Alert archive / Illinois / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 111, NWS St. Louis, MO
NWS St. Louis, MO issued this severe thunderstorm warning at May 20, 1998, 9:18 AM CDT for Brown County, Illinois. It was in force for 47 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- May 20, 1998, 9:18 AM CDT (14:18 UTC)
- Expired
- May 20, 1998, 10:05 AM CDT
- In force
- 47 min
- Issued by
- NWS St. Louis, MO
- Area
- Whole counties
County Brown County, IL
The radar
The Lincoln radar (KILX), 122 km from the middle of the area, began a volume at 14:17 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.
The nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 2.3 hours before the alert went out and 184 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
- 618 J/kg
- Mixed-layer CIN
- -260 J/kg
- Mixed-layer LCL
- 1294 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 89 m²/s²
- 0-3 km storm-relative helicity
- 142 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.
In the hours before
Special weather statement, May 20, 6:00 AM CDT, 3 hours 18 minutes before
ILZ058>060-064-065-069-070-074-079-095>102-MOZ009-010-018-019-026- 027-034>036-041-042-047>052-059>065-072>075-084-085-099-201700- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE ST LOUIS MO 600 AM CDT WED MAY 20 1998 THIS OUTLOOK COVERS THE COUNTY WARNING AREA OF THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN ST LOUIS. AREAS INCLUDED ARE PORTIONS OF NORTHEAST...CENTRAL...EAST CENTRAL AND SOUTHEAST MISSOURI AS WELL AS WEST CENTRAL AND SOUTHWEST ILLINOIS. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER CENTRAL... EAST CENTRAL AND NORTHEAST MISSOURI AND ADJACENT SECTIONS OF WEST CENTRAL ILLINOIS. A LINE OF STRONG THUNDERSTORMS OVER NORTHWEST MISSOURI IS EXPECTED TO CONTINUE EAST THIS MORNING BRINGING A THREAT OF SEVERE THUNDER- STORMS TO NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS BY MID-MORNING. FURTHER SOUTH THE RISK OF SEVERE WEATHER WILL BE MAINLY DURING THE AFTERNOON AND EVENING HOURS. A WEAK COLD FRONT ACROSS NORTHERN MISSOURI IS FORECAST TO DROP SOUTH TO NEAR THE MISSOURI RIVER BY THIS EVENING. THIS FRONT WILL HELP SET OFF THUNDERSTORMS ACROSS CENTRAL AND EAST CENTRAL MISSOURI. STORM SPOTTER GROUPS AND EMERGENCY MANAGERS SHOULD MONITOR ADDITIONAL WEATHER DEVELOPMENTS FOR POSSIBLE SKYWARN ACTIVATION. FERRY
Special weather statement, May 20, 6:00 AM CDT, 3 hours 18 minutes before
ILZ058>060-064-065-069-070-074-079-095>102-MOZ009-010-018-019-026- 027-034>036-041-042-047>052-059>065-072>075-084-085-099-201700- SEVERE WEATHER OUTLOOK NATIONAL WEATHER SERVICE ST LOUIS MO 600 AM CDT WED MAY 20 1998 THIS OUTLOOK COVERS THE COUNTY WARNING AREA OF THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN ST LOUIS. AREAS INCLUDED ARE PORTIONS OF NORTHEAST...CENTRAL...EAST CENTRAL AND SOUTHEAST MISSOURI AS WELL AS WEST CENTRAL AND SOUTHWEST ILLINOIS. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER CENTRAL... EAST CENTRAL AND NORTHEAST MISSOURI AND ADJACENT SECTIONS OF WEST CENTRAL ILLINOIS. A LINE OF STRONG THUNDERSTORMS OVER NORTHWEST MISSOURI IS EXPECTED TO CONTINUE EAST THIS MORNING BRINGING A THREAT OF SEVERE THUNDER- STORMS TO NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS BY MID-MORNING. FURTHER SOUTH THE RISK OF SEVERE WEATHER WILL BE MAINLY DURING THE AFTERNOON AND EVENING HOURS. A WEAK COLD FRONT ACROSS NORTHERN MISSOURI IS FORECAST TO DROP SOUTH TO NEAR THE MISSOURI RIVER BY THIS EVENING. THIS FRONT WILL HELP SET OFF THUNDERSTORMS ACROSS CENTRAL AND EAST CENTRAL MISSOURI. STORM SPOTTER GROUPS AND EMERGENCY MANAGERS SHOULD MONITOR ADDITIONAL WEATHER DEVELOPMENTS FOR POSSIBLE SKYWARN ACTIVATION. FERRY
The office that day
Everything else NWS St. Louis, MO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 20, 8:52 AM CDT | Severe Thunderstorm Warning | LSX | Adams | 33 min |
| May 20, 9:21 AM CDT | Severe Thunderstorm Warning | LSX | Macoupin | 64 min |
| May 20, 9:24 AM CDT | Severe Thunderstorm Warning | LSX | Brown | 41 min |
Nearby
Severe Thunderstorm Warnings in Illinois, 1998Every severe thunderstorm warning in 1998
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.