Alert archive / Iowa / Severe Thunderstorm Warnings in 1991
Severe Thunderstorm Warning 16, NWS Quad Cities, IA
NWS Quad Cities, IA issued this severe thunderstorm warning at Apr 8, 1991, 2:56 PM CDT for Clayton County, Delaware County, Iowa. It was in force for 64 min. 5 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
- Apr 8, 1991, 2:56 PM CDT (19:56 UTC)
- Expired
- Apr 8, 1991, 4:00 PM CDT
- In force
- 64 min
- Issued by
- NWS Quad Cities, IA
- Area
- Whole counties
Counties Clayton County, IA, Delaware County, IA
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Apr 8, 3:05 PM CDT | Thunderstorm Wind 0 | Clayton, IA | |
| Apr 8, 3:15 PM CDT | Thunderstorm Wind 0 | Clayton, IA | |
| Apr 8, 3:16 PM CDT | Thunderstorm Wind 0 | Delaware, IA | |
| Apr 8, 3:30 PM CDT | Tornado F0 | Delaware, IA | |
| Apr 8, 3:52 PM CDT | Thunderstorm Wind 0 | Delaware, 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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.
The nearest sounding before it
Green Bay/Straub, WI (KGRB), launched 12:00Z, 7.9 hours before the alert went out and 331 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 892 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 38 m²/s²
- 0-3 km storm-relative helicity
- -21 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, Apr 8, 2:42 PM CDT, 14 minutes before
IAZ008-ILZ001-WIZ018-082045- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DUBUQUE IA 242 PM CDT MON APR 8 1991 ...SEVERE THUNDERSTORM WATCH UNTIL 9 PM CDT... ...STRONG THUNDERSTORMS HEADING FOR THE TRI-STATE... AT 230 CDT AN AREA OF STRONG THUNDERSTORMS WERE LOCATED 15 MILES WEST OF THE COUNTIES OF CLAYTON...DELAWARE AND JONES COUNTIES OR ABOUT 60 MILES WEST OF DUBUQUE. THE AREA OF THUNDERSTORMS WAS MOVING EAST AT 30 MILES AN HOUR AND WILL MOVE INTO THE COUNTIES OF CLAYTON...DELAWARE AND JONES COUNTIES BETWEEN 300 PM AND 330 PM CDT. THESE THUNDERSTORMS ARE CAPABLE OF PRODUCING STRONG GUSTY WINDS 45 TO 50 MILES AN HOUR...HEAVY RAIN...SMALL HAIL AND DEADLY LIGHTINING. IF Y-OUR IN THE PATH OF THESE THUNDERSTORMS SEEK SHELTER AT ONCE. HINNERS NNNN
The office that day
Everything else NWS Quad Cities, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 8, 3:20 PM CDT | Severe Thunderstorm Warning | DVN | Jackson, Jones | 40 min |
| Apr 8, 3:28 PM CDT | Tornado Warning | DVN | Dubuque, Jones | 32 min |
| Apr 8, 3:43 PM CDT | Severe Thunderstorm Warning | DVN | Jackson | 62 min |
| Apr 8, 3:34 PM CDT | Tornado Warning | DVN | Grant | 26 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 1991Every severe thunderstorm warning in 1991
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.