Alert archive / South Dakota / Severe Thunderstorm Warnings in 2004

Severe Thunderstorm Warning 51, NWS Sioux Falls, SD

April 18, 2004Union County, South Dakota; Woodbury County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Apr 18, 2004, 6:55 PM CDT for Union County, South Dakota; Woodbury County, Iowa. It was in force for 50 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Apr 18, 2004, 6:55 PM CDT (23:55 UTC)
Expired: Apr 18, 2004, 7:45 PM CDT
In force: 50 min
Issued by: NWS Sioux Falls, SD
Area: Counties, with a storm outline in the text

Counties Woodbury County, IA, Union County, SD

The radar

The Sioux Falls radar (KFSD), 126 km from the middle of the area, began a volume at 23:58 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
Apr 18, 6:55 PM CDT	TSTM WND GST 60	North Sioux City, SD
Apr 18, 7:10 PM CDT	HAIL 0.75	Sioux City, IA	NORTH SIDE OF SIOUX CITY.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched one storm report to this severe thunderstorm warning; the first came 0 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

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

Issued	Product	Office	Lasted
Apr 18, 2:20 PM CDT	Severe Thunderstorm Watch	SPC	6 hr
Apr 18, 4:40 PM CDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 11.9 hours before the alert went out and 129 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: 256 J/kg
Mixed-layer CIN: -464 J/kg
Mixed-layer LCL: 995 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 365 m²/s²
0-3 km storm-relative helicity: 406 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

762 
WUUS53 KFSD 182355
SVRFSD
IAC193-SDC127-190045-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
654 PM CDT SUN APR 18 2004

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WESTERN WOODBURY COUNTY IN NORTHWEST IOWA
  EXTREME SOUTHEAST UNION COUNTY IN SOUTHEAST SOUTH DAKOTA

* UNTIL 745 PM CDT

* AT 648 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING NICKEL SIZE
  HAIL...AND DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THESE STORMS
  WERE LOCATED ALONG A LINE EXTENDING FROM 8 MILES NORTHEAST OF NORTH
  SIOUX CITY TO 13 MILES SOUTHWEST OF NORTH SIOUX CITY...OR FROM 9
  MILES NORTH OF SIOUX CITY TO 12 MILES SOUTH OF PONCA...MOVING EAST
  AT 25 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  SIOUX CITY AROUND 705 PM CDT
  SALIX...LAWTON AROUND 735 PM CDT

THIS STORM WILL PRODUCE LARGE HAIL AND DAMAGING WIND. GO INSIDE A
STURDY BUILDING AND STAY AWAY FROM WINDOWS.

LAT...LON 4261 9658 4253 9656 4247 9639 4225 9632
          4227 9614 4255 9608 4256 9650

$$

BOUSTEAD

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 Sioux Falls, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 18, 3:35 PM CDT, 3 hours 20 minutes earlier.

Area forecast discussion, Apr 18, 3:35 PM CDT, 3 hours 20 minutes before

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
335 PM CDT SUN APR 18 2004

.DISCUSSION...

ONGOING WX AND WL KEEP THIS SHORT. MAIN PBLM TONIGHT WL BE SVR
STORMS AND WND THIS EVE. UPPER LOW LIFTING NEWD ACRS SD AND
INTERACTING ALONG FNT TO TRIGGER TRW. ALSO SCT TRW BEHIND FNT ...BUT
THESE WL LIKELY DISSPIATE TOWARDS SS WITH MAIN FOCUS OF TRW SHIFTING
EWD ALONG FNT. WL CONT WIND ADVY FOR PARTS OF SW MN...NW IA AND NE
NEB THIS EVE.

ANOTHER S/W WILL MOVE ACRS CWA TUE AND TUES NIGHT WITH UPPER WAVE
HAVING MOR NEG TILT. SO WUD EXPECT A BETTER CHC OF RAIN WITH THIS
SYS AND HAVE GONE LIKELY FOR POPS ON TUES. TEMPS WL BE COOLER TUES
WITH CLOUDS AND PRECIP..WITH ABOVE NORM TEMPS ON MON...BUT STILL
MUCH COOLER THAN TODAY.

ANOTHER S/W ACRS CNTRL AND SRN PLAINS THU MAY CLIP SERN CWA WITH A
CHC OF RW-. DRY FRI INTO SUN WITH A WARMING TREND.
&&

.FSD...WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVY UNTIL 01Z ZONES 071
MN...WIND ADVY UNTIL 01Z ZONES 072-080-081-089-090.
IA...WIND ADVY UNTIL 01Z ZONES 001>003-012>014-020>022-031-032
NE...WIND ADVY UNTIL 01Z ZONES 013-014.

&&

Hazardous weather outlook, Apr 18, 10:55 AM CDT, 8 hours before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1055 AM CDT SUN APR 18 2004

SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098-
IAZ001>003-012>014-020>022-031-032-NEZ013-014-191200-
AURORA-BEADLE-BON HOMME-BROOKINGS-BRULE-BUENA VISTA IA-
CHARLES MIX-CHEROKEE IA-CLAY-CLAY IA-COTTONWOOD MN-DAKOTA NE-
DAVISON-DICKINSON IA-DIXON NE-DOUGLAS-GREGORY-HANSON-HUTCHINSON-
IDA IA-JACKSON MN-JERAULD-KINGSBURY-LAKE-LINCOLN-LINCOLN MN-
LYON IA-LYON MN-MCCOOK-MINER-MINNEHAHA-MOODY-MURRAY MN-NOBLES MN-
OBRIEN IA-OSCEOLA IA-PIPESTONE MN-PLYMOUTH IA-ROCK MN-SANBORN-
SIOUX IA-TURNER-UNION-WOODBURY IA-YANKTON-

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST SOUTH DAKOTA...
SOUTHWEST MINNESOTA...NORTHWEST IOWA...AND NORTHEAST NEBRASKA.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS...
LOW PRESSURE AND A COLD FRONT WILL MOVE ACROSS EASTERN SOUTH
DAKOTA AND INTO SOUTHWEST MINNESOTA TODAY. THE FRONT WILL THEN
MOVE SOUTHEAST ACROSS THE REST OF SOUTHWEST MINNESOTA...FAR
SOUTHEAST SOUTH DAKOTA...EXTREME NORTHEAST NEBRASKA...AND
NORTHWEST IOWA THIS EVENING. SCATTERED THUNDERSTORMS ARE EXPECTED
NEAR THE COLD FRONT. WHILE THERE IS JUST A CHANCE OF
THUNDERSTORMS...ANY STORMS THAT DEVELOP ALONG AND EAST OF THE
COLD FRONT COULD BECOME SEVERE WITH LARGE HAIL AND DAMAGING
WINDS. THE GREATEST RISK OF SEVERE STORMS WILL BE IN SOUTHWEST
MINNESOTA.

WIND AND FOG...
STRONG SOUTH TO SOUTHWEST WINDS WILL CONTINUE THIS AFTERNOON IN
NORTHWEST IOWA...SOUTHWEST MINNESOTA...THE SOUTHEAST CORNER OF
SOUTH DAKOTA...AND EXTREME NORTHEAST NEBRASKA. WIND ADVISORIES
HAVE BEEN ISSUED FOR THESE AREAS. SUSTAINED WINDS SHOULD
GENERALLY BE FROM 30 TO 40 MPH...BUT WINDS MAY GUST AS HIGH AS 50
TO 55 IN NORTHWEST IOWA AND SOUTHWEST MINNESOTA.

FIRE DANGER...
WARM TEMPERATURES...DRY VEGETATION...RELATIVE HUMIDITIES DROPPING
TO 30 TO 35 PERCENT...AND STRONG WINDS WILL COMBINE TO CAUSE A
VERY HIGH TO EXTREME FIRE DANGER. THE WINDS WILL BE STRONGEST IN
NORTHWEST IOWA AND PARTS OF SOUTHWEST MINNESOTA...WHERE SOUTHWEST
WINDS MAY GUST AS HIGH AS 50 TO 55 MPH.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE POSSIBLE AFTER 4 PM.

&&

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT
WWW.CRH.NOAA.GOV/FSD. THIS INCLUDES THE GRAPHICAL HAZARDOUS
WEATHER OUTLOOK.

In the hours before

Local storm report, Apr 18, 6:26 PM CDT, 29 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
626 PM CDT SUN APR 18 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0612 PM     TSTM WND DMG     3 N ROCK VALLEY         43.25N 96.30W
04/18/2004                   SIOUX              IA   TRAINED SPOTTER

            GRAVITY WAGONS TIPPED OVER AND SHED DESTROYED.

&&

CPJ

Local storm report, Apr 18, 6:27 PM CDT, 28 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
627 PM CDT SUN APR 18 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0622 PM     HAIL             SIOUX CENTER            43.08N 96.17W
04/18/2004  0.75 INCH        SIOUX              IA   TRAINED SPOTTER

&&

JRM

Local storm report, Apr 18, 6:29 PM CDT, 26 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
629 PM CDT SUN APR 18 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0629 PM     HAIL             2 NE MARSHALL           44.47N 95.76W
04/18/2004  1.00 INCH        LYON               MN   TRAINED SPOTTER

&&

JRM

Local storm report, Apr 18, 6:38 PM CDT, 17 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
638 PM CDT SUN APR 18 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0631 PM     HAIL             ALLEN                   42.41N 96.84W
04/18/2004  0.75 INCH        DIXON              NE   TRAINED SPOTTER

0635 PM     HAIL             4 W ALLEN               42.41N 96.92W
04/18/2004  0.88 INCH        DIXON              NE   TRAINED SPOTTER

&&

JRM

Local storm report, Apr 18, 6:41 PM CDT, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
641 PM CDT SUN APR 18 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0630 PM     HAIL             SIBLEY                  43.40N 95.74W
04/18/2004  1.00 INCH        OSCEOLA            IA   TRAINED SPOTTER

            AT SIBLEY AIRPORT.

&&

JRM

Local storm report, Apr 18, 6:55 PM CDT, 0 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
655 PM CDT SUN APR 18 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0650 PM     NON-TSTM WND GST 8 NW SIOUX CITY         42.58N 96.51W
04/18/2004  60 MPH           UNION              SD   TRAINED SPOTTER

&&

CPJ

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 17, 11:20 PM CDT	Severe Thunderstorm Warning	FSD	McCook, Minnehaha	40 min
Apr 17, 11:43 PM CDT	Severe Thunderstorm Warning	FSD	Lake, Moody	32 min
Apr 18, 12:00 AM CDT	Severe Thunderstorm Warning	FSD	Minnehaha	15 min
Apr 18, 12:08 AM CDT	Severe Thunderstorm Warning	FSD	Brookings	37 min
Apr 18, 12:15 AM CDT	Severe Thunderstorm Warning	FSD	Lake, Moody	45 min
Apr 18, 12:55 AM CDT	Severe Thunderstorm Warning	FSD	Moody	20 min
Apr 18, 3:49 PM CDT	Severe Thunderstorm Warning	FSD	Charles Mix	26 min
Apr 18, 3:52 PM CDT	Severe Thunderstorm Warning	FSD	Aurora	23 min
Apr 18, 3:56 PM CDT	Severe Thunderstorm Warning	FSD	Union	34 min
Apr 18, 3:59 PM CDT	Severe Thunderstorm Warning	FSD	Sanborn	46 min
Apr 18, 4:13 PM CDT	Severe Thunderstorm Warning	FSD	Bon Homme	32 min
Apr 18, 4:18 PM CDT	Severe Thunderstorm Warning	FSD	Hutchinson	42 min
Apr 18, 4:31 PM CDT	Severe Thunderstorm Warning	FSD	Miner	29 min
Apr 18, 4:38 PM CDT	Tornado Warning	FSD	Hutchinson	37 min
Apr 18, 4:45 PM CDT	Severe Thunderstorm Warning	FSD	Union	30 min
Apr 18, 4:46 PM CDT	Tornado Warning	FSD	Turner	29 min
Apr 18, 4:50 PM CDT	Severe Thunderstorm Warning	FSD	Kingsbury	25 min
Apr 18, 4:52 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln	38 min
Apr 18, 4:59 PM CDT	Severe Thunderstorm Warning	FSD	Brookings, Lake	46 min
Apr 18, 5:13 PM CDT	Tornado Warning	FSD	Union	47 min
Apr 18, 5:17 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Minnehaha	28 min
Apr 18, 5:23 PM CDT	Severe Thunderstorm Warning	FSD	Clay	37 min
Apr 18, 5:26 PM CDT	Severe Thunderstorm Warning	FSD	Brookings	34 min
Apr 18, 5:44 PM CDT	Severe Thunderstorm Warning	FSD	Union	46 min
Apr 18, 5:47 PM CDT	Flash Flood Warning	FSD	Union	58 min
Apr 18, 4:04 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth	26 min
Apr 18, 4:20 PM CDT	Severe Thunderstorm Warning	FSD	Sioux	25 min
Apr 18, 4:56 PM CDT	Severe Thunderstorm Warning	FSD	Lyon	49 min
Apr 18, 5:18 PM CDT	Severe Thunderstorm Warning	FSD	Sioux	42 min
Apr 18, 5:51 PM CDT	Severe Thunderstorm Warning	FSD	Lyon	24 min
Apr 18, 5:59 PM CDT	Severe Thunderstorm Warning	FSD	Sioux	61 min
Apr 18, 6:19 PM CDT	Severe Thunderstorm Warning	FSD	Osceola	56 min
Apr 18, 6:26 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth	64 min
Apr 18, 6:38 PM CDT	Severe Thunderstorm Warning	FSD	O'Brien	67 min
Apr 18, 6:59 PM CDT	Severe Thunderstorm Warning	FSD	Dickinson	46 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2004 Severe Thunderstorm Warnings in Iowa, 2004 Every severe thunderstorm warning in 2004

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.