Alert archive / Illinois / Severe Thunderstorm Warnings in 2001
Severe Thunderstorm Warning 64, NWS Chicago, IL
NWS Chicago, IL issued this severe thunderstorm warning at Aug 30, 2001, 1:46 PM CDT for Iroquois County, Illinois; Benton County, Indiana. It was in force for 44 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 30, 2001, 1:46 PM CDT (18:46 UTC)
- Expired
- Aug 30, 2001, 2:30 PM CDT
- In force
- 44 min
- Issued by
- NWS Chicago, IL
- Area
- Whole counties
Counties Iroquois County, IL, Benton County, IN
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 30, 1:46 PM CDT | Hail 1 | Boswell, IN |
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.
The nearest sounding before it
Davenport, (KDVN), launched 12:00Z, 6.8 hours before the alert went out and 267 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.
- Mixed-layer CAPE
- 394 J/kg
- Mixed-layer CIN
- -319 J/kg
- Mixed-layer LCL
- 1621 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- -1 m²/s²
- 0-3 km storm-relative helicity
- 29 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
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 Chicago, IL wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 30, 2:20 AM CDT, 11 hours 26 minutes earlier.
Area forecast discussion, Aug 30, 2:20 AM CDT, 11 hours 26 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 220 AM CDT THU AUG 30 2001 ANOTHER BEAUTI ON WED. TO END TODAY WITH FRONT IN AREA. AT 06Z VORT FCST ALL VERY SIMILIAR ON MODELS ALTHO AVN LOOKS THE BEST ON BOTH VORT PATTERN AND RH PATTERN. ALL SEEMS TO MISS THE MO VORT. ALL MODELS HAVE FALLING UPPER HEIGHTS THRU DAY AND HAVE SOME VORT PACKING AND DPVA INTO XTRM NW IL BY 18Z AND THEN TO NE IL BY 00Z. VORT CHANNEL FROM NE MI TO NE IL SE IA BY 12Z FRI ON ALL MODELS WITH THE TROF DROPPING SE FROM CANADA. AT 06Z BKN BAND TS FROM LS SW TO KS. ISO CELLS SE DSM AND VORT MAX AREA TS OVER NE 1/2 MO. AT 06Z LOOKS LIKE MN TS BREAKING OFF TO THE E. THIS MAKES SENSE BASED ON THE VORT FORECAST AT 700 AND HEIGHT CONFIGURATION OF ALL MODELS SHOWING A VORT TO MOVE QUICKLY THRU N WI TO NW MI BY 12Z THIS MORNING AND TRAILING VORT LOBE BACK TO NE CORNER OF SD WITH TRAILING BATCH OF TS. MN TS SHOULD SET UP GOOD SFC BOUNDARY OVER S WI E/W FROM AROUND MSN AREA. 700 VORT FORECASTS WOULD THEN IGNITE THIS AND PUSH INTO N IL/NW IN BY 00Z. NONE OF THE MODELS REAL CONSISTENT ON AMOUNT LOW LEVEL CONVERGENCE NOR UPPER LEVEL DIVERGENCE AND ALL SHOW BEST MID LEVEL INSTABILITY E OF AREA BY LATE AFTERNOON SO THE 40-60% POPS LOOK GOOD. LIKE QUICKER DRYING PATTERN OF RH ON ETA/NGM OVERNIGHT VS SLOWER AVN. SUN RETURN AGAIN FRIDAY WITH COOLER/LESS HUMID AIR. TEMP GUIDANCE LOOKS GOOD AND FOLLOWED. NICE PUSH OF COOLER AIR FOR THE HOLIDAY WEEKEND. .CHI...NONE AF
In the hours before
Special weather statement, Aug 30, 11:58 AM CDT, 1 hour 48 minutes before
ILZ003>006-008-010>014-019>023-032>033-039-INZ001>002-010>011-019- 311100- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHICAGO IL 1200 PM CDT/EST THU AUG 30 2001 FOR NORTH CENTRAL AND NORTHEAST ILLINOIS AND NORTHWEST INDIANA THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON AND THIS EVENING OVER THE ENTIRE AREA. A COLD FRONT EXTENDING FROM NORTHEAST WISCONSIN TO SOUTHWESTERN IOWA WILL BE PASSING THROUGH THE REGION TONIGHT. THE AIR IN ADVANCE OF THIS FRONT IS RATHER UNSTABLE AND SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP BY LATE AFTERNOON. A FEW OF THESE STORMS MAY PRODUCE GUSTY WINDS AND HAIL. MERZLOCK
The office that day
Everything else NWS Chicago, IL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 30, 1:20 PM CDT | Severe Thunderstorm Warning | LOT | Iroquois | 25 min |
Nearby
Severe Thunderstorm Warnings in Illinois, 2001Severe Thunderstorm Warnings in Indiana, 2001Every severe thunderstorm warning in 2001
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.