Alert archive / Illinois / Tornado Watches in 1999

Tornado Watch 138

April 8, 199957 counties in Illinois; City of Saint Louis, Missouri

The Storm Prediction Center issued this tornado watch at Apr 8, 1999, 8:00 PM CDT for 57 counties in Illinois; City of Saint Louis, Missouri. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 8, 1999, 8:00 PM CDT (01:00 UTC)
Expired
Apr 9, 1999, 1:00 AM CDT
In force
5 hr
Issued by
the Storm Prediction Center
All 58 counties

Bond County, IL, Bureau County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Ford County, IL, Fulton County, IL, Grundy County, IL, Henry County, IL, Iroquois County, IL, Jasper County, IL, Jefferson County, IL, Jersey County, IL, Kankakee County, IL, Kendall County, IL, Knox County, IL, LaSalle County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Marshall County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Putnam County, IL, Richland County, IL, Saint Clair County, IL, Sangamon County, IL, Shelby County, IL, Stark County, IL, Tazewell County, IL, Vermilion County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, Will County, IL, Woodford County, IL, City of Saint Louis, MO

The radar

The Lincoln radar (KILX), 58 km from the middle of the area, began a volume at 01:02 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.

Warnings issued inside it

30 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Apr 8, 8:16 PM CDTTornado WarningILXMorgan, Scott44 min
Apr 8, 8:20 PM CDTTornado WarningDVNHenry40 min
Apr 8, 8:32 PM CDTTornado WarningILXFulton, Knox28 min
Apr 8, 8:42 PM CDTSevere Thunderstorm WarningILXPeoria, Stark48 min
Apr 8, 8:56 PM CDTSevere Thunderstorm WarningILXSangamon64 min
Apr 8, 9:17 PM CDTSevere Thunderstorm WarningILXMarshall, Woodford58 min
Apr 8, 9:17 PM CDTTornado WarningILXMenard28 min
Apr 8, 9:29 PM CDTSevere Thunderstorm WarningILXPeoria31 min
Apr 8, 9:38 PM CDTSevere Thunderstorm WarningILXTazewell37 min
Apr 8, 9:41 PM CDTSevere Thunderstorm WarningILXLogan34 min
Apr 8, 9:47 PM CDTSevere Thunderstorm WarningILXChristian, Macon58 min
Apr 8, 10:02 PM CDTTornado WarningILXChristian28 min
Apr 8, 10:13 PM CDTTornado WarningILXMacon32 min
Apr 8, 10:17 PM CDTSevere Thunderstorm WarningLSXBond, Montgomery43 min
Apr 8, 10:20 PM CDTSevere Thunderstorm WarningLSXFayette50 min
Apr 8, 10:28 PM CDTSevere Thunderstorm WarningILXShelby47 min
Apr 8, 10:32 PM CDTSevere Thunderstorm WarningILXMoultrie, Piatt28 min
Apr 8, 10:37 PM CDTTornado WarningILXPiatt23 min
Apr 8, 10:47 PM CDTTornado WarningILXChampaign28 min
Apr 8, 10:54 PM CDTTornado WarningILXEffingham36 min
Apr 8, 10:56 PM CDTSevere Thunderstorm WarningILXColes, Douglas34 min
Apr 8, 11:13 PM CDTTornado WarningILXCumberland32 min
Apr 8, 11:15 PM CDTTornado WarningILXShelby15 min
Apr 8, 11:17 PM CDTTornado WarningILXChampaign, Vermilion28 min
Apr 8, 11:20 PM CDTSevere Thunderstorm WarningILXVermilion25 min
Apr 8, 11:30 PM CDTTornado WarningILXColes, Edgar30 min
Apr 8, 11:33 PM CDTSevere Thunderstorm WarningILXClay, Effingham, Jasper42 min
Apr 8, 11:45 PM CDTTornado WarningILXClark, Cumberland30 min
Apr 8, 11:48 PM CDTSevere Thunderstorm WarningILXVermilion27 min
Apr 8, 11:52 PM CDTTornado WarningILXEdgar38 min

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 1.0 hours before the alert went out and 82 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 00:00Z on 1999-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 859 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 00:00Z on 1999-04-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 344 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
859 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
1075 m above ground
0-6 km bulk shear
73 kt
0-1 km storm-relative helicity
344 m²/s²
0-3 km storm-relative helicity
449 m²/s²
Significant tornado parameter
1.9
Supercell composite
8.7

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

Nearby

Tornado Watches in Illinois, 1999Tornado Watches in Missouri, 1999Every tornado watch 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.