Alert archive / Idaho / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 7, NWS Salt Lake City, UT

May 21, 1997Franklin County, Idaho; Cache County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at May 21, 1997, 6:47 PM MDT for Franklin County, Idaho; Cache County, Utah. It was in force for 28 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
May 21, 1997, 6:47 PM MDT (00:47 UTC)
Expired
May 21, 1997, 7:15 PM MDT
In force
28 min
Issued by
NWS Salt Lake City, UT
Area
Whole counties

Counties Franklin County, ID, Cache County, UT

The nearest sounding before it

Salt Lake City I, UT (KSLC), launched 00:00Z, 0.8 hours before the alert went out and 131 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 00:00Z on 1997-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 17 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, Salt Lake City I, UT at 00:00Z on 1997-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 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
17 J/kg
Mixed-layer CIN
-131 J/kg
Mixed-layer LCL
2304 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
-6 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 220047 RRA
SVRSLC
IDC041-UTC003-005-220115-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
647 PM MDT WED MAY 21 1997

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY UT HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 715 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...

IN NORTHWESTERN UTAH

   ...NORTHEASTERN BOX ELDER COUNTY
   ...NORTHWESTERN CACHE COUNTY

IN SOUTHEASTERN IDAHO

   ...SOUTHWESTERN FRANKLIN COUNTY
 
AT 642 PM MDT...A LINE OF SEVERE THUNDERSTORMS WAS INDICATED BY
DOPPLER RADAR EXTENDING FROM WESTERN FRANKLIN COUNTY IN IDAHO
SOUTHWARD TO AROUND PLYMOUTH IN NORTHEASTERN BOX ELDER COUNTY IN
UTAH. THE LINE WAS MOVING EAST AT 30 MPH AND WILL AFFECT THE
FOLLOWING COMMUNITIES BY 715 PM.

TRENTON                AT AROUND 640 PM MDT
UTIDA                  AT AROUND 640 PM MDT
RIVERSIDE              AT AROUND 645 PM MDT
AMALGA                 AT AROUND 645 PM MDT
FAIRVIEW               AT AROUND 645 PM MDT
PRESTON                AT AROUND 645 PM MDT
LEWISTON               AT AROUND 650 PM MDT
SMITHFIELD             AT AROUND 650 PM MDT
WHITNEY                AT AROUND 650 PM MDT
RIVERDALE              A<T AROUND 650 PM MDT
FRANKLIN               AT AROUND 655 PM MDT
 
THESE STORMS MAY PRODUCE STRONG GUSTY WIND...LARGE HAIL...AND
FREQUENT LIGHTNING.  TAKE COVER WHEN THREATENING WEATHER APPROACHES.

The office that day

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

IssuedProductOfficeCountiesLasted
May 21, 6:47 PM MDTSevere Thunderstorm WarningSLCBox Elder28 min
May 22, 3:50 PM MDTSevere Thunderstorm WarningSLCKane45 min

Nearby

Severe Thunderstorm Warnings in Idaho, 1997Severe Thunderstorm Warnings in Utah, 1997Every severe thunderstorm warning in 1997

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.