Alert archive / Illinois / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 9, NWS Lincoln, IL

February 11, 1999Cass County, Illinois

NWS Lincoln, IL issued this severe thunderstorm warning at Feb 11, 1999, 2:40 PM CST for Cass County, Illinois. It was in force for 35 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: Feb 11, 1999, 2:40 PM CST (20:40 UTC)
Expired: Feb 11, 1999, 3:15 PM CST
In force: 35 min
Issued by: NWS Lincoln, IL
Area: Whole counties

County Cass County, IL

The radar

The Lincoln radar (KILX), 80 km from the middle of the area, began a volume at 20:42 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.

Issued	Product	Office	Lasted
Feb 11, 11:15 AM CST	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 8.7 hours before the alert went out and 142 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: 394 J/kg
Mixed-layer CIN: -231 J/kg
Mixed-layer LCL: 746 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 293 m²/s²
0-3 km storm-relative helicity: 310 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KSPI 112041
SVRSPI
ILC017-112115-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LINCOLN IL
240 PM CST THU FEB 11 1999

THE NATIONAL WEATHER SERVICE IN LINCOLN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CASS COUNTY IN CENTRAL ILLINOIS

* UNTIL 315 PM CST

* AT 235 PM CST... DOPPLER RADAR INDICATED A LINE OF SEVERE
  THUNDERSTORMS EXTENDING FROM 10 MILES NORTHWEST OF JACKSONVILLE TO
  BEARDSTOWN... MOVING NORTHEAST AT 50 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  BEARDSTOWN
  BLUFF SPRINGS
  VIRGINIA
  CHANDLERVILLE

DAMAGING WIND GUSTS OF 60 MPH OR HIGHER CAN BE EXPECTED. GET INSIDE
A STURDY BUILDING AND STAY AWAY FROM WINDOWS.

AUTEN/KETCHAM/PLAHMER

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.

NWS Lincoln, IL wrote its last area forecast discussion before this severe thunderstorm warning went out at Feb 11, 2:00 PM CST, 40 minutes earlier.

Area forecast discussion, Feb 11, 2:00 PM CST, 40 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
200 PM CST THU FEB 11 1999

NGM A BIT SLOWER ON THE FNTL MOVMT THAN THE ETA AND AVN. MAPS DATA ON
AWIPS SHOWS FNT IS MOVG A BIT FASTER THAN EVEN THE FASTEST MODEL.
SQUALL LINE HAS DVLPD AND MOVING INTO CWA NOW. EXPECT THE BEST
POTENTIAL IS FOR DAMAGING WINDS AND SOME HAIL...AS THE DIRECTIONAL
SHEAR IS NOT THAT STRONG. SOME POSSIBLE SPIN UP TORNADOES...BUT
DAMAGING WINDS THE BEST THREAT DU|E TO THE VERY STRONG WINDS ALOFT.

PIA  25/27  +3
SPI  27/29  +3
DEC  27/29  +3
CMI  30/31  +3
LWV  32/34  +5

GOETSCH

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 11, 12:47 PM CST	Severe Thunderstorm Warning	ILX	Schuyler	43 min
Feb 11, 1:27 PM CST	Severe Thunderstorm Warning	ILX	Fulton, Knox	33 min
Feb 11, 2:00 PM CST	Severe Thunderstorm Warning	ILX	Peoria, Stark	45 min
Feb 11, 2:17 PM CST	Tornado Warning	ILX	Scott	28 min
Feb 11, 2:26 PM CST	Tornado Warning	ILX	Morgan	34 min
Feb 11, 3:34 PM CST	Tornado Warning	ILX	Tazewell	26 min
Feb 11, 3:53 PM CST	Tornado Warning	ILX	Woodford	37 min
Feb 11, 4:51 PM CST	Severe Thunderstorm Warning	ILX	Champaign	39 min
Feb 11, 5:17 PM CST	Severe Thunderstorm Warning	ILX	Clay	28 min
Feb 11, 5:27 PM CST	Severe Thunderstorm Warning	ILX	Clark, Edgar	33 min

Nearby

Severe Thunderstorm Warnings in Illinois, 1999 Every severe thunderstorm warning in 1999

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.