Alert archive / Illinois / Tornado Warnings in 1999

Tornado Warning 13, NWS Quad Cities, IA

May 12, 1999Carroll County, Illinois

NWS Quad Cities, IA issued this tornado warning at May 12, 1999, 4:47 PM CDT for Carroll County, Illinois. It was in force for 33 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
May 12, 1999, 4:47 PM CDT (21:47 UTC)
Expired
May 12, 1999, 5:20 PM CDT
In force
33 min
Issued by
NWS Quad Cities, IA
Area
Whole counties

County Carroll County, IL

The radar

The Quad Cities radar (KDVN), 74 km from the middle of the area, began a volume at 21:50 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

Davenport, (KDVN), launched 12:00Z, 9.8 hours before the alert went out and 68 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, Davenport, at 12:00Z on 1999-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 18 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, Davenport, at 12:00Z on 1999-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -37 square meters per square second.1939Sfc1 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
18 J/kg
Mixed-layer CIN
-131 J/kg
Mixed-layer LCL
1236 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
-37 m²/s²
0-3 km storm-relative helicity
-29 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.

999 
WFUS1 KMLI 122149 RRA
TORMLI
ILC015-122220-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
447 PM CDT WED MAY 12 1999

THE NATIONAL WEATHER SERVICE IN QUAD CITIES IA HAS ISSUED A

* TORNADO WARNING FOR...
  CARROLL COUNTY IN NORTHWESTERN ILLINOIS

* UNTIL 520 PM CDT

* AT 445 PM CDT... AREA LAW ENFORCEMENT INDICATED A FUNNEL CLOUD 4
  MILES SOUTH OF MT CARROLL... MOVING NORTH AT 10 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  MT CARROLL AT 455 PM

ABANDON MOBILE HOMES GO IN A NEARBY STURDY BUILDING. AS A LAST
RESORT LIE FLAT IN A DITCH AND COVER YOUR HEAD.

WOLF

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 12, 3:54 PM CDTSevere Thunderstorm WarningDVNCarroll31 min
May 12, 4:01 PM CDTTornado WarningDVNCarroll29 min
May 12, 5:25 PM CDTTornado WarningDVNWhiteside35 min
May 12, 5:52 PM CDTTornado WarningDVNHenry33 min
May 12, 6:06 PM CDTSevere Thunderstorm WarningDVNWhiteside34 min
May 12, 6:27 PM CDTTornado WarningDVNWhiteside33 min

Nearby

Tornado Warnings in Illinois, 1999Every tornado warning in 1999Tornadoes 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.