Alert archive / Utah / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 52, NWS Salt Lake City, UT

July 21, 1998Washington County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Jul 21, 1998, 5:10 PM MDT for Washington County, Utah. It was in force for 50 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 21, 1998, 5:10 PM MDT (23:10 UTC)
Expired
Jul 21, 1998, 6:00 PM MDT
In force
50 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), 58 km from the middle of the area, began a volume at 23:09 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, 11.2 hours before the alert went out and 246 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 1998-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 122 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 1998-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -20 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
122 J/kg
Mixed-layer CIN
-198 J/kg
Mixed-layer LCL
2317 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
-5 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.

917 
WUUS1 KSLC 212311 RRA
SVRSLC
UTC053-220000-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
510 PM MDT TUE JUL 21 1998

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

   * SEVERE THUNDERSTORM WARNING FOR...
     CENTRAL AND SOUTHEASTERN WASHINGTON COUNTY

   * UNTIL 600 PM MDT

   * AT 505 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED  
SEVERE THUNDERSTORMS ALONG A LINE EXTENDING FROM PINTO JUNCTION TO 
ZION NATIONAL PARK MOVING SOUTH AT 5 MPH.

   * LOCATIONS IN THE WARNING INCLUDE WASHINGTON...     
TOQUERVILLE...SPRINGDALE...HURRICANE AND ZION NP

THESE STORMS WILL PRODUCE LARGE HAIL AND HEAVY RAINS.

LAT...LON 3734 11368 3713 11352 3700 11290 3732 11291

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 6:53 PM MDTSevere Thunderstorm WarningSLCIron42 min
Jul 21, 2:15 PM MDTSevere Thunderstorm WarningSLCSan Juan45 min
Jul 21, 3:07 PM MDTSevere Thunderstorm WarningSLCKane, Washington38 min
Jul 21, 3:30 PM MDTFlash Flood WarningSLCWashington2 hr
Jul 21, 4:50 PM MDTFlash Flood WarningSLCWashington3 hr
Jul 21, 5:41 PM MDTFlash Flood WarningSLCWashington3 hr

Nearby

Severe Thunderstorm Warnings in Utah, 1998Every severe thunderstorm 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.