Alert archive / Iowa / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 21, NWS Quad Cities, IA
NWS Quad Cities, IA issued this severe thunderstorm warning at May 16, 1999, 10:40 PM CDT for Henry County, Johnson County, Washington County, Iowa. It was in force for 45 min. 3 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 16, 1999, 10:40 PM CDT (03:40 UTC)
- Expired
- May 16, 1999, 11:25 PM CDT
- In force
- 45 min
- Issued by
- NWS Quad Cities, IA
- Area
- Whole counties
Counties Henry County, IA, Johnson County, IA, Washington County, IA
The radar
The Quad Cities radar (KDVN), 92 km from the middle of the area, began a volume at 03:40 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 16, 11:00 PM CDT | Thunderstorm Wind | Washington, IA | Severe winds tore the metal roof from a welding shop and blew it into a neighboring business. |
| May 16, 11:00 PM CDT | Thunderstorm Wind | Iowa City, IA | Severe thunderstorm winds downed trees. |
| May 16, 11:05 PM CDT | Thunderstorm Wind | West Chester, IA | Severe thunderstorm winds downed tree branches onto the roofs of at least 2 houses. |
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, 9:00 PM CDT | Tornado Watch | SPC | 6 hr |
The nearest sounding before it
Davenport, (KDVN), launched 00:00Z, 3.7 hours before the alert went out and 98 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.
999 WUUS1 KMLI 170342 RRA SVRMLI IAC087-103-113-183-170425- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE QUAD CITIES IA IL 1040 PM CDT SUN MAY 16 1999 THE NATIONAL WEATHER SERVICE IN QUAD CITIES IA HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... HENRY COUNTY IOWA IN SOUTHEASTERN IOWA JOHNSON COUNTY IN EAST CENTRAL IOWA LINN COUNTY IN EAST CENTRAL IOWA WASHINGTON COUNTY IN SOUTHEASTERN IOWA * UNTIL 1125 PM CDT * AT 1040 PM CDT...DOPPLER RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS EXTENDING FROM NEAR CEDAR RAPIDS TO WEST OF IOWA CITY... MOVING EAST AT 30 MPH. DAMAGING WINDS IN EXCESS OF 70 MPH ARE LIKELY. GO INSIDE A STURDY BUILDING AND STAY AWAY FROM WINDOWS A TORNADO WATCH IS IN EFFECT. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE WARNING. MCCLURE/KINNEY
The office that day
Everything else NWS Quad Cities, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 16, 7:09 PM CDT | Severe Thunderstorm Warning | DVN | Dubuque, Jones | 61 min |
| May 16, 7:39 PM CDT | Flash Flood Warning | DVN | Buchanan | 4 hr |
| May 16, 8:51 PM CDT | Severe Thunderstorm Warning | DVN | Dubuque | 49 min |
| May 16, 9:10 PM CDT | Tornado Warning | DVN | Dubuque | 35 min |
| May 16, 9:46 PM CDT | Tornado Warning | DVN | Dubuque | 49 min |
| May 16, 10:13 PM CDT | Tornado Warning | DVN | Benton | 47 min |
| May 16, 10:34 PM CDT | Severe Thunderstorm Warning | DVN | Keokuk | 46 min |
| May 16, 10:40 PM CDT | Severe Thunderstorm Warning | DVN | Linn | 45 min |
| May 16, 10:47 PM CDT | Severe Thunderstorm Warning | DVN | Des Moines, Lee, Louisa | 63 min |
| May 16, 10:47 PM CDT | Severe Thunderstorm Warning | DVN | Cedar, Muscatine | 63 min |
| May 16, 10:54 PM CDT | Tornado Warning | DVN | Dubuque | 51 min |
| May 16, 11:15 PM CDT | Severe Thunderstorm Warning | DVN | Clinton, Jackson | 50 min |
| May 16, 11:28 PM CDT | Severe Thunderstorm Warning | DVN | Scott | 47 min |
| May 16, 11:36 PM CDT | Flash Flood Warning | DVN | Dubuque | 6 hr |
| May 16, 11:36 PM CDT | Flash Flood Warning | DVN | Buchanan, Delaware | 6 hr |
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.