Alert archive / Iowa / Severe Thunderstorm Warnings in 1996

Severe Thunderstorm Warning 85, NWS Des Moines, IA

July 16, 1996Crawford County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 16, 1996, 10:46 PM CDT for Crawford County, Iowa. It was in force for 34 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 16, 1996, 10:46 PM CDT (03:46 UTC)
Expired: Jul 16, 1996, 11:20 PM CDT
In force: 34 min
Issued by: NWS Des Moines, IA
Area: Whole counties

County Crawford County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 3.8 hours before the alert went out and 114 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: 1921 J/kg
Mixed-layer CIN: -74 J/kg
Mixed-layer LCL: 979 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 101 m²/s²
0-3 km storm-relative helicity: 214 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 170346
SVRDSM
IAC047-170420-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1046 PM CDT TUE JUL 16 1996

* SEVERE THUNDERSTORM WARNING FOR
  SOUTHERN CRAWFORD COUNTY - WEST CENTRAL IOWA

* UNTIL 1120 PM CDT
 
* SOME LOCATIONS AFFECTED
    DENISON
    VAIL
    WESTSIDE

* AT 1044 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM 3 MILES NORTH
  OF DENISON OR 70 MILES SOUTHEAST OF SIOUX CITY MOVING EAZST AT 30
  MPH.

* THE STORM WILL BE THROUGH DENISON AT 1050 AND VAIL BY 1105 PM CDT.

THIS IS A DANGEROUS STORM.  DO NOT GO OUTDOORS.




FAB

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 16, 6:51 PM CDT, 3 hours 55 minutes before

IAZ004>007-015>017-023>026-033>037-044>049-057>061-070>074-081>085-
092>096-170250-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
650 PM CDT TUE JUL 16 1996

HAZARD...ISOLATED SEVERE THUNDERSTORMS CAPABLE OF PRODUCING WIND
GUSTS TO 70 MPH...GOLF BALL SIZE HAIL...AND HEAVY RAINFALL.

AREA OF CONCERN...THE MAIN SEVERE WEATHER THREAT WOULD BE ALONG AND
WEST OF A BEDFORD TO CLARION TO MANLY LINE. EAST OF THIS LINE IT
APPEARS THE MAIN THREAT LATER TONIGHT WILL BE WITH HEAVY RAINFALL.

TIMING DETAILS...BETWEEN 8 AND 10 PM WEST OF AN ATLANTIC TO ALGONA
LINE WITH THE MAIN COMPLEX MOVING ACROSS NORTHERN AND CENTRAL IOWA
BETWEEN 10 PM AND MIDNIGHT.

METEOROLOGICAL COMMENTS...A WARM FRONT LOCATED ACROSS SOUTHERN
NEBRASKA EASTWARD THROUGH NORTHEAST KANSAS AND NORTHERN MISSOURI IS
FORECAST TO PUSH NORTHWARD TONIGHT AND BE LOCATED ACROSS NORTHWEST
THROUGH SOUTHEAST IOWA BY WEDNESDAY MORNING.  THE AIR MASS ALONG AND
SOUTH OF THE FRONTAL BOUNDARY IS EXTREMELY UNSTABLE WITH LIFTED
INDICES AROUND MINUS 10 OVER SOUTHERN AND CENTRAL NEBRASKA. LATEST
PROFILER DATA INDICATES A CLASSIC CLOCKWISE TURNING OF THE WINDS IN
THE LOWEST 8,000 FEET OVER PARTS OF CENTRAL AND EASTERN NEBRASKA
WHICH WOULD SUPPORT PERSISTANT ROTATING UPDRAFTS CAPABLE OF PRODUCE
TORNADOES. THE LOW LEVEL SHEAR PROFILE ACROSS WEST AND NORTHWEST
IS MORE UNIDIRECTIONAL WHICH WOULD INFER THE POTENTIAL FOR MORE
STRAIGHT LINE WIND DAMAGE IN THIS AREA LATER THIS EVENING.

THUNDERSTORMS OCCURRING AT THE PRESENT TIME OVER EASTERN NEBRASKA
ARE EXPECTED TO CONSOLIDATE INTO A LARGE COMPLEX OF STORMS LATER
TONIGHT AND PUSH ACROSS THE REMAINDER OF THE STATE. AGAIN IT APPEARS
THE MAIN THREAT OVER CENTRAL AND EASTERN IOWA WOULD BE WITH HEAVY
RAINS LATE TONIGHT INTO WEDNESDAY MORNING WITH THE THREAT OF SEVERE
WEATHER MAINLY CONFINED OVER THE WESTERN THIRD OF THE STATE.

PRECAUTIONS...SPOTTER ACTIVATION MAY BE REQUIRED LATER THIS EVENING
OVER WESTERN IOWA AS THE THUNDERSTORMS CURRENTLY OVER EASTERN
NEBRASKA TRACK EAST OF THE MISSOURI RIVER. KEEP ABREAST OF LATER
STATEMENTS THIS EVENING REGARDING THE THUNDERSTORM POTENTIAL OVER
THE WESTERN HALF OF THE STATE.

SMITH

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 16, 8:14 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	31 min
Jul 17, 12:46 AM CDT	Flash Flood Warning	DMX	Crawford	6 hr
Jul 17, 1:12 AM CDT	Severe Thunderstorm Warning	DMX	Greene	33 min
Jul 17, 2:36 AM CDT	Flash Flood Warning	DMX	Carroll	6 hr
Jul 17, 6:04 AM CDT	Flash Flood Warning	DMX	Carroll, Crawford	4 hr

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.