Alert archive / Iowa / Severe Thunderstorm Warnings in 1990
Severe Thunderstorm Warning 105, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 18, 1990, 8:40 AM CDT for Sioux County, Iowa. It was in force for 35 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 18, 1990, 8:40 AM CDT (13:40 UTC)
- Expired
- Jul 18, 1990, 9:15 AM CDT
- In force
- 35 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Whole counties
County Sioux County, IA
The radar
The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 18, 9:20 AM CDT | Hail 1.75 | Sioux, 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
Omaha, NE (KOAX), launched 12:00Z, 1.7 hours before the alert went out and 197 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
- 3632 m above ground
- 0-6 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- 111 m²/s²
- 0-3 km storm-relative helicity
- 138 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
TTAA00 KFSD 181341
SVRFSD
IAC167-181415-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
840 AM CDT WED JUL 18 1990
THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 915 AM CDT
FOR PEOPLE IN THE FOLLOWING COUNTY...
IN NORTHWEST IOWA
...EASTERN SIOUX
SOME CITIES INCLUDED IN THIS WARNING ARE BOYDEN AND NEWKIRK IOWA.
AT 835 AM CDT RADAR INDICATED A SEVERE THUNDERSTORM 40 MILES SOUTHEAST
OF SIOUX FALLS NEAR SIOUX CENTER IOWA MOVING EAST AT 20 MPH.
AT 830 AM CDT MARBLE OR LARGER SIZE HAIL WAS REPORTED 5 MILES NORTH OF
SIOUX CENTER IOWA.
IF YOU ARE IN THE PATH OF THIS STORM...YOU SHOULD GET TO A
REINFORCED SHELTER. A SEVERE THUNDERSTORM PRODUCES WINDS IN EXCESS
OF 60 MPH...HAIL 3/4 INCH OR LARGER...DEADLY LIGHTNING...AND HEAVY
RAIN THAT CAN QUICKLY FLOOD A LOW LYING AREA.
THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE A TO RNADO WITH LITTLE
OR NO ADVANCE WARNING SO BE ON THE LOOKOUT.
BLOOMWhat 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, Jul 18, 3:08 AM CDT, 5 hours 32 minutes before
SDZ017-018-020-180910- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 307 AM CDT WED JUL 18 1990 AT 3AM CDT THUNDERSTORMS WITH VERY HEAVY RAIN EXTENDED FROM 30 MILES SOUTH OF MITCHELL TO 15 MILES NORTHWEST OF YANKTON SOUTH DAKOTA. STRONGEST THUNDERSTORMS WERE LOCATED 30 MILES NORTHWEST OF YANKTON NEAR TRIPP AND SCOTLAND. THESE STORMS MAY CONTAIN HAIL AND GUSTY WINDS. ANOTHER THUNDERSTORM WAS LOCATED 30 MILES SOUTHWEST OF MITCHELL OR JUST NORTH OF ARMOUR. MOVEMENT WAS EAST AT 10 MILES AN HOUR. SHEEHAN
Special weather statement, Jul 18, 4:11 AM CDT, 4 hours 29 minutes before
SDZ017-018-020-181010- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 410 AM CDT WED JUL 18 1990 STRONG THUNDERSTORMS WITH VERY HEAVY RAIN WERE LOCATED 30 MILES NORTH OF YANKTON NEAR HCENTER POINT...MARION AND FREEMAN SOUTH DAKOTA. THESE THUNDERSTORMS CONTAIN VERY HEAVY RAIN AND FREQUENT LIGHTNING AND ARE CAPABLE OF PRODUCING GUSTY SURFACE WINDS AND SMALL HAIL. MOVEMENT WAS EAST AT 15 MILES AN HOUR. SHEEHAN
Special weather statement, Jul 18, 5:06 AM CDT, 3 hours 34 minutes before
SDZ018-020-181110- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 506 AM CDT WED JUL 18 1990 STRONG THUNDERSTORMS WITH VERY HEAVY RAIN WERE LOCATED FROM 10 MILES SOUTH OF SIOUX FALLS TO 30 MILES SOUTH OF SIOUX FALLS NEAR BERESFORD. ANOTHER STRONG THUNDERSTORM WAS LOCATED 15 MILES SOUTHWEST OF SIOUX FALLS. THESE THUNDERSTORMS CONTAIN VERY HEAVY RAIN AND FREQUENT LIGHTNING AND ARE CAPABLE OF PRODUCING GUSTY SURFACE WINDS AND HAIL. MOVEMENT WAS EAST AT 20 MILES AN HOUR. SHEEHAN
Special weather statement, Jul 18, 6:10 AM CDT, 2 hours 30 minutes before
SDZ018-IAZ001-181210- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 610 AM CDT WED JUL 18 1990 AT 6AM CDT THUNDERSTORMS WITH VERY HEAVY RAIN HAD MOVED INTO NORTHWEST IOWA. THUNDERSTORMS EXTENDED FROM 10 MILES SOUTHEAST OF SIOUX FALLS TO 45 MILES SOUTHEAST OF SIOUX FALLS NEAR SIOUX CENTER IOWA. THESE THUNDERSTORMS CONTAIN VERY HEAVY RAIN AND FREQUENT LIGHTNING AND ARE CAPABLE OF PRODUCING GUSTY SURFACE WINDS AND HAIL. PEOPLE IN NORTHWEST IOWA SHOULD KEEP ON THE ALERT AND BE PREPARED TO SEEK SHELTER IF THREATNING WEATHER APPROACHES. MOVEMENT WAS EAST AT 20 MILES AN HOUR. SHEEHAN
Special weather statement, Jul 18, 7:05 AM CDT, 1 hour 35 minutes before
SDZ018-IAZ001-181310- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 706 AM CDT WED JUL 18 1990 AT 7AM CDT THUNDERSTORMS WITH VERY HEAVY RAIN WERE LOCATED ACROSS NORTHWEST IOWA AND EXTREME SOUTHEAST SOUTH DAKOTA. A LINE OF THUNDERSTORMS EXTENDED FROM 20 MILES NORTHWEST OF SPENCER TO 20 MILES SOUTHWEST OF SPENCER IOWA. ANOTHER THUNDERSTORM WAS LOCATED 10 MILES SOUTH OF SIOUX FALLS. THESE THUNDERSTORMS CONTAIN VERY HEAVY RAIN AND FREQUENT LIGHTNING AND ARE CAPABLE OF PRODUCING GUSTY SURFACE WINDS AND HAIL. PEOPLE IN NORTHWEST IOWA SHOULD KEEP ON THE ALERT AND BE PREPARED TO SEEK SHELTER IF THREATNING WEATHER APPROACHES. MOVEMENT WAS EAST AT 20 MILES AN HOUR. SHEEHEAN
Special weather statement, Jul 18, 8:03 AM CDT, 37 minutes before
SDZ018-IAZ001-181410- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 804 AM CDT WED JUL 18 1990 AT 8 AM CDT THUNDERSTORMS WITH VERY HEAVY RAIN WERE LOCATED 10 MILES SOUTHEAST AND 15 MILES EAST OF SIOUX FALLS SOUTH DAKOTA. THESE THUNDERSTORMS ARE PRODUCING VERY HEAVY RAIN AND MAY BE ACCOMPANIED BY GUSTY SURFACE WINDS AND HAIL. OTHER SHOWERS AND THUNDERSTORMS EXTENDED FROM 20 MILES SOUTHEAST OF SIOUX FALLS TO 20 MILES SOUTH OF SPENCER IOWA. MOVEMENT WAS EAST AT 20 MILES AN HOUR. SHEEHAN
The office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 18, 6:01 AM CDT | Severe Thunderstorm Warning | FSD | Lyon | 29 min |
| Jul 18, 6:26 AM CDT | Severe Thunderstorm Warning | FSD | Lyon, Osceola | 34 min |
| Jul 18, 9:16 AM CDT | Severe Thunderstorm Warning | FSD | O'Brien, Sioux | 29 min |
| Jul 18, 10:54 AM CDT | Severe Thunderstorm Warning | FSD | Sioux | 66 min |
| Jul 18, 12:12 PM CDT | Severe Thunderstorm Warning | FSD | Lyon | 33 min |
| Jul 18, 12:52 PM CDT | Severe Thunderstorm Warning | FSD | Lyon | 38 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 1990Every severe thunderstorm warning in 1990
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.