Alert archive / Iowa / Severe Thunderstorm Warnings in 1994

Severe Thunderstorm Warning 149, NWS Des Moines, IA

July 31, 1994Winnebago County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 31, 1994, 4:54 PM CDT for Winnebago County, Iowa. It was in force for 36 min.

The area

The counties it named.

The facts

Issued: Jul 31, 1994, 4:54 PM CDT (21:54 UTC)
Expired: Jul 31, 1994, 5:30 PM CDT
In force: 36 min
Issued by: NWS Des Moines, IA
Area: Whole counties

County Winnebago County, IA

The nearest sounding before it

Minneapolis, MN (KSTC), launched 12:00Z, 9.9 hours before the alert went out and 164 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: 4 J/kg
Mixed-layer CIN: -306 J/kg
Mixed-layer LCL: 1222 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 87 m²/s²
0-3 km storm-relative helicity: 153 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.0

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 31, 4:22 PM CDT, 32 minutes before

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Special weather statement, Jul 31, 4:24 PM CDT, 30 minutes before

IAZ006>011-016>019-026>029-038>040-312225-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WATERLOO IA
422 PM CDT SUN JUL 31 1994

...SEVERE THUNDERSTORM WATCH FOR NORTHEAST AND NORTH CENTRAL IOWA...

A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR ALL OF NORTHEAST AND NORTH
CENTRAL IOWA THROUGH 10 PM. AT 420 PM RADAR INDICATED THUNDERSTORMS
WERE RAPIDLY FORMING ALONG A SURFACE BOUNDARY WHICH WAS LOCATED FROM
ROCHESTER MINNESOTA SOUTHWEST INTO THE MASON CITY AREA. THESE STORMS
HAVE SHOWN RAPID GROWTH DURING THE PAST HOUR AS THEY HAVE CONTINUED
TO BUILD TO THE SOUTHWEST.

FROM 430 THROUGH 530 PM PEOPLE IN THE NORTHWOOD...MANLY...GARNER AND
MASON CITY AREAS SHOULD KEEP A WATCHFUL EYE ON THE SKY. STORMS COULD
RAPIDLY FORM AND BECOME SEVERE WITH LITTLE WARNING. PEOPLE IN
THE OSAGE...ST ANSGAR...NORA SPRINGS AND ROCKFORD AREAS CAN EXPECT
THUNDERSTORMS AFTER 5 PM.

AT SIGNS OF AN IMPENDING STORM...TOWERING THUNDERHEADS...DARKENING
SKIESZ...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.

PABST

Special weather statement, Jul 31, 4:47 PM CDT, 7 minutes before

IAZALL-312245-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
4 30 PM CDT SUN JUL 31 1994

A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR PORTIONS OF NORTHERN AND
CENTRAL IOWA UNTIL 10 PM THIS SUNDAY EVENING...

AT 4 30 PM CDT...AN AREA OF INTENSE THUNDERSTORMS HAD DEVELOPED IN SOUTH
CENTRAL AND SOUTHEAST MINNESOTA.  A FEW SHOWER AND THUNDERSTORMS OF
LESSER INTENSITY EXTENDED INTO NORTH CENTRAL IOWA AND WERE LOCATED NEAR
BUFFALO CENTER AND NORTHWOOD.

MOVEMENT OF THE THUNDERSTORMS WAS NOT DETERMINED DUE TO THEIR RECENT
DEVELOPMENT.

SCOTT

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 31, 7:55 AM CDT	Severe Thunderstorm Warning	DMX	Mitchell	35 min
Jul 31, 5:26 PM CDT	Severe Thunderstorm Warning	DMX	Mitchell	34 min
Jul 31, 5:31 PM CDT	Severe Thunderstorm Warning	DMX	Winnebago	29 min
Jul 31, 6:02 PM CDT	Severe Thunderstorm Warning	DMX	Hancock	28 min
Jul 31, 6:16 PM CDT	Severe Thunderstorm Warning	DMX	Mitchell, Worth	44 min
Jul 31, 6:33 PM CDT	Tornado Warning	DMX	Mitchell	27 min
Jul 31, 6:41 PM CDT	Severe Thunderstorm Warning	DMX	Hancock, Winnebago	34 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.