Alert archive / Utah / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 9, NWS Salt Lake City, UT

May 21, 1998Box Elder County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at May 21, 1998, 1:24 PM MDT for Box Elder County, Utah. It was in force for 51 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
May 21, 1998, 1:24 PM MDT (19:24 UTC)
Expired
May 21, 1998, 2:15 PM MDT
In force
51 min
Issued by
NWS Salt Lake City, UT
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Box Elder County, UT

The radar

The Salt Lake City radar (KMTX), 25 km from the middle of the area, began a volume at 19:27 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

Salt Lake City I, UT (KSLC), launched 12:00Z, 7.4 hours before the alert went out and 74 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, Salt Lake City I, UT at 12:00Z on 1998-05-21Temperature 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, Salt Lake City I, UT at 12:00Z on 1998-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 square meters per square second.19395878Sfc1 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
1006 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
24 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.

065 
WUUS1 KSLC 211929 RRA
SVRSLC
UTC003-212015-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
124 PM MDT THU MAY 21 1998

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

   * SEVERE THUNDERSTORM WARNING FOR...
     EAST CENTRAL BOX ELDER COUNTY IN UTAH
     INCLUDING BRIGHAM CITY

   * UNTIL 215 PM MDT

   * AT 117 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
     SEVERE THUNDERSTORM 15 MILES WEST OF WILLARD...OR ABOUT 19 MILES
     NORTHWEST OF OGDEN...MOVING NORTHEAST AT 20 MILES PER HOUR.

   * OTHER LOCATIONS IN THE WARNING INCLUDE PERRY...CORINNE AND
     WILLARD

   * SEVERE THUNDERSTORM WILL BE...
          9 MILES WEST OF WILLARD AT 135 PM MDT
     7 MILES WEST OF PERRY AT 145 PM MDT
     3 MILES WEST OF BRIGHAM CITY AT 200 PM MDT

LARGE HAIL AND STRONG WINDS IN EXCESS OF 57 MPH CAN BE EXPECTED 
WITH THIS STORM.

LAT...LON 4131 11236 4130 11234 4140 11192 4170 11207

ERC...1927Z

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.