Alert archive / Illinois / Tornado Warnings in 1999
Tornado Warning 21, NWS Quad Cities, IA
NWS Quad Cities, IA issued this tornado warning at May 17, 1999, 12:00 AM CDT for Carroll County, Whiteside County, Illinois. It was in force for 30 min. 2 reports 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
- May 17, 1999, 12:00 AM CDT (05:00 UTC)
- Expired
- May 17, 1999, 12:30 AM CDT
- In force
- 30 min
- Issued by
- NWS Quad Cities, IA
- Area
- Whole counties
Counties Carroll County, IL, Whiteside County, IL
The radar
The Quad Cities radar (KDVN), 64 km from the middle of the area, began a volume at 04:59 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| May 17, 12:10 AM CDT | Thunderstorm Wind | Fulton, IL | Trees were downed by severe thunderstorm winds. |
| May 17, 12:15 AM CDT | Thunderstorm Wind | Shannon, IL | Severe thunderstorm winds first blew apart a hog shed, which caused power lines to fall onto a barn. The barn and about 400 head of hog were lost in the resulting fire. |
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 |
|---|---|---|---|
| May 16, 11:00 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Davenport, (KDVN), launched 00:00Z, 5.0 hours before the alert went out and 58 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
- 3009 J/kg
- Mixed-layer CIN
- -2 J/kg
- Mixed-layer LCL
- 1174 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 61 m²/s²
- 0-3 km storm-relative helicity
- 102 m²/s²
- Significant tornado parameter
- 0.7
- Supercell composite
- 5.9
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KMLI 170500 RRA TORMLI ILC015-195-170530- BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE QUAD CITIES IA IL 1200 AM CDT MON MAY 17 1999 THE NATIONAL WEATHER SERVICE IN QUAD CITIES IA HAS ISSUED A * TORNADO WARNING FOR... CARROLL COUNTY IN NORTHWESTERN ILLINOIS WHITESIDE COUNTY IN NORTHWESTERN ILLINOIS * UNTIL 1230 AM CDT * AT 1157 PM CDT... DOPPLER RADAR INDICATED A DEVELOPING TORNADO 14 MILES NORTHEAST OF CLINTON OR 5 MILES SOUTHWEST OF MT CARROLL MOVING EAST AT 40 MPH. * THE TORNADO IS EXPECTED TO BE NEAR... MT CARROLL AROUND MIDNIGHT CDT CHADWICK AROUND 1205 AM CDT LANARK AROUND 1210 AM CDT SHANNON AROUND 1220 AM CDT SPOTTERS AND THE PUBLIC HAVE REPORTED SEVERAL FUNNEL CLOUDS WITH THE LINE OF STORMS MOVING INTO CARROLL AND WHITESIDE COUNTIES. GO TO THE BASEMENT OR A SMALL INTERIOR ROOM ON THE LOWEST FLOOR! MCCLURE
The office that day
Everything else NWS Quad Cities, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 16, 8:51 PM CDT | Severe Thunderstorm Warning | DVN | Jo Daviess | 49 min |
| May 16, 9:10 PM CDT | Tornado Warning | DVN | Jo Daviess | 35 min |
| May 16, 11:28 PM CDT | Severe Thunderstorm Warning | DVN | Rock Island | 47 min |
| May 16, 11:36 PM CDT | Flash Flood Warning | DVN | Jo Daviess | 6 hr |
| May 16, 11:37 PM CDT | Severe Thunderstorm Warning | DVN | Carroll, Jo Daviess | 48 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.