Alert archive / Indiana / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 31, NWS Indianapolis, IN

May 20, 1998Knox County, Indiana

NWS Indianapolis, IN issued this severe thunderstorm warning at May 20, 1998, 1:04 PM EST for Knox County, Indiana. It was in force for 46 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
May 20, 1998, 1:04 PM EST (18:04 UTC)
Expired
May 20, 1998, 1:50 PM EST
In force
46 min
Issued by
NWS Indianapolis, IN
Area
Whole counties

County Knox County, IN

What was reported inside it

TimeReportWhereRemark
May 20, 1:41 PM ESTThunderstorm WindMonroe City, INTrees downed.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 6.1 hours before the alert went out and 192 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, Lincoln, IL at 12:00Z on 1998-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 618 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, Lincoln, IL at 12:00Z on 1998-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 89 square meters per square second.193958Sfc1 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
618 J/kg
Mixed-layer CIN
-260 J/kg
Mixed-layer LCL
1294 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
89 m²/s²
0-3 km storm-relative helicity
142 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.

182 
WUUS1 KIND 201805 RRA
SVRIND
INC083-201850-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
104 PM EST WED MAY 20 1998

THE NATIONAL WEATHER SERVICE IN INDIANAPOLIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  KNOX COUNTY IN SOUTHWESTERN INDIANA

* UNTIL 150 PM EST

* AT 100 PM EST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 15 MILES WEST OF VINCENNES... MOVING EAST AT 25
  MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  VINCENNES BY 115 PM EST

DAMAGING WINDS AND LARGE HAIL ARE LIKELY. GO INSIDE A STURDY
BUILDING AND STAY AWAY FROM WINDOWS

TMA

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, May 20, 11:54 AM EST, 1 hour 10 minutes before
INZ021-028>031-035>049-051>057-060>065-067>072-202100-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1154 AM EST WED MAY 20 1998

...SEVERE STORMS POSSIBLE THIS AFTERNOON AND EVENING OVER CENTRAL
AND SOUTHERN INDIANA...

THE THREAT EXISTS FOR SEVERE THUNDERSTORMS ACROSS CENTRAL AND
SOUTHERN INDIANA THIS AFTERNOON AND EVENING. THE THREAT IS PRIMARILY
NEAR AND SOUTH OF A LAFAYETTE TO RICHMOND LINE. WESTERN INDIANAS
THREAT PERIOD WILL BEGIN BY MID AFTERNOON WHILE EASTERN INDIANA WILL
NOT LIKELY SEE ANY STORMS BEFORE EARLY EVENING. THE GREATEST
LIKELHOOD FOR SEVERE WEATHER IS ACROSS SOUTHWEST INDIANA.

THE MAIN THREATS WILL BE DAMAGING WINDS AND POTENTIAL FLOODING FROM
HEAVY RAINFALL. LARGE HAIL WILL ALSO BE POSSIBLE.

A FRONTAL BOUNDARY ACROSS CENTRAL PORTIONS OF ILLINOIS...INDIANA AND
OHIO WILL SERVE AS THE FOCUS FOR STORM DEVELOPMENT ONCE AN UPPER AIR
DISTURBANCE OVER IOWA THIS MORNING MOVES OVER SOUTHERN INDIANA BY
THIS EVENING.

SPOTTER ACTIVATION MAY BE NECESSARY THIS AFTERNOON AND EVENING.

TUCEK
Special weather statement, May 20, 11:54 AM EST, 1 hour 10 minutes before
INZ021-028>031-035>049-051>057-060>065-067>072-202100-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1154 AM EST WED MAY 20 1998

...SEVERE STORMS POSSIBLE THIS AFTERNOON AND EVENING OVER CENTRAL
AND SOUTHERN INDIANA...

THE THREAT EXISTS FOR SEVERE THUNDERSTORMS ACROSS CENTRAL AND
SOUTHERN INDIANA THIS AFTERNOON AND EVENING. THE THREAT IS PRIMARILY
NEAR AND SOUTH OF A LAFAYETTE TO RICHMOND LINE. WESTERN INDIANAS
THREAT PERIOD WILL BEGIN BY MID AFTERNOON WHILE EASTERN INDIANA WILL
NOT LIKELY SEE ANY STORMS BEFORE EARLY EVENING. THE GREATEST
LIKELHOOD FOR SEVERE WEATHER IS ACROSS SOUTHWEST INDIANA.

THE MAIN THREATS WILL BE DAMAGING WINDS AND POTENTIAL FLOODING FROM
HEAVY RAINFALL. LARGE HAIL WILL ALSO BE POSSIBLE.

A FRONTAL BOUNDARY ACROSS CENTRAL PORTIONS OF ILLINOIS...INDIANA AND
OHIO WILL SERVE AS THE FOCUS FOR STORM DEVELOPMENT ONCE AN UPPER AIR
DISTURBANCE OVER IOWA THIS MORNING MOVES OVER SOUTHERN INDIANA BY
THIS EVENING.

SPOTTER ACTIVATION MAY BE NECESSARY THIS AFTERNOON AND EVENING.

TUCEK

The office that day

Everything else NWS Indianapolis, IN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 19, 7:12 PM ESTFlash Flood WarningINDFountain, Vermillion, Warren3 hr
May 19, 7:12 PM ESTFlash Flood WarningINDParke3 hr
May 19, 7:45 PM ESTSevere Thunderstorm WarningINDClay45 min
May 19, 9:31 PM ESTSevere Thunderstorm WarningINDSullivan, Vigo34 min
May 19, 10:27 PM ESTSevere Thunderstorm WarningINDKnox33 min
May 20, 1:56 PM ESTSevere Thunderstorm WarningINDDaviess49 min

Nearby

Severe Thunderstorm Warnings in Indiana, 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.