Alert archive / Iowa / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 119, NWS Sioux Falls, SD

August 14, 1997Woodbury County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 14, 1997, 9:31 PM CDT for Woodbury County, Iowa. It was in force for 44 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: Aug 14, 1997, 9:31 PM CDT (02:31 UTC)
Expired: Aug 14, 1997, 10:15 PM CDT
In force: 44 min
Issued by: NWS Sioux Falls, SD
Area: Whole counties

County Woodbury County, IA

The radar

The Omaha radar (KOAX), 122 km from the middle of the area, began a volume at 02:37 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
Aug 14, 9:40 PM CDT	Thunderstorm Wind 52	Sergeant Bluff, 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Aug 14, 8:15 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 2.5 hours before the alert went out and 122 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1810 J/kg
Mixed-layer CIN: -28 J/kg
Mixed-layer LCL: 837 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 83 m²/s²
0-3 km storm-relative helicity: 101 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 3.5

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KFSD 150232 RRA
SVRFSD
IAC193-150315-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
931 PM CDT THU AUG 14 1997

* SEVERE THUNDERSTORM WARNING FOR
  WESTERN WOODBURY COUNTY IN NORTHWESTERN IOWA

* UNTIL 1015 PM CDT
 
* SOME AREAS AFFECTED
  MORNINGSIDE              AROUND 935 PM CDT
  SERGEANT BLUFF           AROUND 935 PM CDT
  SALIX                    AROUND 935 PM CDT
  SLOAN                    AROUND 935 PM CDT
  BRONSON                  AROUND 940 PM CDT
  HORNICK                  AROUND 945 PM CDT
  CLIMBING HILL            AROUND 950 PM CDT

* AT 926 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  DAMAGING WINDS 10 MILES SOUTHWEST OF SIOUX CITY OR 6 MILES
  SOUTHWEST OF SERGEANT BLUFF MOVING EAST AT 40 MPH.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55 MPH...
DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.  FOR YOUR
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. REMEMBER SEVERE THUNDERSTORMS CAN PRODUCE
TORNADOES WITH LITTLE OR NO ADVANCED WARNING. DO NOT TAKE THIS
STORM LIGHTLY.

BR

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 Sioux Falls, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 14, 8:26 PM CDT, 1 hour 5 minutes earlier.

Area forecast discussion, Aug 14, 8:26 PM CDT, 1 hour 5 minutes before

SOUTH DAKOTA/NORTHWEST IOWA/SOUTHWEST MINNESOTA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
825 PM CDT THU AUG 14 1997

THUNDERSTORMS FIRING AHD OF SLOW MOVING SFC TROF...WITH STRONGEST STORMS
EXPECTED TO SKIRT SOUTHERN MOST COUNTIES OF CWA IN NE NEB AND NW IA.
STRONGEST STORMS ARE RUNNING PARALLEL TO AXIS OF SFC MOISTURE CONVRG.
NO UPDATES EXPECTED EXCEPT FOR MENTION OF SEVERE THUNDERSTORM WATCH IN
AFFECTED COUNTIES.

.FSD...NONlE

MC MAHON

In the hours before

Special weather statement, Aug 14, 3:54 PM CDT, 5 hours 37 minutes before

SDZ012-024-025-110600-

NORTHERN HILLS WEEKEND FORECAST
NATIONAL WEATHER SERVICE RAPID CITY SD
200 PM MDT THU AUG 14 1997

...WEEKEND OUTLOOK FOR THE NORTHERN HILLS...

EXPECT WINDY AND COOL WEATHER THIS WEEKEND WITH SCATTERED SHOWERS.
A COLD FRONT WILL MOVE SOUTH ACROSS THE BLACK HILLS AREA FRIDAY.
THIS WILL BE FOLLOWED BY COOLER AIR AND BRISK NORTHWEST WINDS. A
DRY DAY IS FORECAST FRIDAY BUT SCATTERED SHOWERS AND THUNDERSTORMS
SHOULD DEVELOP FOR SATURDAY...AND MAY LINGER INTO SUNDAY.

HIGHS FRIDAY WILL BE AROUND 80 ALONG THE NORTHERN FOOT HILLS WITH
70S IN THE BLACK HILLS. HIGHS SATURDAY AND SUNDAY SHOULD REACH THE
LOWER TO MID 70S ALONG THE NORTHERN FOOT HILLS...BUT ONLY MID TO
UPPER 60S ARE EXPECTED IN THE BLACK HILLS. LOWS ARE GOING TO BE IN
THE MID 40S TO THE MID 50S.

MJB

Nearby

Severe Thunderstorm Warnings in Iowa, 1997 Every severe thunderstorm warning in 1997

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.