Alert archive / Nebraska / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 139, NWS Sioux Falls, SD

September 18, 1997Dakota County, Dixon County, Nebraska

NWS Sioux Falls, SD issued this severe thunderstorm warning at Sep 18, 1997, 10:28 PM CDT for Dakota County, Dixon County, Nebraska. It was in force for 47 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: Sep 18, 1997, 10:28 PM CDT (03:28 UTC)
Expired: Sep 18, 1997, 11:15 PM CDT
In force: 47 min
Issued by: NWS Sioux Falls, SD
Area: Whole counties

Counties Dakota County, NE, Dixon County, NE

The radar

The Sioux Falls radar (KFSD), 127 km from the middle of the area, began a volume at 03:30 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
Sep 18, 11:23 PM CDT	Hail 0.75	Willis, NE

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
Sep 18, 9:15 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 3.5 hours before the alert went out and 128 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: 2553 J/kg
Mixed-layer CIN: -28 J/kg
Mixed-layer LCL: 1613 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 60 m²/s²
0-3 km storm-relative helicity: 160 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 6.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFSD 190329 RRA
SVRFSD
NEC043-051-190415-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1028 PM CDT THU SEP 18 1997

* SEVERE THUNDERSTORM WARNING FOR
  DAKOTA COUNTY IN NORTHEASTERN NEBRASKA
  EASTERN DIXON COUNTY IN NORTHEASTERN NEBRASKA

* UNTIL 1115 PM CDT
 
* SOME AREAS AFFECTED
  WILLIS                   AROUND 1025 PM CDT
  JACKSON                  AROUND 1030 PM CDT
  HUBBARD                  AROUND 1035 PM CDT
  HOMER                    AROUND 1045 PM CDT
  SOUTH SIOUX CITY         AROUND 1045 PM CDT
  DAKOTA CITY              AROUND 1045 PM CDT

* AT 1025 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A SEVERE THUNDERSTORM 16 MILES WEST OF SIOUX CITY  OR 4 MILES WEST
  OF WILLIS MOVING EAST AT 35 MPH.

  THIS WARNING REPLACES THE ORIGINAL WARNING FOR DIXON COUNTY.
 
WHEN THUNDERSTORMS ARE OCCURRING...PEOPLE SHOULD MOVE INSIDE A
STRONG BUILDING.  DO NOT STAND BY WINDOWS.  DO NOT USE TELEPHONES OR
ELECTRICAL APPLIANCES UNTIL THE STORM HAS PASSED UNLESS IN AN
EMERGENCY.  MOTORISTS SHOULD NOT DRIVE INTO LOW WATER CROSSINGS.

RSR

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 Sep 18, 9:05 PM CDT, 1 hour 23 minutes earlier.

Area forecast discussion, Sep 18, 9:05 PM CDT, 1 hour 23 minutes before

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
905 PM CDT THU SEP 18 1997

EARLIER TRIED TO FINE TUNE PREV FCST TO TAKE OUT SVR FOR AREA N AND W
OF SIOUX FALLS BUT KEEP IT TO S AND E TNGT. SUPERCELL NEAR YANKTON
PRODUCING 1 INCH HAIL AND ARND 60 MPH WINDS DVLPG SEWD INTO NEB ATTM.
MORE SCT SHWRS/ISOLD TSTMS SHUD DVLPG ENE INTO AREA LATE TNGT AND FRI
MRNG AS FNT OVERRUNS TO SOME EXTENT WITH APPROACH OF MAIN UPR TROF.
UPPD NLY WNDS TO 15 TO 25 MPH IN MUCH OF CWA FOR FRI FM PREV FCST.

.FSD...NONE
RYRHOLM

In the hours before

Local storm report, Sep 18, 9:35 PM CDT, 53 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE  SIOUX FALLS SD
935 PM CDT THU SEP 18 1997

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0840 PM    4 1/2 N YANKTON           SD   0.75 INCH HAIL
09/18/97   YANKTON                        REPORT RECIEVED FROM
                                          CIVIL DEFENSE

0843 PM    YANKTON                   SD   65 MPH WIND GUST
09/18/97   YANKTON                        REPORTED BY KYNT RADIO

0843 PM    YANKTON                   SD   0.75 INCH HAIL
09/18/97   YANKTON                        REPORTED BY KYNT RADIO

CJ

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 18, 9:45 PM CDT	Severe Thunderstorm Warning	FSD	Dixon	45 min

Nearby

Severe Thunderstorm Warnings in Nebraska, 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.