Alert archive / Iowa / Severe Thunderstorm Warnings in 1991
Severe Thunderstorm Warning 33, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Apr 27, 1991, 1:30 AM CDT for Mahaska County, Iowa. It was in force for 45 min. 3 reports 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
- Apr 27, 1991, 1:30 AM CDT (06:30 UTC)
- Expired
- Apr 27, 1991, 2:15 AM CDT
- In force
- 45 min
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
County Mahaska County, IA
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Apr 27, 1:30 AM CDT | Thunderstorm Wind 87 | Mahaska, IA | |
| Apr 27, 1:40 AM CDT | Thunderstorm Wind 70 | Mahaska, IA | |
| Apr 27, 2:00 AM CDT | Thunderstorm Wind 0 | Mahaska, 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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.
The nearest sounding before it
Topeka, KS (KTOP), launched 00:00Z, 6.5 hours before the alert went out and 364 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- NaN m above ground
- 0-6 km bulk shear
- 79 kt
- 0-1 km storm-relative helicity
- 409 m²/s²
- 0-3 km storm-relative helicity
- 485 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 17.2
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, Apr 27, 12:14 AM CDT, 1 hour 16 minutes before
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</html>Local storm report, Apr 27, 12:45 AM CDT, 45 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE WATERLOO IA
1245 AM CDT SAT ARP 27 1991
EVENT AND LOCATION
HANCOCK COUNTY
1040PM CDT TORNADO REPORTED TO THE WEATHER OFFICE AT 1205
AM CDT.
EXTENSIVE TREE DAMAGE IN GARNER WITH 3 TO 5
TRAILER HOMES TIPPED OVER AND HEAVILY DAMAGED.
SOME HOME DAMAGE WITH NO SERIOUS INJURIES
REPORTED. EVERYONE ACCOUNTED FOR.Special weather statement, Apr 27, 12:49 AM CDT, 41 minutes before
IAZALL-270645- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 1248 AM CDT SAT APR 27 1991 ...AT 1 PM...ONLY A SEVERE THUNDERSTORM WATCH WILL REMAIN IN EFFECT FOR A LARGE PORTION OF SOUTHERN AND EASTERN IOWA UNTIL 4 AM... AT 1231 AM...SHOWERS AND THUNDERSTORMS CONTINUED OVER MUCH OF THE WEST THREE QUARTERS OF IOWA...GENERALLY WEST OF A LINE FROM OTTUMWA TO 30 MILES EAST OF WATERLOO. WITHIN THIS AREA...SCATTERED INTENSE STORMS WERE OVER SOUTH CENTRAL AND CENTRAL IOWA. THE STRONGEST STORMS WERE LOCATED FROM 30 MILES SOUTHWEST OF DES MOINES...TO 45 MILES EAST OF DES MOINES NEAR NEW SHARON...AND 45 MILES NORTHEAST OF DES MOINES NEAR GRINNELL. . THESE INTENSE STORMS HAVE BEEN PRODUCING VERY HEAVY RAIN AND FREQUENT DEADLY LIGHTNING...AND POSSIBLY HAIL AND BRIEF STRONG GUSTY WIND. THE SHOWERS AND STORMS WERE MOVING NORTHEAST AT 45 MILES AN HOUR. PEOPLE IN THE PATH OF THESE INTENSE THUNDERSTORMS SHOULD REMAIN ALERT FOR RAPIDLY CHANGING CONDITIONS...AND BE PREPARED TO SEEK IMMEDIATE SHELTER SHOULD THREATENING WEATHER APPROACH. DM/JAK
Special weather statement, Apr 27, 1:17 AM CDT, 13 minutes before
IAZALL-270710- SPECIAL WEATHER STATEMENT AND IOWA WEATHER UPDATE NATIONAL WEATHER SERVICE DES MOINES IA 118 AM CDT SAT APR 27 1991 ...A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT FOR MUCH OF THE SOUTHEAST QUARTER OF IOWA UNTIL 4 AM... AT 105 AM...SHOWERS AND THUNDERSTORMS CONTINUED OVER MUCH OF THE EAST THREE QUARTERS OF IOWA. MOST OF THE PRECIPITATION WAS EAST OF A LINE FROM LAMONI...TO FORT DODGE...TO 30 MILES WEST OF MASON CITY. WITHIN THIS AREA...SCATTERED INTENSE STORMS WERE LOCATED FROM SOUTH CENTRAL INTO NORTHEAST IOWA. THE STRONGEST STORMS WERE OCCURRING IN A 10 MILE WIDE BAND FROM 35 MILES SOUTHWEST OF OTTUMWA NEAR CENTERVILLE... TO 35 MILES NORTHEAST OF DES MOINES NEAR NEWTON. OTHER STRONG STORMS WERE LOCATED FROM 15 MILES SOUTH OF WATERLOO TO 30 MILES WEST OF CEDAR RAPIDS. THESE INTENSE STORMS WERE PRODUCING BRIEF HEAVY RAIN AND FREQUENT DEADLY LIGHTNING...AND POSSIBLY SOME HAIL AND STRONG GUSTY WINDS. THE SHOWERS AND STORMS WERE MOVING NORTHEAST AT 45 MILES AN HOUR. PEOPLE IN THE PATH OF THESE INTENSE THUNDERSTORMS SHOULD REMAIN ALERT FOR RAPIDLY CHANGING CONDITIONS...AND BE PREPARED TO SEEK IMMEDIATE SHELTER SHOULD THREATENING WEATHER APPROACH. DM/JAK
Special weather statement, Apr 27, 1:21 AM CDT, 9 minutes before
IAZ002-003-006-007-270700- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WATERLOO IA 1215 AM CDT SAT APR 27 1991 ...A SEVERE THUNDERSTORM WATCH FOR PARTS OF NORTHEAST IOWA UNITL 4AM CDT... AT 110 AM CDT AN AREA OF VERY STRONG THUNDERSTORMS EXTENDED FROM ABOUT 10 MILES EAST OF WATERLOO TO ABOUT 15 MILES SOUTHWEST OF WATERLOO. THESE STRONG THUNDERSTORMS WERE PART OF A LARGER AREA OF SHOWERS AND THUNDERSTORMS IN NORTHEAST AND NORTH CENTRAL IOWA THAT WERE GENERALLY WEST OF A LINE FROM THE MINNESOTA BORDER NORTHWEST OF DECORAH TO NEAR INDEPENDENCE. THESE THUNDERSTORMS WERE PRODUCING VERY HEAVY RAIN...STRONG GUSTY WINDS AND DANGEROUS LIGHTNING AS THEY MOVE NORTHEAST AT 40 MILES AN HOUR.
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 26, 7:43 PM CDT | Severe Thunderstorm Warning | DMX | Crawford | 32 min |
| Apr 26, 7:49 PM CDT | Tornado Warning | DMX | Crawford | 26 min |
| Apr 26, 8:19 PM CDT | Tornado Warning | DMX | Sac | 56 min |
| Apr 26, 8:36 PM CDT | Severe Thunderstorm Warning | DMX | Buena Vista | 29 min |
| Apr 26, 8:55 PM CDT | Severe Thunderstorm Warning | DMX | Ringgold | 30 min |
| Apr 26, 9:19 PM CDT | Severe Thunderstorm Warning | DMX | Decatur | 35 min |
| Apr 26, 9:19 PM CDT | Severe Thunderstorm Warning | DMX | Clarke | 41 min |
| Apr 26, 9:46 PM CDT | Severe Thunderstorm Warning | DMX | Polk, Warren | 44 min |
| Apr 26, 10:59 PM CDT | Severe Thunderstorm Warning | DMX | Lucas, Wayne | 31 min |
| Apr 26, 11:18 PM CDT | Tornado Warning | DMX | Wayne | 27 min |
| Apr 26, 11:23 PM CDT | Tornado Warning | DMX | Lucas | 37 min |
| Apr 27, 12:02 AM CDT | Severe Thunderstorm Warning | DMX | Mahaska, Marion, Monroe | 28 min |
| Apr 27, 2:04 AM CDT | Tornado Warning | DMX | Iowa | 41 min |
| Apr 27, 2:04 AM CDT | Tornado Warning | DMX | Keokuk | 15 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 1991Every severe thunderstorm warning in 1991
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.