Alert archive / Arizona / Flash Flood Warnings in 1998

Flash Flood Warning 6, NWS Tucson, AZ

July 4, 1998Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 4, 1998, 6:31 PM MST for Pima 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 counties it named.

The facts

Issued
Jul 4, 1998, 6:31 PM MST (01:31 UTC)
Expired
Jul 4, 1998, 8:30 PM MST
In force
119 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 01:31 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, 1.5 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 00:00Z on 1998-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 428 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 1998-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 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
428 J/kg
Mixed-layer CIN
-138 J/kg
Mixed-layer LCL
2020 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
-15 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 050133
FFWTUS
AZC019-050330-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
631 PM MST SAT JUL 4 1998

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

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

* UNTIL 830 PM MST

* AT 625 PM MST... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
A THUNDERSTORM WITH VERY HEAVY RAIN OCCURRING ACROSS CENTRAL PIMA
COUNTY FROM 20 MILES SOUTHWEST OF CELLS NORTH TO COVERED WELLS
ALONG HIGHWAY 86 THEN NORTH TO 10 MILES NORTHWEST OF SANTA ROSA.
DOPPLER RADAR INDICATED NEARLY 3 INCHES OF RAIN HAS FALLEN ACROSS
PARTS OF THIS AREA WITHIN THE LAST FEW HOURS.

PERSONS TRAVELING ALONG HIGHWAY 86 BETWEEN SELLS AND AJO SHOULD USE
EXTREME CAUTION AS WASHES SHOULD FILL RAPIDLY WITHIN THE NEXT HOUR.
ALSO FLOODING ON THE WASHES NEAR VAMORI...COWLIC...AND PISINEMO IS
POSSIBLE.



  VPH

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 4, 2:30 PM MST, 4 hours 1 minute earlier.

Area forecast discussion, Jul 4, 2:30 PM MST, 4 hours 1 minute before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST SAT JUL 4 1998

SYNOPSIS...AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BUILD OVER
SOUTHERN AND CENTRAL ARIZONA. FLOW ALOFT WILL BECOME MORE
SOUTHEASTERLY. THIS WILL REGENERATE AFTERNOON AND EVENING
THUNDERSTORM ACTIVITY THROUGH MONDAY.

DISCUSSION...AREAS THAT HAD SIGNIFICANT CLOUD COVER THIS MORNING
SHOWING LITTLE THUNDRESTORM ACTIVITY SO FAR. WILL DROP THESE AREAS
FROM SCATTERED TO ISOLATED FOR THIS EVENING.  MODEL MOISTURE FIELDS
ARE OF LITTLE USE. AT 500 MB THE RIDGE BEGINS BUILDING OVER
SOUTHEAST ARIZONA ON SUNDAY...AND BY MONDAY THE AVN HAS IT NORTH OF
TUCSON. THE 6-10 AVERAGE HAS THE HIGH CENTER NEAR THE FOUR CORNERS
AREA. NO STRONG SURFACE WINDS TO BLOW OUT THE MOISTURE. SO ISOLATED
THUNDERSTORMS WEST AND SCATTERED EAST. AFTERNOON TEMPERATURES WILL
DEPEND ON CLOUD COVER. SO GOING WITH STANDARD MONSOON FORECAST
THROUGH 5 DAYS.

TUS 3222.

4.TWC...NONE.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 4, 6:02 PM MSTSevere Thunderstorm WarningTWCPima48 min
Jul 5, 7:46 AM MSTFlash Flood WarningTWCCochise119 min
Jul 5, 7:57 AM MSTFlash Flood WarningTWCPima2 hr

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.