Alert archive / Idaho / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 2, NWS Boise, ID

April 30, 1997Elmore County, Idaho

NWS Boise, ID issued this severe thunderstorm warning at Apr 30, 1997, 4:57 PM MDT for Elmore County, Idaho. It was in force for 48 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
Apr 30, 1997, 4:57 PM MDT (22:57 UTC)
Expired
Apr 30, 1997, 5:45 PM MDT
In force
48 min
Issued by
NWS Boise, ID
Area
Whole counties

County Elmore County, ID

The radar

The Boise radar (KCBX), 64 km from the middle of the area, began a volume at 22:56 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

Boise Airport, ID (KBOI), launched 12:00Z, 11.0 hours before the alert went out and 64 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, Boise Airport, ID at 12:00Z on 1997-04-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 31 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, Boise Airport, ID at 12:00Z on 1997-04-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 40 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
31 J/kg
Mixed-layer CIN
-38 J/kg
Mixed-layer LCL
1407 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
40 m²/s²
0-3 km storm-relative helicity
166 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 KBOI 302259 RRA
SVRBOI
IDC039-302345-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BOISE ID
457 PM MDT WED APR 30 1997
 
THE NATIONAL WEATHER SERVICE IN BOISE ID HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  545 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHWEST IDAHO
 
   ...NORTHWESTERN ELMORE COUNTY
 
AT 500 PM MDT BOISE WEATHER RADAR HAS INDICATED A SEVERE THUNDERSTORM 10
MILES WEST OF PRAIRIE OR 25 MILES EAST OF BOISE.
 
THE STORM IS MOVING SOUTHEAST AT ABOUT 25 MILES AN HOUR AND WILL AFFECT
THE COMMUNITY OF PRAIRIE BY 515 PM. THE STORM WILL APPROACH THE ANDERSON
RANCH DAM ABOUT 530 PM.
 
IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER 
FROM THE WEATHER IN A
STRONG BUILDING.  DAMAGING WIND...LARGE HAIL...VERY HEAVY RAIN...
AND DEADLY LIGHTNING ARE ALL POSSIBLE IN SEVERE THUNDERSTORMS.
STAY INSIDE AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.

The office that day

Everything else NWS Boise, ID issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 30, 3:20 PM MDTSevere Thunderstorm WarningBOIWashington55 min
Apr 30, 3:27 PM MDTTornado WarningBOIPayette, Washington63 min

Nearby

Severe Thunderstorm Warnings in Idaho, 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; radar from the NEXRAD Level II archive.