Alert archive / Iowa / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 68, NWS Des Moines, IA

May 15, 1998Bremer County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 15, 1998, 5:40 PM CDT for Bremer County, Iowa. It was in force for 35 min. 1 report 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: May 15, 1998, 5:40 PM CDT (22:40 UTC)
Expired: May 15, 1998, 6:15 PM CDT
In force: 35 min
Issued by: NWS Des Moines, IA
Area: Whole counties

County Bremer County, IA

The radar

The La Crosse radar (KARX), 148 km from the middle of the area, began a volume at 22:40 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.

What was reported inside it

Time	Report	Where	Remark
May 15, 6:00 PM CDT	Thunderstorm Wind 65	Sumner, 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 15, 3:00 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.7 hours before the alert went out and 253 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: 1571 J/kg
Mixed-layer CIN: -84 J/kg
Mixed-layer LCL: 642 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 179 m²/s²
0-3 km storm-relative helicity: 180 m²/s²
Significant tornado parameter: 0.9
Supercell composite: 6.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 152240 RRA
SVRDSM
IAC017-152315-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
540 PM CDT FRI MAY 15 1998

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  BREMER COUNTY IN NORTHEASTERN IOWA

* UNTIL 615 PM CDT

* AT 539 PM CDT... DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 16
  MILES NORTH NORTHWEST OF WATERLOO OR 9 MILES SOUTH OF PLAINFIELD
  MOVING NORTH NORTHEAST AT 45 MPH.

* THIS STORM CAN BE EXPECTED NEAR...
   PLAINFIELD         BY 545 PM CDT
   TRIPOLI            BY 548 PM CDT
   FREDRICKA          BY 553 PM CDT

GO INSIDE A STURDY BUILDING AND STAY AWAY FROM WINDOWS! A TORNADO
WAT
CH IS IN EFFECT. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO
PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE WARNING.

THIS EXTENDS THE SEVERE THUNDERSTORM WARNING THAT WAS ALREADY IN
EFFECT FOR BREMER COUNTY.

GF/BSS

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

Local storm report, May 15, 11:49 AM CDT, 5 hours 51 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
1149 AM CDT FRI MAY 15 1998

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0935 AM    15 SSW ATLANTIC           IA   65 MPH TSTM GUST
05/15/98   CASS

0941 AM    GRISWOLD                  IA   75 MPH TSTM GUST
05/15/98   CASS                           LARGE BRANCHES DOWN

0958 AM    AUDUBON                   IA   WIND DAMAGE
05/15/98   AUDUBON                        POWER OUT...NUMEROUS TREE
                                          BRANCHES DOWN

0958 AM    3 W AUDUBON               IA   WIND DAMAGE
05/15/98   AUDUBON                        BARN BLOWN DOWN...TREES
                                          DOWN

1002 AM    DENISON MUNI ARPT         IA   60 MPH TSTM GUST
05/15/98   CRAWFORD                       DENISON AWOS AUTOMATED
                                          OBSERVATION

1012 AM    3 SE BUCK GROVE           IA   WIND DAMAGE
05/15/98   CRAWFORD                       ROOF TAKEN OFF BARN

1016 AM    CARROLL                   IA   70 MPH TSTM GUST
05/15/98   CARROLL

1019 AM    TEMPLETON                 IA   60 MPH TSTM GUST
05/15/98   CARROLL                        TREES DOWN...POWER OUT
                                          FROM HAM RADIO

1020 AM    DENISON                   IA   WIND DAMAGE
05/15/98   CRAWFORD                       BILLBOARD DOWN WITH DEBRIS

1022 AM    CARROLL NEU ARPT          IA   59 MPH TSTM GUST
05/15/98   CARROLL                        CARROLL AWOS AUTOMATED
                                          OBSERVATION

1032 AM    GLIDDEN                   IA   58 MPH TSTM GUST
05/15/98   CARROLL                        FROM HAM RADIO

SMALL/COGIL

Local storm report, May 15, 11:49 AM CDT, 5 hours 51 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
1149 AM CDT FRI MAY 15 1998

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0935 AM    15 SSW ATLANTIC           IA   65 MPH TSTM GUST
05/15/98   CASS

0941 AM    GRISWOLD                  IA   75 MPH TSTM GUST
05/15/98   CASS                           LARGE BRANCHES DOWN

0958 AM    AUDUBON                   IA   WIND DAMAGE
05/15/98   AUDUBON                        POWER OUT...NUMEROUS TREE
                                          BRANCHES DOWN

0958 AM    3 W AUDUBON               IA   WIND DAMAGE
05/15/98   AUDUBON                        BARN BLOWN DOWN...TREES
                                          DOWN

1002 AM    DENISON MUNI ARPT         IA   60 MPH TSTM GUST
05/15/98   CRAWFORD                       DENISON AWOS AUTOMATED
                                          OBSERVATION

1012 AM    3 SE BUCK GROVE           IA   WIND DAMAGE
05/15/98   CRAWFORD                       ROOF TAKEN OFF BARN

1016 AM    CARROLL                   IA   70 MPH TSTM GUST
05/15/98   CARROLL

1019 AM    TEMPLETON                 IA   60 MPH TSTM GUST
05/15/98   CARROLL                        TREES DOWN...POWER OUT
                                          FROM HAM RADIO

1020 AM    DENISON                   IA   WIND DAMAGE
05/15/98   CRAWFORD                       BILLBOARD DOWN WITH DEBRIS

1022 AM    CARROLL NEU ARPT          IA   59 MPH TSTM GUST
05/15/98   CARROLL                        CARROLL AWOS AUTOMATED
                                          OBSERVATION

1032 AM    GLIDDEN                   IA   58 MPH TSTM GUST
05/15/98   CARROLL                        FROM HAM RADIO

SMALL/COGIL

Special weather statement, May 15, 1:24 PM CDT, 4 hours 16 minutes before

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-152324-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
124 PM CDT FRI MAY 15 1998

HAZARD--ISOLATED TORNADOES...LARGE HAIL GREATER THAN 1 INCH AND
STRAIGHT LINE WINDS GREATER THAN 60 MPH.

AREA OF CONCERN AND TIMING DETAILS--ALL OF CENTRAL IOWA...ESPECIALLY
IN AREAS FROM RED OAK NORTHEAST TOWARD CARROLL...FORT DODGE AND MASON
CITY. THEN SPREADING EAST LATE THIS AFTERNOON INTO REST OF AREA.

PRECAUTIONS--SPOTTER ORGANIZATIONS AND EMERGENCY MANAGEMENT SHOULD
PREPARE FOR ACTIVATION THIS AFTERNOON.  MAINTAIN A WATCH FOR
ADDITIONAL NWS OUTLOOKS AND SHORT TERM FORECASTS.  A SEVERE
THUNDERSTORM WATCH REMAINS IN EFFECT FOR MOST OF NORTH CENTRAL AND
NORTHWEST IOWA UNTIL 300 PM.  ADDITIONAL WATCHES MAY BE REQUIRED
THIS AFTERNOON.

KULA

Special weather statement, May 15, 1:24 PM CDT, 4 hours 16 minutes before

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-152324-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
124 PM CDT FRI MAY 15 1998

HAZARD--ISOLATED TORNADOES...LARGE HAIL GREATER THAN 1 INCH AND
STRAIGHT LINE WINDS GREATER THAN 60 MPH.

AREA OF CONCERN AND TIMING DETAILS--ALL OF CENTRAL IOWA...ESPECIALLY
IN AREAS FROM RED OAK NORTHEAST TOWARD CARROLL...FORT DODGE AND MASON
CITY. THEN SPREADING EAST LATE THIS AFTERNOON INTO REST OF AREA.

PRECAUTIONS--SPOTTER ORGANIZATIONS AND EMERGENCY MANAGEMENT SHOULD
PREPARE FOR ACTIVATION THIS AFTERNOON.  MAINTAIN A WATCH FOR
ADDITIONAL NWS OUTLOOKS AND SHORT TERM FORECASTS.  A SEVERE
THUNDERSTORM WATCH REMAINS IN EFFECT FOR MOST OF NORTH CENTRAL AND
NORTHWEST IOWA UNTIL 300 PM.  ADDITIONAL WATCHES MAY BE REQUIRED
THIS AFTERNOON.

KULA

Special weather statement, May 15, 5:26 PM CDT, 14 minutes before

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-152324-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
526 PM CDT FRI MAY 15 1998

THE TORNADO WATCH FOR MUCH OF CENTRAL AND WESTERN IOWA HAS BEEN
CANCELLED. THE TORNADO WATCH REMAINS IN EFFECT EAST OF A MASON
CITY-OTTUMWA LINE UNTIL 900 PM...AND EAST OF A DECORAH-FAIRFIELD
LINE UNTIL 1100 PM.

STRONG SOUTHWEST WINDS GUSTING UP TO 50 MPH HAVE BEEN REPORTED
IN SOUTHWEST IOWA AS AIR RUSHES INTO THE THUNDERSTORMS FURTHER
EAST. THESE WINDS SHOULD DIMINISH AFTER 700 OR 800 PM...BUT
MOTORISTS SHOULD USE CAUTION.

PYTLAK
KULA

Special weather statement, May 15, 5:26 PM CDT, 14 minutes before

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-152324-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
526 PM CDT FRI MAY 15 1998

THE TORNADO WATCH FOR MUCH OF CENTRAL AND WESTERN IOWA HAS BEEN
CANCELLED. THE TORNADO WATCH REMAINS IN EFFECT EAST OF A MASON
CITY-OTTUMWA LINE UNTIL 900 PM...AND EAST OF A DECORAH-FAIRFIELD
LINE UNTIL 1100 PM.

STRONG SOUTHWEST WINDS GUSTING UP TO 50 MPH HAVE BEEN REPORTED
IN SOUTHWEST IOWA AS AIR RUSHES INTO THE THUNDERSTORMS FURTHER
EAST. THESE WINDS SHOULD DIMINISH AFTER 700 OR 800 PM...BUT
MOTORISTS SHOULD USE CAUTION.

PYTLAK
KULA

The office that day

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

Issued	Product	Office	Counties	Lasted
May 15, 9:18 AM CDT	Severe Thunderstorm Warning	DMX	Taylor	32 min
May 15, 9:28 AM CDT	Severe Thunderstorm Warning	DMX	Cass	37 min
May 15, 9:46 AM CDT	Severe Thunderstorm Warning	DMX	Audubon	34 min
May 15, 9:54 AM CDT	Severe Thunderstorm Warning	DMX	Crawford	36 min
May 15, 10:00 AM CDT	Severe Thunderstorm Warning	DMX	Carroll	35 min
May 15, 10:11 AM CDT	Tornado Warning	DMX	Crawford	34 min
May 15, 10:16 AM CDT	Severe Thunderstorm Warning	DMX	Sac	34 min
May 15, 10:24 AM CDT	Severe Thunderstorm Warning	DMX	Calhoun	36 min
May 15, 12:56 PM CDT	Severe Thunderstorm Warning	DMX	Carroll	34 min
May 15, 1:04 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Sac	31 min
May 15, 1:09 PM CDT	Tornado Warning	DMX	Calhoun	36 min
May 15, 1:16 PM CDT	Severe Thunderstorm Warning	DMX	Humboldt	34 min
May 15, 1:31 PM CDT	Severe Thunderstorm Warning	DMX	Kossuth	34 min
May 15, 1:38 PM CDT	Tornado Warning	DMX	Kossuth	32 min
May 15, 1:42 PM CDT	Severe Thunderstorm Warning	DMX	Pocahontas	33 min
May 15, 1:48 PM CDT	Severe Thunderstorm Warning	DMX	Cass	17 min
May 15, 1:51 PM CDT	Severe Thunderstorm Warning	DMX	Audubon	34 min
May 15, 2:10 PM CDT	Severe Thunderstorm Warning	DMX	Kossuth	35 min
May 15, 2:38 PM CDT	Tornado Warning	DMX	Kossuth	22 min
May 15, 3:03 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Greene	32 min
May 15, 3:22 PM CDT	Severe Thunderstorm Warning	DMX	Webster	33 min
May 15, 3:29 PM CDT	Severe Thunderstorm Warning	DMX	Hamilton	31 min
May 15, 3:37 PM CDT	Tornado Warning	DMX	Wright	33 min
May 15, 3:42 PM CDT	Severe Thunderstorm Warning	DMX	Story	33 min
May 15, 3:51 PM CDT	Severe Thunderstorm Warning	DMX	Wapello	34 min
May 15, 3:54 PM CDT	Severe Thunderstorm Warning	DMX	Sac	36 min
May 15, 3:59 PM CDT	Severe Thunderstorm Warning	DMX	Franklin, Hardin	46 min
May 15, 3:59 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Hancock	46 min
May 15, 4:09 PM CDT	Severe Thunderstorm Warning	DMX	Davis	36 min
May 15, 4:13 PM CDT	Tornado Warning	DMX	Wapello	32 min
May 15, 4:24 PM CDT	Tornado Warning	DMX	Calhoun, Pocahontas	36 min
May 15, 4:40 PM CDT	Severe Thunderstorm Warning	DMX	Humboldt	35 min
May 15, 4:45 PM CDT	Severe Thunderstorm Warning	DMX	Tama	35 min
May 15, 4:48 PM CDT	Severe Thunderstorm Warning	DMX	Kossuth, Palo Alto	47 min
May 15, 4:59 PM CDT	Severe Thunderstorm Warning	DMX	Butler, Grundy	31 min
May 15, 5:00 PM CDT	Severe Thunderstorm Warning	DMX	Black Hawk	35 min
May 15, 5:07 PM CDT	Severe Thunderstorm Warning	DMX	Bremer	33 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1998 Every severe thunderstorm warning in 1998

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; radar from the NEXRAD Level II archive.