS SOUTH OF THE BORDER THIS EVENING TO SEE HOW
FAR NORTH THEY PROPAGATE. OTHERWISE...EXPECT ISOLATED ACTIVITY
TONIGHT WITH THE BEST CHANCES OF STORMS NEAR THE BORDER AROUND
DOUGLAS AND NEAR THE ARIZONA/NEW MEXICO STATE LINE. LATEST MODELS
CONTINUED TO SHOW AN INCREASE IN MOISTURE OVERNIGHT INTO TUESDAY.
NOT SURE HOW FAR WEST THIS MOISTURE WILL GO WITH THE LOW PRESSURE
TROUGH STILL ANCHORED ALONG THE WEST COAST. WATER VAPOR IMAGERY ALSO
SHOWED AN EASTERLY WAVE MOVING OVER MEXICO WHICH WAS AIDING IN THE
WESTWARD PUSH OF MID AND HIGH LEVEL MOISTURE TODAY. EXPECT THIS WAVE
TO TRIGGER A STORM COMPLEX FARTHER NORTH TONIGHT THAN WHAT OCCURRED
LAST EVENING. THIS SHOULD SET THE STAGE FOR AN UPSWING IN
THUNDERSTORM COVERAGE ON MONDAY INTO TUESDAY. BY WEDNESDAY...MEDIUM
RANGE MODELS EJECT THE LOW PRESSURE SYSTEM OFF THE WEST COAST INTO
THE INTERMOUNTAIN REGION WITH DRIER AIR SPREADING INTO THE STATE. AS
A RESULT...WILL LIKELY SEE A DECREASE IN THUNDERSTORMS BY THURSDAY
WITH A DRY SOUTHWESTERLY FLOW OVER PART OF THE AREA. JD

.TWC...NONE.

In the hours before

Special weather statement, Aug 8, 12:50 PM MST, 1 hour 51 minutes before
AZZ019-029>035-090500-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1250 PM MST SUN AUG 8 1999...THIS PRODUCT IS NOT UPDATED

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

COCHISE             10          15         35         0    N 10
GRAHAM              10          10         10         0    N 10
GREENLEE            20          15         35         0    N 10
TUCSON/ERN PIMA      5           5          0         0   NNE 10
TOHONO OODHAM       0           0          0         0
SOUTHEAST PINAL      0           0          0         0
WESTERN PIMA         0           0          0         0
SANTA CRUZ           5          10          5         0   NNE 10

SYNOPSIS...THE FLOW PATTERN BETWEEN A LOW PRESSURE SYSTEM ALONG
THE WEST COAST AND HIGH PRESSURE OVER TEXAS CONTINUED TO RESULT IN
A SHARP MOISTURE GRADIENT ACROSS SOUTHEASTERN ARIZONA TODAY. THE
AIR MASS FROM TUCSON WESTWARD REMAINED DRY AND WARM ALOFT...WHILE
SIGNS OF AN INCREASE IN MOISTURE WERE TAKING PLACE OUT EAST. LATEST
WEATHER MODELS CONTINUED TO SHOW A GRADUAL NORTHWEST PUSH OF
MOISTURE STARTING THIS EVENING INTO TUESDAY. THIS SHOULD LEAD TO
A DAY-TO-DAY INCREASE IN AREAL COVERAGE OF STORMS MONDAY INTO
POSSIBLY WEDNESDAY.

IN THE MEANTIME...DRIER AND WARMER AIR ALOFT OVER WESTERN AND CENTRAL
PIMA COUNTY WILL LIKELY KEEP STORMS FROM DEVELOPING THERE TODAY.
ISOLATED THUNDERSTORM ACTIVITY IS EXPECTED FROM NEAR TUCSON EASTWARD
WITH THE BEST CHANCE OF STORMS OVER THE MOUNTAINS. THE THREAT
FOR SEVERE WEATHER WILL BE LOW TODAY...WITH LOCALLY HEAVY RAINFALL
BEING THE MAIN CONCERN ACROSS FAR SOUTHERN AND EASTERN SECTIONS.

*****************************************************************
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, Aug 8, 12:50 PM MST, 1 hour 51 minutes before
AZZ019-029>035-090500-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1250 PM MST SUN AUG 8 1999...THIS PRODUCT IS NOT UPDATED

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

COCHISE             10          15         35         0    N 10
GRAHAM              10          10         10         0    N 10
GREENLEE            20          15         35         0    N 10
TUCSON/ERN PIMA      5           5          0         0   NNE 10
TOHONO OODHAM       0           0          0         0
SOUTHEAST PINAL      0           0          0         0
WESTERN PIMA         0           0          0         0
SANTA CRUZ           5          10          5         0   NNE 10

SYNOPSIS...THE FLOW PATTERN BETWEEN A LOW PRESSURE SYSTEM ALONG
THE WEST COAST AND HIGH PRESSURE OVER TEXAS CONTINUED TO RESULT IN
A SHARP MOISTURE GRADIENT ACROSS SOUTHEASTERN ARIZONA TODAY. THE
AIR MASS FROM TUCSON WESTWARD REMAINED DRY AND WARM ALOFT...WHILE
SIGNS OF AN INCREASE IN MOISTURE WERE TAKING PLACE OUT EAST. LATEST
WEATHER MODELS CONTINUED TO SHOW A GRADUAL NORTHWEST PUSH OF
MOISTURE STARTING THIS EVENING INTO TUESDAY. THIS SHOULD LEAD TO
A DAY-TO-DAY INCREASE IN AREAL COVERAGE OF STORMS MONDAY INTO
POSSIBLY WEDNESDAY.

IN THE MEANTIME...DRIER AND WARMER AIR ALOFT OVER WESTERN AND CENTRAL
PIMA COUNTY WILL LIKELY KEEP STORMS FROM DEVELOPING THERE TODAY.
ISOLATED THUNDERSTORM ACTIVITY IS EXPECTED FROM NEAR TUCSON EASTWARD
WITH THE BEST CHANCE OF STORMS OVER THE MOUNTAINS. THE THREAT
FOR SEVERE WEATHER WILL BE LOW TODAY...WITH LOCALLY HEAVY RAINFALL
BEING THE MAIN CONCERN ACROSS FAR SOUTHERN AND EASTERN SECTIONS.

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

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.