Alert archive / Iowa / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 98, NWS Des Moines, IA

July 2, 1999Dallas County, Madison County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 2, 1999, 3:29 PM CDT for Dallas County, Madison County, Iowa. It was in force for 36 min. 5 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: Jul 2, 1999, 3:29 PM CDT (20:29 UTC)
Expired: Jul 2, 1999, 4:05 PM CDT
In force: 36 min
Issued by: NWS Des Moines, IA
Area: Whole counties

Counties Dallas County, IA, Madison County, IA

What was reported inside it

Time	Report	Where
Jul 2, 3:30 PM CDT	Hail 1.75	Earlham, IA
Jul 2, 3:35 PM CDT	Hail 2.75	Earlham, IA
Jul 2, 3:38 PM CDT	Hail 1	Adel, IA
Jul 2, 3:38 PM CDT	Hail 1	Adel, IA
Jul 2, 3:43 PM CDT	Hail 2.75	Dexter, 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
Jul 2, 12:15 PM CDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 8.5 hours before the alert went out and 196 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: 217 J/kg
Mixed-layer CIN: -357 J/kg
Mixed-layer LCL: 1083 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 171 m²/s²
0-3 km storm-relative helicity: 406 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

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.

NWS Des Moines, IA wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 2, 3:24 AM CDT, 12 hours 5 minutes earlier.

Area forecast discussion, Jul 2, 3:24 AM CDT, 12 hours 5 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
324 AM CDT FRI JUL 2 1999

FORECAST CHALLENGES WILL FOCUS ON THUNDERSTORM CHANCES AND TIMING.
CONVECTION OVER NORTHERN NEBRASKA AND SOUTHERN SOUTH DAKOTA FIRING ON
NOSE OF LLJ AND HELPED BY STRONG MID AND UPPER LEVEL WINDS.  VERY
STRONG WAA IS OCCURRING IN THIS AREA AS PER PROFILER DATA SHOWING
DECENT VEERING IN A DEEP LAYER.  THIS ACTIVITY SHOULD SPILL OVER INTO
NORTHWESTERN ZONES THIS MORNING AND CONTINUE TO SLIDE RAPIDLY EAST
WITH QUICK FLOW ALOFT.

PATTERN CHANGE IN THE PROCESS OF OCCURRING WITH HEIGHTS TO RISE OVER
THE EASTERN US AS WESTERN TROUGH DEEPENS.  MODELS SEEM TO HAVE A GOOD
HANDLE ON THE OVERALL TRANSITION WITH THE USUAL DIFFERENCES IN THE
DETAILS.  ETA AND AVN SIMILAR IN PLACEMENT OF SYNOPTIC FEATURES
ALTHOUGH AVN TIMING IS BETTER.  NGM/S EASTERN RIDGE NOT QUITE AS
STRONG ALLOWING SFC FNT TO NEAR STATE BY 48 HOURS.  FEEL STRONGER
EASTERN RIDGE DEPICTED BY AVN/ETA BETTER AS WESTERN TROUGH DEEPENS
AND THEREFORE WILL BLEND THE ETA/AVN FOR THIS PACKAGE.

TODAY WILL SEE CONVECTION SLIDE ACROSS NORTHERN CWA WITH FAIRLY
RAPID PROGRESSION...ALTHOUGH ETA AND MESO ETA HINT AT SOUTHWARD
PROPAGATION IN WESTERN IA.  FOR NOW WILL GO WITH SCT WORDING NW ZONES
AND LEAVE POPS IN REMAINDER OF ZONES AS EXACT MOVEMENT IFFY.  WAA
WILL BE STRONG DURING THE DAY WITH INCREASING MOISTURE HELPING TO
DESTABILIZE THE ATMOSPHERE.  AS PER MANY NATIONAL DISCUSSION...FEEL
MCS TO DEVELOP OVER SOUTHERN SD AND NORTHERN NE THIS EVENING.  THIS
SHOULD MOVE EAST SOUTHEAST INTO THE STATE OVERNIGHT ON THE NOSE OF A
50+ KT LLJ.  BY SATURDAY MORNING...THE MCS IS EXPECTED TO DECAY OVER
AREA AND MOVE EAST LEAVING BEHIND WARM AND HUMID CONDITIONS FOR THE
REMAINDER OF THE HOLIDAY WEEKEND.  CAP SHOULD BE IN PLACE BY LATER
SATURDAY BUT ALWAYS THREAT OF SOMETHING DEVELOPING OUTSIDE THE CAPPED
AREA AND MOVING INTO THE CWA...FOR NOW WILL LEAVE THAT PART OF
FORECAST ALONE.  FWC A TAD WARM TODAY WITH FAN GUIDANCE LOOKING
BETTER AND MORE CONSISTENT.

.DSM...NONE

COGIL

In the hours before

Special weather statement, Jul 2, 11:10 AM CDT, 4 hours 19 minutes before

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-031100-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
1110 AM CDT FRI JUL 2 1999

HAZARD--SCATTERED THUNDERSTORMS WITH A FEW SEVERE THUNDERSTORMS
CAPABLE OF PRODUCING UP TO TWO INCH HAIL AND WIND GUSTS TO 65 MPH.
SOME OF THE SEVERE THUNDERSTORMS COULD PRODUCE A TORNADO.

AREA OF CONCERN AND TIMING DETAILS--ALONG AND SOUTH OF HIGHWAY 20
AND WEST OF INTERSTATE 35 REMAINDER OF THE MORNING AND THIS
AFTERNOON.  ALL OF FORECAST AREA FROM 900 PM TONIGHT TO 600 AM
SATURDAY MORNING.

METEOROLOGICAL COMMENTS--A THUNDERSTORM COMPLEX WILL MOVE ACROSS
SOUTHWEST IOWA.  STORMS WITHIN THIS SYSTEM WILL CONTINUE TO MAINTAIN
THEIR STRENGTH AS THEY MOVE INTO A MOIST AND UNSTABLE AIRMASS IN
PLACE OVER SOUTHWEST IOWA. BY THIS AFTERNOON...A WARM FRONT WILL BE
MOVING NORTH ACROSS THE STATE.  WARMER AIR AND AN INCREASE IN
MOISTURE WILL INCREASE INSTABILITY ACROSS THE FORECAST AREA.
ANOTHER COMPLEX OF THUNDERSTORMS IS EXPECTED TO DEVELOP ACROSS SOUTH
DAKOTA AND NEBRASKA OVERNIGHT AND MOVE EAST INTO IOWA.  WITH
MODERATE INSTABILITY IN PLACE...A FEW STORMS OVERNIGHT MAY PRODUCE
HAIL UP TO ONE AND A HALF INCHES IN DIAMETER AS WELL AS WIND GUSTS
APPROACHING 65 MPH.  A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL
300 PM THIS AFTERNOON.

PRECAUTION--SPOTTER ACTIVATION WILL BE NEEDED FOR THE REMAINDER OF
THE MORNING AND THIS AFTERNOON SOUTH OF HIGHWAY 20 AND WEST OF
INTERSTATE 35. ACTIVATION MAY ONCE AGAIN BE NEEDED BY THIS EVENING
AND INTO THE OVERNIGHT.  CONTINUE TO MONITOR THE SITUATION AS
CONDITIONS MAY CHANGE AS THIS SYSTEM EVOLVES.

TC

Special weather statement, Jul 2, 11:10 AM CDT, 4 hours 19 minutes before

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-031100-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
1110 AM CDT FRI JUL 2 1999

HAZARD--SCATTERED THUNDERSTORMS WITH A FEW SEVERE THUNDERSTORMS
CAPABLE OF PRODUCING UP TO TWO INCH HAIL AND WIND GUSTS TO 65 MPH.
SOME OF THE SEVERE THUNDERSTORMS COULD PRODUCE A TORNADO.

AREA OF CONCERN AND TIMING DETAILS--ALONG AND SOUTH OF HIGHWAY 20
AND WEST OF INTERSTATE 35 REMAINDER OF THE MORNING AND THIS
AFTERNOON.  ALL OF FORECAST AREA FROM 900 PM TONIGHT TO 600 AM
SATURDAY MORNING.

METEOROLOGICAL COMMENTS--A THUNDERSTORM COMPLEX WILL MOVE ACROSS
SOUTHWEST IOWA.  STORMS WITHIN THIS SYSTEM WILL CONTINUE TO MAINTAIN
THEIR STRENGTH AS THEY MOVE INTO A MOIST AND UNSTABLE AIRMASS IN
PLACE OVER SOUTHWEST IOWA. BY THIS AFTERNOON...A WARM FRONT WILL BE
MOVING NORTH ACROSS THE STATE.  WARMER AIR AND AN INCREASE IN
MOISTURE WILL INCREASE INSTABILITY ACROSS THE FORECAST AREA.
ANOTHER COMPLEX OF THUNDERSTORMS IS EXPECTED TO DEVELOP ACROSS SOUTH
DAKOTA AND NEBRASKA OVERNIGHT AND MOVE EAST INTO IOWA.  WITH
MODERATE INSTABILITY IN PLACE...A FEW STORMS OVERNIGHT MAY PRODUCE
HAIL UP TO ONE AND A HALF INCHES IN DIAMETER AS WELL AS WIND GUSTS
APPROACHING 65 MPH.  A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL
300 PM THIS AFTERNOON.

PRECAUTION--SPOTTER ACTIVATION WILL BE NEEDED FOR THE REMAINDER OF
THE MORNING AND THIS AFTERNOON SOUTH OF HIGHWAY 20 AND WEST OF
INTERSTATE 35. ACTIVATION MAY ONCE AGAIN BE NEEDED BY THIS EVENING
AND INTO THE OVERNIGHT.  CONTINUE TO MONITOR THE SITUATION AS
CONDITIONS MAY CHANGE AS THIS SYSTEM EVOLVES.

TC

Local storm report, Jul 2, 3:27 PM CDT, 2 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
327 PM CDT FRI JUL 02 1999

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

1119 AM    3 NW DOW CITY             IA    60+ MPH TSTM GUST
07/02/99   CRAWFORD                        TREE LIMBS DOWN

1132 AM    DOW CITY                  IA    1.75 INCH HAIL
07/02/99   CRAWFORD

1132 AM    DOW CITY                  IA    60+ MPH TSTM GUST
07/02/99   CRAWFORD                        TREE DAMAGE

1132 AM    DENISON MUNI ARPT         IA    66 MPH TSTM GUST
07/02/99   CRAWFORD

1137 AM    DENISON                   IA    60+ MPH TSTM GUST
07/02/99   CRAWFORD                        TREE DAMAGE

1137 AM    DENISON                   IA    1 INCH HAIL
07/02/99   CRAWFORD

1204 PM    6 SW CARROLL              IA    1.75 INCH HAIL
07/02/99   CARROLL

1215 PM    10 SW CARROLL             IA    1.75 INCH HAIL
07/02/99   CARROLL

1225 PM    TEMPLETON                 IA    1.25 INCH HAIL
07/02/99   CARROLL

1230 PM    5 NE AUDUBON              IA    1 INCH HAIL
07/02/99   AUDUBON

1251 PM    3 NW BAYARD               IA    1.75 INCH HAIL
07/02/99   GUTHRIE

1256 PM    3 NW BAYARD               IA    1.75 INCH HAIL
07/02/99   GUTHRIE

1256 PM    3 NW BAYARD               IA    2 INCH HAIL
07/02/99   GUTHRIE

0128 PM    JAMAICA                   IA    2 INCH HAIL
07/02/99   GUTHRIE

0138 PM    8 W PERRY                 IA    1.75 INCH HAIL
07/02/99   DALLAS

0148 PM    7 W PERRY                 IA    1 INCH HAIL
07/02/99   DALLAS                          CLOUD ROTATION

0202 PM    10 N AUDUBON              IA    1 INCH HAIL
07/02/99   AUDUBON

0218 PM    5 NW AUDUBON              IA    1 INCH HAIL
07/02/99   AUDUBON

0220 PM    AUDUBON                   IA    1.75 INCH HAIL
07/02/99   AUDUBON

0224 PM    2 E HAMLIN                IA    2 INCH HAIL
07/02/99   AUDUBON

0234 PM    13 W GUTHRIE CENTER       IA    1.75 INCH HAIL
07/02/99   GUTHRIE

0235 PM    2 E HAMLIN                IA    1.75 INCH HAIL
07/02/99   AUDUBON

0242 PM    10 SW GUTHRIE CENTER      IA    2.75 INCH HAIL
07/02/99   GUTHRIE

0247 PM    3 N ADvAIR                 IA    2.75 INCH HAIL
07/02/99   ADAIR

Local storm report, Jul 2, 3:27 PM CDT, 2 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
327 PM CDT FRI JUL 02 1999

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

1119 AM    3 NW DOW CITY             IA    60+ MPH TSTM GUST
07/02/99   CRAWFORD                        TREE LIMBS DOWN

1132 AM    DOW CITY                  IA    1.75 INCH HAIL
07/02/99   CRAWFORD

1132 AM    DOW CITY                  IA    60+ MPH TSTM GUST
07/02/99   CRAWFORD                        TREE DAMAGE

1132 AM    DENISON MUNI ARPT         IA    66 MPH TSTM GUST
07/02/99   CRAWFORD

1137 AM    DENISON                   IA    60+ MPH TSTM GUST
07/02/99   CRAWFORD                        TREE DAMAGE

1137 AM    DENISON                   IA    1 INCH HAIL
07/02/99   CRAWFORD

1204 PM    6 SW CARROLL              IA    1.75 INCH HAIL
07/02/99   CARROLL

1215 PM    10 SW CARROLL             IA    1.75 INCH HAIL
07/02/99   CARROLL

1225 PM    TEMPLETON                 IA    1.25 INCH HAIL
07/02/99   CARROLL

1230 PM    5 NE AUDUBON              IA    1 INCH HAIL
07/02/99   AUDUBON

1251 PM    3 NW BAYARD               IA    1.75 INCH HAIL
07/02/99   GUTHRIE

1256 PM    3 NW BAYARD               IA    1.75 INCH HAIL
07/02/99   GUTHRIE

1256 PM    3 NW BAYARD               IA    2 INCH HAIL
07/02/99   GUTHRIE

0128 PM    JAMAICA                   IA    2 INCH HAIL
07/02/99   GUTHRIE

0138 PM    8 W PERRY                 IA    1.75 INCH HAIL
07/02/99   DALLAS

0148 PM    7 W PERRY                 IA    1 INCH HAIL
07/02/99   DALLAS                          CLOUD ROTATION

0202 PM    10 N AUDUBON              IA    1 INCH HAIL
07/02/99   AUDUBON

0218 PM    5 NW AUDUBON              IA    1 INCH HAIL
07/02/99   AUDUBON

0220 PM    AUDUBON                   IA    1.75 INCH HAIL
07/02/99   AUDUBON

0224 PM    2 E HAMLIN                IA    2 INCH HAIL
07/02/99   AUDUBON

0234 PM    13 W GUTHRIE CENTER       IA    1.75 INCH HAIL
07/02/99   GUTHRIE

0235 PM    2 E HAMLIN                IA    1.75 INCH HAIL
07/02/99   AUDUBON

0242 PM    10 SW GUTHRIE CENTER      IA    2.75 INCH HAIL
07/02/99   GUTHRIE

0247 PM    3 N ADvAIR                 IA    2.75 INCH HAIL
07/02/99   ADAIR

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 2, 10:47 AM CDT	Tornado Warning	DMX	Crawford	48 min
Jul 2, 11:29 AM CDT	Tornado Warning	DMX	Crawford	36 min
Jul 2, 12:01 PM CDT	Severe Thunderstorm Warning	DMX	Carroll	34 min
Jul 2, 12:22 PM CDT	Severe Thunderstorm Warning	DMX	Carroll	33 min
Jul 2, 12:37 PM CDT	Severe Thunderstorm Warning	DMX	Audubon, Guthrie	48 min
Jul 2, 12:45 PM CDT	Severe Thunderstorm Warning	DMX	Greene	50 min
Jul 2, 1:22 PM CDT	Severe Thunderstorm Warning	DMX	Dallas	48 min
Jul 2, 1:42 PM CDT	Severe Thunderstorm Warning	DMX	Audubon	48 min
Jul 2, 2:07 PM CDT	Tornado Warning	DMX	Audubon	33 min
Jul 2, 2:28 PM CDT	Severe Thunderstorm Warning	DMX	Guthrie	47 min
Jul 2, 3:00 PM CDT	Severe Thunderstorm Warning	DMX	Adair	65 min
Jul 2, 3:10 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun	35 min
Jul 2, 3:16 PM CDT	Severe Thunderstorm Warning	DMX	Guthrie	19 min
Jul 2, 3:23 PM CDT	Severe Thunderstorm Warning	DMX	Webster	47 min
Jul 2, 4:05 PM CDT	Severe Thunderstorm Warning	DMX	Madison	35 min
Jul 2, 4:43 PM CDT	Severe Thunderstorm Warning	DMX	Webster	32 min
Jul 2, 5:12 PM CDT	Severe Thunderstorm Warning	DMX	Hamilton	33 min
Jul 2, 5:21 PM CDT	Severe Thunderstorm Warning	DMX	Boone	34 min
Jul 2, 5:24 PM CDT	Severe Thunderstorm Warning	DMX	Webster	31 min
Jul 2, 5:38 PM CDT	Severe Thunderstorm Warning	DMX	Boone	47 min
Jul 2, 5:46 PM CDT	Severe Thunderstorm Warning	DMX	Hamilton	34 min
Jul 2, 5:57 PM CDT	Severe Thunderstorm Warning	DMX	Story	48 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1999 Every severe thunderstorm warning in 1999

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.