Alert archive / Illinois / Severe Thunderstorm Warnings in 2001
Severe Thunderstorm Warning 67, NWS Chicago, IL
NWS Chicago, IL issued this severe thunderstorm warning at Sep 7, 2001, 7:45 PM CDT for Winnebago County, Illinois. It was in force for 30 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
- Sep 7, 2001, 7:45 PM CDT (00:45 UTC)
- Expired
- Sep 7, 2001, 8:15 PM CDT
- In force
- 30 min
- Issued by
- NWS Chicago, IL
- Area
- Whole counties
County Winnebago County, IL
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Sep 7, 8:05 PM CDT | Thunderstorm Wind 50 E | Rockton, IL | One tree blown down. |
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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Sep 7, 6:15 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Davenport, (KDVN), launched 00:00Z, 0.8 hours before the alert went out and 136 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
- 1494 J/kg
- Mixed-layer CIN
- -8 J/kg
- Mixed-layer LCL
- 1251 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 124 m²/s²
- 0-3 km storm-relative helicity
- 154 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 3.5
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 Sep 7, 3:15 PM CDT, 4 hours 30 minutes earlier.
Area forecast discussion, Sep 7, 3:15 PM CDT, 4 hours 30 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 315 PM CDT FRI SEP 7 2001 WELL...HAVE BACKED OFF ON POPS FOR CHI AREA BASED ON CURRENT SATLT TRENDS THAT SHOW NOTABLE LACK OF CU DVLPMT FROM CHI SWWD ACROSS WRN IL/E CNTRL MO. MSAS GRAPHICS HAVE DONE WELL DEPICTING MINIMUM OF MOISTURE CONVERGENCE IN THE RGN AS WELL. MOST RECENT RUC CONTINUES THIS TREND THRU THIS EVE SO WILL JUST GO WITH CHC POPS FOR A LARGE PART OF THE FA. WILL KEEP MENTION IN SINCE AMD IS RATHER UNSTABLE WITH TEMPS IN UPPER 80S AND DWPTS IN UPR 60S-LWR 70S. ALSO 88-D RADAR SHOWS NWWD MOVG OUTFLO BOUNDARY FROM NR PONTIAC TO GARY. A FEW SMALL CELLS DVLPD ON THIS BOUNDARY OVER LAKE CO IN A LTL EARLIER AND ADDITIONAL DVLPMT WILL REMAIN PSBL THRU THE EVENING HRS. WILL GO WITH UNQUALIFIED MENTION OF TSTMS OVER SERN COUNTIES WHERE TSTMS ARE ONGOING. AM EXPECTING THIS ACTIVITY TO DIMINISH AS THE EVENING WEARS ON SINCE IT IS MAINLY DUIRNALLY DRIVEN. WILL ALSO GO WITH HIER POPS /LIKELY CAT/ OVER N CNTRL IL IN RFD VCNTY. CLUSTER OF STG/SVR TSTMS OVER CNTRL IA ATTM WILL CONT NEWD AND SHOULD CLIP NWRN COUNTIES LATER THIS EVE. ON SAT...ETA AND AVN NOW IN BETTER AGREEMENT ON TIMING OF VORT MAX AND COLD FROPA. VORT LOBE FCST TO PASS THRU AREA ARND 18Z SAT AND THIS SHOULD CONCENTRATE SHWRS/TSTMS DURING MRNG HRS AND LIMIT DVLPMT IN AFTN. SFC WAVE GOES BY ERLY SAT EVE FOLLOWED BY TEMPORARY DRYING AND NWLY-NLY SFC FLO. ON SUN...CLOUDINESS EXPCTED TO INCRS AGAIN AS BOTH ETA AND AVN SWING SIG S/W AROUND BASE OF H5 TROF. SFC WAVE FCST TO DVLP ALG FRONT SUN NGT-MON WITH UPR LO PASSING S OF FA ON MON. /OH...IF ONLY THIS WERE DEC.../ ANYWAY...AM SOMEWHAT SKEPTICAL OF THIS SCENARIO DUE TO TIME OF YR BUT WILL HAVE PRECIP IN FOR SUN NGT-MON. .CHI...NONE MERZLOCK
Nearby
Severe Thunderstorm Warnings in Illinois, 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.