Alert archive / Iowa / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 111, NWS Quad Cities, IA
NWS Quad Cities, IA issued this severe thunderstorm warning at Jul 28, 1999, 4:50 AM CDT for Lee County, Iowa; Hancock County, Illinois. It was in force for 50 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
- Jul 28, 1999, 4:50 AM CDT (09:50 UTC)
- Expired
- Jul 28, 1999, 5:40 AM CDT
- In force
- 50 min
- Issued by
- NWS Quad Cities, IA
- Area
- Whole counties
Counties Lee County, IA, Hancock County, IL
The radar
The Quad Cities radar (KDVN), 136 km from the middle of the area, began a volume at 09:52 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 |
|---|---|---|---|
| Jul 28, 5:00 AM CDT | Thunderstorm Wind 51 | Ft Madison, IA | A line of thunderstorms produced 60 mph winds, which downed tree limbs in Ft. Madison. |
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 00:00Z, 9.8 hours before the alert went out and 140 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
- 2133 J/kg
- Mixed-layer CIN
- -8 J/kg
- Mixed-layer LCL
- 1051 m above ground
- 0-6 km bulk shear
- 50 kt
- 0-1 km storm-relative helicity
- 80 m²/s²
- 0-3 km storm-relative helicity
- 164 m²/s²
- Significant tornado parameter
- 2.0
- Supercell composite
- 12.4
The text
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
The office that day
Everything else NWS Quad Cities, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 27, 11:22 PM CDT | Severe Thunderstorm Warning | DVN | Louisa, Muscatine | 48 min |
| Jul 27, 11:55 PM CDT | Severe Thunderstorm Warning | DVN | Scott | 45 min |
| Jul 27, 11:55 PM CDT | Severe Thunderstorm Warning | DVN | Mercer, Rock Island | 45 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 1999Severe Thunderstorm Warnings in Illinois, 1999Every severe thunderstorm warning 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.