Alert archive / Illinois / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 70, NWS Lincoln, IL

August 28, 1990DeKalb County, Illinois

NWS Lincoln, IL issued this severe thunderstorm warning at Aug 28, 1990, 2:29 PM CDT for DeKalb County, Illinois. It was in force for 31 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: Aug 28, 1990, 2:29 PM CDT (19:29 UTC)
Expired: Aug 28, 1990, 3:00 PM CDT
In force: 31 min
Issued by: NWS Lincoln, IL
Area: Whole counties

County DeKalb County, IL

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

What was reported inside it

Time	Report	Where	Remark
Aug 28, 2:55 PM CDT	Thunderstorm Wind 80	De Kalb, IL

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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 7.5 hours before the alert went out and 293 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2944 J/kg
Mixed-layer CIN: -18 J/kg
Mixed-layer LCL: 575 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 75 m²/s²
0-3 km storm-relative helicity: 83 m²/s²
Significant tornado parameter: 1.1
Supercell composite: 4.9

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KRFD 281929
SVRRFD
ILC037-282000-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING 
NATIONAL WEATHER SERVICE ROCKFORD IL
229 PM CDT TUE AUG 28 1990

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 300 PM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTY

   IN THE NORTH CENTRAL PART OF ILLINOIS
      NORTHERN DEKALB

THIS AFTERNOON AT 230 CDT A SEVERE THUNDERSTORM WAS LOCATED IN
NORTHWEST DEKALB COUNTY NEAR KIRKLAND...ABOUT 20 MILES SOUTHEAST
OF ROCKFORD ILLINOIS. IT WAS MOVING EAST SOUTHEAST AT 25 MPH
AND WAS PRODUCING HAIL IN EXCESS OF ONE INCH IN DIAMETER.

SOME COMMUNITIES THAT WILL BE AFFECTED BY THIS SEVERE THUNDERSTORM...
GENOA...AND DEKALB.

IF YOU ARE IN AN AREA THREATENED BY THE STORM... GO TO A REINFORECED
SHELTER.  SEVERE THUNDERSTORMS CAN PRODUCE WINDS OF 60 MPH OR
GREATER... LARGE HAIL... DANGEROUS LIGHTNING AND HEAVY RAIN THAT
CAN QUICKLY FLOOD A LOW LYING AREA.

REMEMBER.V.. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
A TORNADO WITH LITTLE OR NO ADVANCE WARNING SO BE ALERT!

ATTN: ISP DIST  1..2..16                                FIELDS

The office that day

Everything else NWS Lincoln, IL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 28, 1:39 PM CDT	Tornado Warning	ILX	Boone, DeKalb, Winnebago	51 min
Aug 28, 1:57 PM CDT	Tornado Warning	ILX	Ogle	33 min
Aug 28, 2:58 PM CDT	Severe Thunderstorm Warning	ILX	DeKalb	32 min

Nearby

Severe Thunderstorm Warnings in Illinois, 1990 Every severe thunderstorm warning in 1990

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.