Alert archive / Iowa / Severe Thunderstorm Warnings in 1996

Severe Thunderstorm Warning 97, NWS Des Moines, IA

October 16, 1996Emmet County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Oct 16, 1996, 11:26 PM CDT for Emmet County, Iowa. It was in force for 29 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: Oct 16, 1996, 11:26 PM CDT (04:26 UTC)
Expired: Oct 16, 1996, 11:55 PM CDT
In force: 29 min
Issued by: NWS Des Moines, IA
Area: Whole counties

County Emmet County, IA

The radar

The Sioux Falls radar (KFSD), 167 km from the middle of the area, began a volume at 04:26 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
Oct 16, 11:45 PM CDT	Thunderstorm Wind 55	Estherville, 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 nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 4.4 hours before the alert went out and 185 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: 809 J/kg
Mixed-layer CIN: -25 J/kg
Mixed-layer LCL: 1117 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 64 m²/s²
0-3 km storm-relative helicity: 200 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 4.4

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 170427
SVRDSM
IAC063-170455-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1126 PM CDT WED OCT 16 1996

* SEVERE THUNDERSTORM WARNING FOR
  EMMET COUNTY - NORTHWEST IOWA

* UNTIL 1155 PM CDT
 
* SOME LOCATIONS AFFECTED
    ESTHERVILLE
    RINGSTEAD
    ARMSTRONG
    WALLINGFORD

* AT 1125 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM APPORACHING
  THE EMMET-DICKINSON COUNTY BORDER 20 MILES NORTHEAST OF
  SPENCER...MOVING NORTHEAST AT 45 MPH.

* THE STORM WILL BE NEAR ESTHERVILLE BY 1135 PM AND ARMSTRONG BY
  1145 PM..

THIS IS A DANGEROUS STORM.  DO NOT GO OUTDOORS. WIND GSUST TO 65 MPH
ARE LIKELY WITH THIS STORM.  WATCH FOR DOWNED TFREES AND POWER LINES.

PYTLAK

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, Oct 16, 6:18 PM CDT, 5 hours 8 minutes before

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-170300-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
617 PM CDT WED OCT 16 1996

HAZARD...ISOLATED SEVERE THUNDERSTORMS PRODUCING HAIL UP TO ONE INCH
IN DIAMETER...WIND GUSTS TO 50 MPH...AND UP TO 2 INCHES OF RAIN.

AREA OF CONCERN...ALL OF CENTRAL IOWA.

TIMING DETAILS...THUNDERSTORMS WILL DEVELOP RAPIDLY OVER NORTHWEST
IOWA AFTER 800 PM AND SPREAD SOUTHEAST INTO THE REST OF THE STATE BY
200 AM.

METEOROLOGICAL COMMENTS...INSTABILITY HAS INCREASED SINCE EARLY
AFTERNOON OVER NORTHWEST IOWA...WHERE LIFTED INDICES HAVE FALLEN TO
AROUND MINUS 9. A STRONG COLD FRONT COUPLED WITH COOLING IN THE UPPER
LEVELS OF THE ATMOSPHERE WILL CONTRIBUTE TO STRONG THUNDERSTORM
DEVELOPMENT TONIGHT. SOUTH WINDS AT 5000 FEET WILL INCREASE TO AROUND
50 MPH TONIGHT...FEEDING WARM MOIST AIR INTO THE FRONT AND SUSTAINING
THUNDERSTORMS WELL INTO THE NIGHT. BECAUSE OF THE DEGREE OF COOLING
ALOFT AND SOME UPPER LEVEL WIND SHEAR...LARGE HAIL IS THE MAIN SEVERE
WEATHER HAZARD. LOCALIZED HEAVY RAIN IS ALSO LIKELY AS THE COLD FRONT
SLOWS DOWN ACROSS IOWA OVERNIGHT.

THERE IS CONSIDERABLE WIND SHEAR IN THE MID LEVELS OF THE ATMOSPHERE.
IT DOES NOT APPEAR THIS SHEAR WILL TRANSLATE TO THE SURFACE AT THIS
TIME. HOWEVER...IF IT DOES...THE THREAT OF AN ISOLATED TORNADO OR TWO
WOULD ALSO INCREASE OVERNIGHT.

PRECAUTIONS...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR MUCH OF
NORTH CENTRAL AND NORTHWEST IOWA UNTIL 1100 PM...WITH A TORNADO WATCH
IN EFFECT FOR MOST OF EASTERN NEBRASKA. MORE WATCHES MAY BE NEEDED
LATER TONIGHT OVER IOWA. LOCAL SPOTTER GROUPS SHOULD REMAIN ON ALERT
FOR ACTIVATION.

PYTLAK

Special weather statement, Oct 16, 9:19 PM CDT, 2 hours 7 minutes before

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-170600-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
920 PM CDT WED OCT 16 1996

HAZARD...ISOLATED SEVERE THUNDERSTORMS PRODUCING HAIL UP TO ONE INCH
IN DIAMETER...WIND GUSTS TO 50 MPH...AND UP TO 2 INCHES OF RAIN.

AREA OF CONCERN...ALL OF CENTRAL IOWA.

TIMING DETAILS...WIDELY SCATTERED THUNDERSTORMS DEVELOPING OVER FAR
SOUTHERN IOWA WILL BECOME MORE NUMEROUS AND MOVE NORTHEAST AS THE
NIGHT WEARS ON. A LINE OF STRONG THUNDERSTORMS OVER NORTHEAST NEBRASKA
AND SOUTHEAST SOUTH DAKOTA WILL ALSO TRACK ACROSS NORTHERN IOWA
OVERNIGHT.

METEOROLOGICAL COMMENTS...SEVERAL SEVERE THUNDERSTORMS HAVE BEEN
REPORTED THIS EVENING OVER NEBRASKA...SOUTHEAST SOUTH DAKOTA AND
MINNESOTA. HOWEVER...INSTABILITY HAS DECREASED SLIGHTLY SINCE
SUNSET...WHICH HAS CAUSED THESE STORMS TO WEAKEN SLIGHTLY. HOWEVER...
SOUTH WINDS AT AROUND 5000FT WERE ALREADY UP TO 40 MPH OVER IOWA AND
WILL INCREASE UP TO 60 MPH OVERNIGHT. THIS WILL CONTINUE TO FEED
THUNDERSTORM DEVELOPMENT THROUGHOUT THE NIGHT AS THE COLD FRONT SLOWLY
PUSHES INTO IOWA. MEANWHILE...TEMPERATURES WILL CONTINUE TO COOL IN
THE UPPER LEVELS OF THE ATMOSPHERE...INCREASING THE POTENTIAL FOR
HAIL. MOST OF THE HAIL SHOULD REMAIN SMALL...BUT THE DEGREE OF
INSTABILITY IS SUFFICIENT TO PRODUCE A FEW LARGER HAILSTONES.

PRECAUTIONS...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR MUCH OF
NORTH CENTRAL AND NORTHWEST IOWA UNTIL 1100 PM...WITH A TORNADO WATCH
IN EFFECT FOR MOST OF EASTERN NEBRASKA. LOCAL SPOTTER GROUPS SHOULD
REMAIN ON ALERT FOR POSSIBLE ACTIVATION OVERNIGHT.

PYTLAK

Special weather statement, Oct 16, 11:08 PM CDT, 18 minutes before

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-170800-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
1107 PM CDT WED OCT 16 1996

HAZARD...ISOLATED SEVERE THUNDERSTORMS PRODUCING HAIL UP TO ONE HALF
INCH IN DIAMETER AND WIND GUSTS TO 65 MPH.

AREA OF CONCERN...NORTHWEST OF A MASON CITY-FORT DODGE-SAC CITY LINE.

TIMING DETAILS...A LINE OF THUNDERSTORMS WILL RACE ACROSS NORTHERN
IOWA BY 300 AM.

METEOROLOGICAL COMMENTS...A LINE OF THUNDERSTORMS HAS EVOLVED INTO A
FAST-MOVING BOW-ECHO...WHICH IS A NOTORIOUS DAMAGING WIND PRODUCER.
THIS LINE WILL RACE ACROSS NORTHERN IOWA AS SOUTH WINDS INCREASE TO 60
MPH AT ABOUT 5000 FEET. DUE TO COOLING ALOFT...SOME OF THE STORMS
COULD ALSO PRODUCE SOME SMALL HAIL.

PRECAUTIONS...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR MUCH OF
NORTH CENTRAL AND NORTHWEST IOWA UNTIL 300 AM. BECAUSE THE STORMS WILL
MOVE ACROSS THE WATCH AREA WITHIN THE NEXT 4 HOURS...SPOTTER
ACTIVATION SHOULD BE UNDERWAY.

PYTLAK

Nearby

Severe Thunderstorm Warnings in Iowa, 1996 Every severe thunderstorm warning in 1996

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.