Alert archive / Illinois / Tornado Watches in 1997

Tornado Watch 297

May 18, 199744 counties in Illinois; Clinton County, Scott County, Iowa

The Storm Prediction Center issued this tornado watch at May 18, 1997, 5:30 PM CDT for 44 counties in Illinois; Clinton County, Scott County, Iowa. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 18, 1997, 5:30 PM CDT (22:30 UTC)
Expired
May 18, 1997, 11:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 46 counties

Clinton County, IA, Scott County, IA, Boone County, IL, Bureau County, IL, Carroll County, IL, Cook County, IL, DeKalb County, IL, DeWitt County, IL, DuPage County, IL, Ford County, IL, Fulton County, IL, Grundy County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Knox County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Logan County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McHenry County, IL, McLean County, IL, Menard County, IL, Mercer County, IL, Ogle County, IL, Peoria County, IL, Piatt County, IL, Putnam County, IL, Rock Island County, IL, Schuyler County, IL, Stark County, IL, Stephenson County, IL, Tazewell County, IL, Warren County, IL, Whiteside County, IL, Will County, IL, Winnebago County, IL, Woodford County, IL

The radar

The Quad Cities radar (KDVN), 92 km from the middle of the area, began a volume at 22:33 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

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

IssuedProductOfficeCountiesLasted
May 18, 5:40 PM CDTSevere Thunderstorm WarningDVNCarroll, Whiteside50 min
May 18, 5:49 PM CDTSevere Thunderstorm WarningDVNClinton46 min
May 18, 5:51 PM CDTSevere Thunderstorm WarningLOTOgle69 min
May 18, 6:30 PM CDTSevere Thunderstorm WarningLOTBoone45 min
May 18, 6:41 PM CDTSevere Thunderstorm WarningLOTLee64 min
May 18, 6:45 PM CDTTornado WarningLOTLee60 min
May 18, 6:56 PM CDTSevere Thunderstorm WarningLOTLake, McHenry64 min
May 18, 7:00 PM CDTTornado WarningLOTLake, McHenry60 min
May 18, 7:09 PM CDTSevere Thunderstorm WarningLOTKane66 min
May 18, 7:10 PM CDTSevere Thunderstorm WarningDVNBureau50 min
May 18, 7:19 PM CDTSevere Thunderstorm WarningLOTLaSalle, Lee56 min
May 18, 7:24 PM CDTSevere Thunderstorm WarningDVNClinton51 min
May 18, 7:30 PM CDTTornado WarningLOTKane30 min
May 18, 7:31 PM CDTSevere Thunderstorm WarningDVNScott49 min
May 18, 7:42 PM CDTSevere Thunderstorm WarningLOTKendall, LaSalle63 min
May 18, 7:47 PM CDTTornado WarningLOTDuPage, Will58 min
May 18, 7:52 PM CDTTornado WarningDVNScott48 min
May 18, 8:01 PM CDTTornado WarningDVNRock Island49 min
May 18, 8:03 PM CDTSevere Thunderstorm WarningDVNHenderson52 min
May 18, 8:04 PM CDTTornado WarningLOTGrundy, Kankakee, Will56 min
May 18, 8:04 PM CDTTornado WarningLOTCook56 min
May 18, 8:13 PM CDTTornado WarningDVNHenry47 min
May 18, 8:26 PM CDTSevere Thunderstorm WarningDVNWarren49 min
May 18, 8:33 PM CDTSevere Thunderstorm WarningILXKnox47 min
May 18, 8:38 PM CDTSevere Thunderstorm WarningDVNBureau47 min
May 18, 8:46 PM CDTTornado WarningDVNBureau49 min
May 18, 8:50 PM CDTSevere Thunderstorm WarningDVNHenderson45 min
May 18, 8:52 PM CDTSevere Thunderstorm WarningLOTFord, Iroquois, Kankakee2 hr
May 18, 8:52 PM CDTSevere Thunderstorm WarningLOTLivingston2 hr
May 18, 8:59 PM CDTSevere Thunderstorm WarningDVNMercer36 min
May 18, 9:07 PM CDTTornado WarningDVNWarren48 min
May 18, 9:14 PM CDTTornado WarningDVNPutnam31 min
May 18, 9:17 PM CDTTornado WarningILXKnox48 min
May 18, 9:18 PM CDTTornado WarningLOTLaSalle57 min
May 18, 9:31 PM CDTTornado WarningILXFulton, Peoria49 min
May 18, 9:54 PM CDTSevere Thunderstorm WarningLOTGrundy, Livingston66 min
May 18, 10:10 PM CDTTornado WarningILXTazewell50 min
May 18, 10:13 PM CDTTornado WarningILXPeoria32 min
May 18, 10:17 PM CDTSevere Thunderstorm WarningILXKnox43 min
May 18, 10:50 PM CDTSevere Thunderstorm WarningLOTIroquois, Kankakee55 min

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 10.5 hours before the alert went out and 88 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 1997-05-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 1997-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 266 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1986 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
266 m²/s²
0-3 km storm-relative helicity
293 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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.

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 18, 2:30 PM CDTTornado WatchSPCHenderson, Jo Daviess, Mercer, Rock Island7 hr

Nearby

Tornado Watches in Illinois, 1997Tornado Watches in Iowa, 1997Every tornado watch in 1997

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.