Alert archive / Iowa / Severe Thunderstorm Warnings in 1996

Severe Thunderstorm Warning 91, NWS Des Moines, IA

July 29, 1996Calhoun County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 29, 1996, 3:41 PM CDT for Calhoun County, Iowa. It was in force for 29 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 29, 1996, 3:41 PM CDT (20:41 UTC)
Expired: Jul 29, 1996, 4:10 PM CDT
In force: 29 min
Issued by: NWS Des Moines, IA
Area: Whole counties

County Calhoun County, IA

The radar

The Des Moines radar (KDMX), 105 km from the middle of the area, began a volume at 20:43 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.

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 8.7 hours before the alert went out and 186 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: 498 J/kg
Mixed-layer CIN: -161 J/kg
Mixed-layer LCL: 945 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 97 m²/s²
0-3 km storm-relative helicity: 152 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.8

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 292042
SVRDSM
IAC025-292110-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
341 PM CDT MON JUL 29 1996

* SEVERE THUNDERSTORM WARNING FOR
  NORTHERN CALHOUN COUNTY - WEST CENTRAL IOWA

* UNTIL 410 PM CDT
 
* SOME LOCATIONS AFFECTED
    MANSON
    ROCKWELL CITY

* AT 335 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM 20 MILES
  WEST OF FORT DODGE OR NEAR MANSON MOVING SOUTHEAST AT 25 MPH.

* THE STORM@ WILL BE NORTHEAST OF ROCKWELL CITY AT 350 PM CDT.

SEVERE THUNDERSTORMS CAN AND DO PRODUCE TORNADOES.  TAKE COVER NOW.


SCHAFER

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, Jul 29, 11:04 AM CDT, 4 hours 37 minutes before

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-292100-

CENTRAL IOWA THUNDERSTORM OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE DES MOINES IA
1105 AM CDT MON JUL 29 1996

HAZARD...ISOLATED THUNDERSTORMS WITH HAIL UP TO GOLFBALL SIZE AND
STRONG WINDS IN EXCESS OF 60 MPH.

AREA OF CONCERN...SOUTHWESTERN HALF STATE FROM SIOUX CITY TO AMES TO
BURLINGTON.

TIMING DETAILS...200 PM TO 800 PM.

METEOROLOGICAL COMMENTS...
INSTABILITY - -2 TO -5  WITH EXPECTED TO INCREASE TO -6 TO -10.
DEWPOINTS   - EXPECTED TO INCREASE TO UPPER 60 TO LOWER 70S.
CAPE        - INCREASE TO 3000 TO 4000 J/KG.

WINDS ALOFT ARE EXPECTED TO INCREASE FURTHERING AIDING THE THE
DEVELOPMENT OF STORMS.  WITH SOUTHERLY OR LIGHT NORTH WINDS AT SURFACE
AND STRONG WEST TO NORTHWEST WINDS ALOFT WILL PRODUCE STORM RELATIVE
SHEAR WITH THE SMALL POSSIBILITY OF TORNADOES.

PRECAUTIONS...THE POSSIBILITY OF SEVERE WEATHER IS A LITTLE HIGHER
THIS AFTERNOON AND EVENING THAN IN PREVIOUS DAYS...SO EMERGENCY
MANAGERS SHOULD MONITOR OUTLOOKS AND SHORT TERM FORECASTS CLOSELY. THE
NEXT STATEMENT WILL BE ISSUED AROUND 400 PM.

FORSTER

Special weather statement, Jul 29, 12:03 PM CDT, 3 hours 38 minutes before

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-291800-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
1150 AM CDT MON JUL 29 1996

...NO WATCHES IN AFFECT FOR THE STATE OF IOWA...

DUE TO A COMPUTER GLITCH IN THE COMMUNICATION SECTION OF THE SYSTEM
SEVERE WEATHER WATCHES FROM SUNDAY JULY 28TH WERE RESENT OVER THE
WEATHER WIRE SYSTEM.  PLEASE IGNORE THESE PRODUCTS...HOWEVER SEVERE
WEATHER IS A POSSBILITY LATER ON TODAY SO PAY ATTENTION TO THE DATE
AND TIME ON THE PRODUCT.

FORSTER

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 29, 2:41 PM CDT	Severe Thunderstorm Warning	DMX	Pocahontas	29 min
Jul 29, 3:00 PM CDT	Severe Thunderstorm Warning	DMX	Adair	30 min
Jul 29, 3:25 PM CDT	Severe Thunderstorm Warning	DMX	Madison	35 min
Jul 29, 4:27 PM CDT	Tornado Warning	DMX	Greene	43 min
Jul 29, 5:04 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Decatur	41 min
Jul 29, 5:52 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Union	53 min

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.