Alert archive / Iowa / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 1, NWS Quad Cities, IA
NWS Quad Cities, IA issued this severe thunderstorm warning at Feb 11, 1999, 12:06 PM CST for Dubuque County, Jackson County, Iowa. It was in force for 34 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
- Feb 11, 1999, 12:06 PM CST (18:06 UTC)
- Expired
- Feb 11, 1999, 12:40 PM CST
- In force
- 34 min
- Issued by
- NWS Quad Cities, IA
- Area
- Whole counties
Counties Dubuque County, IA, Jackson County, IA
The radar
The Quad Cities radar (KDVN), 80 km from the middle of the area, began a volume at 18:06 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 |
|---|---|---|---|
| Feb 11, 12:16 PM CST | Hail 0.8 | Dubuque, IA | |
| Feb 11, 12:50 PM CST | Thunderstorm Wind | Central Portion, IA |
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, 6.1 hours before the alert went out and 80 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
- 263 J/kg
- Mixed-layer CIN
- -346 J/kg
- Mixed-layer LCL
- 653 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 395 m²/s²
- 0-3 km storm-relative helicity
- 310 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 Quad Cities, IA wrote its last area forecast discussion before this severe thunderstorm warning went out at Feb 11, 10:09 AM CST, 1 hour 57 minutes earlier.
Area forecast discussion, Feb 11, 10:09 AM CST, 1 hour 57 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 1009 AM CST THU FEB 11 1999 COLD FRONT MAKING GOOD PROGRESS ACROSS EASTERN IOWA WITH A WAVE RIDING UP THE FRONT FROM NORTHERN MISSOURI. IMPRESSIVE TEMPERATURE DROP OF 20 DEGREES/HOUR WITH FROPA. HAVE UPDATED IOWA ZONES TO FRESHEN WORDING WITH COLD FRONT EXPECTED TO BE RIGHT AROUND THE MISSISSIPPI BY 18Z. WILL HOLD OFF FOR A BIT LONGER ON ILLINOIS ZONES. EXPECT IOWA ZONES TO BE UPDATED BY 1730Z. NC
The office that day
Everything else NWS Quad Cities, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 11, 12:27 PM CST | Severe Thunderstorm Warning | DVN | Hancock | 48 min |
| Feb 11, 1:45 PM CST | Severe Thunderstorm Warning | DVN | Stephenson | 35 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 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.