Alert archive / Iowa / Severe Thunderstorm Warnings in 1994

Severe Thunderstorm Warning 137, NWS Des Moines, IA

July 7, 1994Fayette County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 7, 1994, 7:36 PM CDT for Fayette County, Iowa. It was in force for 39 min.

The area

The counties it named.

The facts

Issued: Jul 7, 1994, 7:36 PM CDT (00:36 UTC)
Expired: Jul 7, 1994, 8:15 PM CDT
In force: 39 min
Issued by: NWS Des Moines, IA
Area: Whole counties

County Fayette County, IA

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 00:00Z, 0.6 hours before the alert went out and 351 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: 2 J/kg
Mixed-layer CIN: -292 J/kg
Mixed-layer LCL: 1127 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: -17 m²/s²
0-3 km storm-relative helicity: -3 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 7, 6:31 PM CDT, 1 hour 5 minutes before

IAZ025-IAZ036-080015-

SPECIAL WEATHER STATEMENT...CORRECTED 3RD PARAGRAPH
NATIONAL WEATHER SERVICE DES MOINES IA
625 PM CDT THU JUL 7 1994

...THE STRONGEST STORMS SHIFT INTO NORTH CENTRAL IOWA...

AT 615 PM CDT...DOPPLER RADAR INDICATED THAT SHOWERS AND THUNDERSTORMS
WERE BECOMING MORE NUMEROUS OVER NORTH CENTRAL AND NORTHEAST IOWA...
WHILE A NARROW BAND OF SHOWERS AND THUNDERSTORMS WAS REFORMING EAST
AND SOUTHEAST OF DES MOINES.

THE STRONGEST STORMS WERE LOCATED NEAR CONRAD...10 MILES NORTH OF
MARHSALLTOWN AND NEAR OSAGE...20 MILES NORTHEAST OF MASON CITY. THESE
STORMS WILL PRODUCE BRIEF VERY HEAVY RAIN...ALONG WITH DEADLY LIGHTNING
AND POSSIBLY WIND GUSTS OF 30 TO 40 MILES AN HOUR.

THE LEADING EDGE OF THE SHOWERS AND STORMS EXTENDED FROM KNOXVILLE
NORTH THROUGH MARSHALLTOWN TO CHARLES CITY AND THEN NORTH INTO SOUTHERN
MINNESOTA. ISOLATED THUNDERSTORMS WERE LOCATED OVER NORTHEAST IOWA
BETWEEN OSAGE AND DECORAH.

THE SHOWERS AND STORMS WERE MOVING NORTHEAST AT 25 MILES AN HOUR.

BARLOW

Special weather statement, Jul 7, 6:59 PM CDT, 37 minutes before

IAZ006>011-016>019-026>029-038>040-080100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
657 PM CDT THU JUL 7 1994

...A TORNADO WATCH CONTINUES UNTIL 8PM...
...A FLASH FLOOD WATCH REMAINS IN EFFECT TONIGHT...

AT 653 PM...WEATHER SERVICE RADAR IN WATERLOO WAS SHOWING AN AREA OF
INTENSE THUNDERSTORMS IN EASTERN GRUNDY AND BUTLER COUNTIES IN ADDITION
TO WESTERN BREMER COUNTY.  THESE THUNDERSTORMS WERE MOVING NORTHEAST AT
25 MPH AND WILL AFFECT THE WATERLOO/CEDAR FALLS METRO AREA...WAVERLY...
DENVER...TRIPOLI AND PLAINFIELD AREAS THROUGH 730 PM.  BY 815 PM...THESE
STORMS WILL MOVE INTO FAYETTE AND SOUTHERN WINNESHIEK COUNTIES.

PERSONS IN THESE AREAS CAN EXPECT VERY HEAVY RAINS ALONG WITH FREQUENT
DEADLY LIGHTNING...STRONG GUSTY WINDS...AND POSSIBLE HAIL WITH THE
PASSAGE OF THESE STORMS DURING THE NEXT HOUR.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 8PM.  CONDITIONS ARE FAVORABLE
IN NORTHEAST AND NORTH CENTRAL IOWA FOR SEVERE THUNDERSTORMS AND
TORNADOES TO DEVELOP.

ALSO A FLASH FLOOD WATCH IS IN EFFECT TONIGHT.  THESE STORMS ARE ALSO
CAPABLE OF PRODUCING VERY HEAVY RAIN IN A SHORT PERIOD OF TIME AND
COULD CAUSE FLASH FLOODING.  AT 645 PM...THE TOWN OF WELLSBURG IN
WESTERN GRUNDY COUNTY REPORTED 1.09 INCHES OF RAINFALL IN A HALF HOUR
PERIOD.

AT SIGNS OF AN IMPENDING STORM...TOWERING THUNDERHEADS...DARKENING
SKIES...LIGHTNING AND INCREASING WINDS...MOVE TO A PLACE OF SAFETY.
TUNE IN NOAA WEATHER RADIO| OR YOUR LOCAL RADIO OR TV STATION FOR
THE LATEST WEATHER INFORMATION.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLASH FLOODING.

TRS

Special weather statement, Jul 7, 7:20 PM CDT, 16 minutes before

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Special weather statement, Jul 7, 7:21 PM CDT, 15 minutes before

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Special weather statement, Jul 7, 7:25 PM CDT, 11 minutes before

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      <div class="status" id="status">Temporary Notice</div>
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        The site you requested is temporarily down for maintenance or an unexpected outage.
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Special weather statement, Jul 7, 7:29 PM CDT, 7 minutes before

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</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 7, 7:16 PM CDT	Tornado Warning	DMX	Chickasaw, Fayette, Winneshiek	29 min
Jul 7, 7:36 PM CDT	Severe Thunderstorm Warning	DMX	Bremer	29 min
Jul 8, 2:00 PM CDT	Tornado Warning	DMX	Adair	15 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1994 Every severe thunderstorm warning in 1994

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.