Alert archive / Arizona / Flash Flood Warnings in 1998

Flash Flood Warning 48, NWS Tucson, AZ

August 17, 1998Pima County, Pinal County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 17, 1998, 5:00 PM MST for Pima County, Pinal County, Arizona. It was in force for 90 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 17, 1998, 5:00 PM MST (00:00 UTC)
Expired
Aug 17, 1998, 6:30 PM MST
In force
90 min
Issued by
NWS Tucson, AZ
Area
Whole counties

Counties Pima County, AZ, Pinal County, AZ

The nearest sounding before it

Tuscon, AZ (KTUS), launched 00:00Z, 0.0 hours before the alert went out and 73 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 1998-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 107 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 1998-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 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
107 J/kg
Mixed-layer CIN
-196 J/kg
Mixed-layer LCL
2013 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
45 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 172359
FFWTUS
AZC019-021-180130-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
500 PM MST MON AUG 17 1998

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

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

* UNTIL 630 PM MST

* AT 458 PM MST... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAIN FROM JUST WEST OF THE TUCSON
  MOUNTAINS NORTHWARD THROUGH MARANA AND ALONG INTERSTATE 10
  THROUGH RED ROCK... MOVING SLOWLY NORTH.

  RAINFALL OF 1.5 TO 2 INCHES/HOUR HAS BEEN INDICATED BY RADAR
  FROM THESE STORMS. FLASH FLOODING IS LIKELY.

  DRB

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 17, 2:30 PM MST, 2 hours 30 minutes earlier.

Area forecast discussion, Aug 17, 2:30 PM MST, 2 hours 30 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST MON AUG 17 1998

SYNOPSIS...A LOW PRESSURE SYSTEM OVER WESTERN ARIZONA WILL GRADUALLY
MOVE NORTHEAST TONIGHT AS HIGH PRESSURE REMAINS NEAR THE FOUR
CORNERS REGION. AS THIS LOW PRESSURE SYSTEM MOVES NORTHEAST...THE
WIND FLOW WILL INCREASE FROM THE SOUTH-SOUTHEAST BRINGING MORE
MOISTURE NORTHWARD FROM MEXICO INTO SOUTHEAST ARIZONA. THIS INFLUX
IN MOISTURE WILL RESULT IN MORE WIDESPREAD AFTERNOON AND EVENING
THUNDERSTORMS THE NEXT FEW DAYS.

DISCUSSION...WATER VAPOR IMAGERY SHOWED UPPER LOW NEAR BLYTHE MOVING
SLOWLY TO THE NORTH-NORTHEAST. 12Z MODELS TREATED THIS FEATURE MUCH
DIFFERENT THAN 24 HOURS AGO SPECIFICALLY IN ITS MOVEMENT. INSTEAD
OF MOVING SLOWLY ESE IT IS NOW PROGGED TO MOVE NE.

EARLIER THIS MORNING I THOUGHT THAT THE AREA FROM TUCSON WEST WILL
BE UNDER THE BEST THREAT FROM FLASH FLOODING DUE TO HIGH
PRECIPITABLE WATER VALUES SEEN ON SOUNDER DATA AND TUCSON/PHOENIX
12Z SOUNDING. WATER VAPOR IMAGERY SHOWING SUBSIDENCE OVER WESTERN
AND CENTRAL PIMA COUNTY WHICH HAS SHIFTED THREAT OF FLASH FLOODING
FROM TUCSON EAST. WITH SOUTHERLY FLOW ALOFT THREAT OF STORMS IS TO
TRAIN THUS ISSUED FLASH FLOOD WATCH EARLIER THIS AFTERNOON UNTIL
9 PM. 12Z ETA THE BEST MODEL AND FORECAST IS BASED ON IT. LIKELY TO
SEE SOME ACTION GOING OVERNIGHT AND HAVE WORDED THE FORECAST THIS
WAY. EXPECT ONLY ISOLATED ACTIVITY CENTRAL/WESTERN PIMA COUNTY.

WILL CONTINUE STANDARD MONSOON FORECAST TUESDAY AND WEDNESDAY WITH
NO CHANGE SEEN FOR THE REMAINDER OF THE WORK WEEK. WILL HAVE TO
WATCH UPPER FEATURE DOWN BY GUYMAS WHICH ETA MOVES A PIECE OF IT
NORTH OVER SE AZ DURING PEAK HEATING TIME TUESDAY. AFTERNNOON
TEMPERATURES WILL BE A FUNCTION OF PREVIOUS NIGHTS ACTIVITY AND HAVE
FORECAST TEMPERATURES SLIGHTLY BELOW NGM MOS. TUS 5232. GLUECK

.TWC...NONE.

In the hours before

Special weather statement, Aug 17, 12:45 PM MST, 4 hours 15 minutes before
AZZ019-029>035-180700-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST MON AUG 17 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          30          50         25      NW 10
GRAHAM           50          30          50         15      NW 10
GREENLEE         40          10          30          5      NW 10
TUCSON/ERN PIMA  50          30          50         25      N 10
TOHONO OODHAM   40          25          40         20      N 10
WESTERN PIMA     20          20          20         10      NE 10
SOUTHEAST PINAL  30          30          40         25      N 10
SANTA CRUZ       60          30          50         30      N 10

SYNOPSIS...MOISTURE CONTINUES TO STREAM NORTH ACROSS THE AREA WITH
THE ATMOSPHERE MORE UNSTABLE THAN SUNDAY. AN UPPER LEVEL DISTURBANCE
NEAR BLYTHE CONTINUES TO MOVE SLOWLY NORTHEAST. HIGH PRECIPITABLE
WATER VALUES WILL LEAD TO HEAVY RAINFALL WITH SOME STORMS AND THE
THREAT OF TRAINING STORMS EXISTS AS THEY MOVE GENERALLY NORTH WHICH
MAY LEAD TO FLASH FLOODING.
*****************************************************************
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/
Special weather statement, Aug 17, 12:45 PM MST, 4 hours 15 minutes before
AZZ019-029>035-180700-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST MON AUG 17 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          30          50         25      NW 10
GRAHAM           50          30          50         15      NW 10
GREENLEE         40          10          30          5      NW 10
TUCSON/ERN PIMA  50          30          50         25      N 10
TOHONO OODHAM   40          25          40         20      N 10
WESTERN PIMA     20          20          20         10      NE 10
SOUTHEAST PINAL  30          30          40         25      N 10
SANTA CRUZ       60          30          50         30      N 10

SYNOPSIS...MOISTURE CONTINUES TO STREAM NORTH ACROSS THE AREA WITH
THE ATMOSPHERE MORE UNSTABLE THAN SUNDAY. AN UPPER LEVEL DISTURBANCE
NEAR BLYTHE CONTINUES TO MOVE SLOWLY NORTHEAST. HIGH PRECIPITABLE
WATER VALUES WILL LEAD TO HEAVY RAINFALL WITH SOME STORMS AND THE
THREAT OF TRAINING STORMS EXISTS AS THEY MOVE GENERALLY NORTH WHICH
MAY LEAD TO FLASH FLOODING.
*****************************************************************
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/

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 6:29 PM MSTFlash Flood WarningTWCPima, Pinal61 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.