Alert archive / Utah / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 56, NWS Salt Lake City, UT

July 29, 1998Box Elder County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Jul 29, 1998, 2:28 PM MDT for Box Elder County, Utah. It was in force for 47 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 29, 1998, 2:28 PM MDT (20:28 UTC)
Expired
Jul 29, 1998, 3:15 PM MDT
In force
47 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), 123 km from the middle of the area, began a volume at 20:31 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

Elko, NV (KLKN), launched 12:00Z, 8.5 hours before the alert went out and 116 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, Elko, NV at 12:00Z on 1998-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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, Elko, NV at 12:00Z on 1998-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 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
2 J/kg
Mixed-layer CIN
-275 J/kg
Mixed-layer LCL
2521 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
16 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.

118 
WUUS1 KSLC 292030 RRA
SVRSLC
UTC003-292115-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
228 PM MDT WED JUL 29 1998

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

   * SEVERE THUNDERSTORM WARNING FOR...
     EXTREME NORTHWESTERN BOX ELDER COUNTY IN UTAH
     INCLUDING PARK VALLEY

   * UNTIL 315 PM MDT

   * AT 219 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED  
     AN AREA OF SEVERE THUNDERSTORMS 11 MILES SOUTHWEST OF YOST...OR  
     ABOUT 15 MILES WEST OF PARK VALLEY...MOVING NORTH AT 5 MILES    
     PER HOUR 

THIS IS AN EXTENSION OF THE PREVIOUS SEVERE THUNDERSTORM WARNING FOR 
EXTREME NORTHWEST BOX ELDER COUNTY.

VERY LARGE HAIL IS POSSIBLE WITH THIS SEVERE THUNDERSTORM. IF YOU ARE
IN THE PATH OF THE STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A
SUBSTANTIAL SHELTER.

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH YOU SHOULD PREPARE
FOR DAMAGING WINDS IN EXCESS OF 55 MPH...LARGE HAIL...AND DEADLY
LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...PREFERABLY
INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN SALT LAKE CITY.

LAT...LON 4175 11403 4177 11324 4198 11321 4198 11403

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 1:56 PM MDTSevere Thunderstorm WarningSLCBox Elder34 min
Jul 29, 3:08 PM MDTFlash Flood WarningSLCBox Elder82 min
Jul 29, 3:29 PM MDTSevere Thunderstorm WarningSLCBox Elder46 min
Jul 29, 4:44 PM MDTSevere Thunderstorm WarningSLCBox Elder31 min
Jul 29, 5:20 PM MDTSevere Thunderstorm WarningSLCBox Elder40 min

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.