Alert archive / Indiana / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 49, NWS Chicago, IL

June 12, 1998Porter County, Indiana

NWS Chicago, IL issued this severe thunderstorm warning at Jun 12, 1998, 3:43 PM CDT for Porter County, Indiana. It was in force for 32 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
Jun 12, 1998, 3:43 PM CDT (20:43 UTC)
Expired
Jun 12, 1998, 4:15 PM CDT
In force
32 min
Issued by
NWS Chicago, IL
Area
Whole counties

County Porter County, IN

The radar

The Chicago radar (KLOT), 85 km from the middle of the area, began a volume at 20:45 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jun 12, 2:45 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 8.7 hours before the alert went out and 198 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 1998-06-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 538 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 1998-06-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 105 square meters per square second.1939587897Sfc1 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
538 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
1016 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
105 m²/s²
0-3 km storm-relative helicity
129 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

269 
WUUS1 KCHI 122045 RRA
SVRCHI
INC127-122115-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHICAGO IL
343 PM CDT FRI JUN 12 1998

THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  PORTER COUNTY IN NORTHWEST INDIANA

* UNTIL 415 PM CDT

* AT 340 PM CDT A SEVERE THUNDERSTORM WAS INDICATED BY RADAR 5 MILES
  SOUTH OF VALPARAISO MOVING EAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE AFFECT...
  MALDEN

A TORNADO WATCH IS IN EFFECT FOR THIS AREA. REMEMBER...SEVERE
THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES.

$$

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, Jun 12, 10:42 AM CDT, 5 hours 1 minute before
ILZ003>006-008-010>014-019>023-032>033-039-INZ001>002-010>011-019-
131100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO IL
1100 AM CDT/EST FRI JUN 12 1998

FOR NORTH CENTRAL AND NORTHEAST ILLINOIS AND NORTHWEST INDIANA

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING SOUTH OF A CHICAGO...MARSEILLES LINE.

SLIGHTLY DRIER AIR PUSHED INTO NORTHERN ILLINOIS OVERNIGHT...BUT
THIS MORNING MOIST AIR IS SLOWLY RETURNING ON SOUTHWEST WINDS.
A WEAK FRONTAL SYSTEM ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE
OVER THE  UPPER MISSISSIPPI VALLEY WILL PUSH ACROSS THE AREA THIS
AFTERNOON AND EVENING SETTING  OFF SCATTERED THUNDERSTORMS. THE BEST
CHANCE FOR SEVERE THUNDERSTORMS WILL BE SOOUTH OF A CHICAGO...MARSEILLES
LINE WHERE THERE WILL BE MORE LOW LEVEL MOISTURE AVAILABLE.

KAHN

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.