Alert archive / Utah / Flash Flood Warnings in 1998

Flash Flood Warning 50, NWS Salt Lake City, UT

September 5, 1998Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Sep 5, 1998, 3:20 PM MDT for Washington County, Utah. It was in force for 85 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
Sep 5, 1998, 3:20 PM MDT (21:20 UTC)
Expired
Sep 5, 1998, 4:45 PM MDT
In force
85 min
Issued by
NWS Salt Lake City, UT
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Washington County, UT

The radar

The Cedar City radar (KICX), 75 km from the middle of the area, began a volume at 21:20 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

Mercury/Desert R, NV (KDRA), launched 12:00Z, 9.3 hours before the alert went out and 226 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, Mercury/Desert R, NV at 12:00Z on 1998-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 919 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, Mercury/Desert R, NV at 12:00Z on 1998-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -29 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
919 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
604 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
-29 m²/s²
0-3 km storm-relative helicity
31 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 KSLC 052123
FFWSLC
UTC053-052245-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
320 PM MDT SAT SEP 5 1998

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

   * FLASH FLOOD WARNING FOR...
     WASHINGTON COUNTY IN UTAH
     INCLUDING ST GEORGE

   * UNTIL 445 PM MDT

   * AT 315 PM MDT WEATHER SERVICE DOPPLER RADAR INDICATED NUMEROUS  
     THUNDERSTORMS WITH VERY HEAVY RAIN OVER AND JUST SOUTH OF       
     WASHINGTON COUNTY...MOVING NORTH AT 25 MILES PER HOUR.

WEATHER SPOTTER AND DOPPLER RADAR RAINFALL ESTIMATES SHOW 
THUNDERSTORMS PRODUCING BETWEEN .75 AND 1.00 INCH OF RAIN IN 30 
MINUTES OR LESS. THESE RAINFALL RATES WILL PRODUCE FLASH FLOODING IN 
NARROW OR STEEP TERRAIN.

TO REPORT FLASH FLOODING HAVE THE NEAREST LAW ENFORCEMENT AGENCY
RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY.
STAY TUNED TO LOCAL TELEVISION...RADIO...CABLE TV...OR NOAA WEATHER
RADIO FOR UPDATES.

LAT...LON 3705 11400 3703 11293 3743 11295 3756 11401

The office that day

Everything else NWS Salt Lake City, UT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 5, 2:14 PM MDTFlash Flood WarningSLCWashington91 min
Sep 5, 3:08 PM MDTFlash Flood WarningSLCKane67 min
Sep 5, 4:16 PM MDTFlash Flood WarningSLCKane, San Juan89 min

Nearby

Flash Flood Warnings in Utah, 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.