Alert archive / Iowa / Tornado Warnings in 1999

Tornado Warning 9, NWS Des Moines, IA

April 8, 1999Union County, Iowa

NWS Des Moines, IA issued this tornado warning at Apr 8, 1999, 3:52 PM CDT for Union County, Iowa. It was in force for 33 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Apr 8, 1999, 3:52 PM CDT (20:52 UTC)
Expired: Apr 8, 1999, 4:25 PM CDT
In force: 33 min
Issued by: NWS Des Moines, IA
Area: Whole counties

County Union County, IA

The radar

The Des Moines radar (KDMX), 89 km from the middle of the area, began a volume at 20:51 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.

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 8, 1:00 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Topeka, KS (KTOP), launched 12:00Z, 8.9 hours before the alert went out and 255 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: 1142 J/kg
Mixed-layer CIN: -382 J/kg
Mixed-layer LCL: 1189 m above ground
0-6 km bulk shear: 72 kt
0-1 km storm-relative helicity: 446 m²/s²
0-3 km storm-relative helicity: 629 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 082052 RRA
TORDSM
IAC175-082125-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
352 PM CDT THU APR 8 1999

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  UNION COUNTY IN SOUTH CENTRAL IOWA

* UNTIL 425 PM CDT

* AT 351 PM CDT... LOCAL LAW ENFORCEMENT REPORTED A TORNADO 50 MILES
  SOUTHWEST OF DES MOINES OR 4 MILES EAST NORTHEAST OF CRESTON...
  MOVING NORTH NORTHEAST AT 50 MPH.

THE TORNADO IS EXPECTED TO REMAIN OVER RURAL AREAS.


A TORNADO IS ON THE GROUND! GO TO THE BASEMENT! IF A BASEMENT IS
NOT AVAILABLE...GO TO A SMALL INTERIOR ROOM ON THE LOWEST FLOOR!

GGF

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 8, 7:36 AM CDT	Severe Thunderstorm Warning	DMX	Adair	34 min
Apr 8, 7:47 AM CDT	Severe Thunderstorm Warning	DMX	Madison	33 min
Apr 8, 8:37 AM CDT	Severe Thunderstorm Warning	DMX	Warren	33 min
Apr 8, 11:43 AM CDT	Severe Thunderstorm Warning	DMX	Adair	32 min
Apr 8, 12:02 PM CDT	Severe Thunderstorm Warning	DMX	Boone	33 min
Apr 8, 12:05 PM CDT	Severe Thunderstorm Warning	DMX	Greene	35 min
Apr 8, 12:39 PM CDT	Severe Thunderstorm Warning	DMX	Dallas	36 min
Apr 8, 12:48 PM CDT	Severe Thunderstorm Warning	DMX	Marshall	47 min
Apr 8, 1:16 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Story	34 min
Apr 8, 1:48 PM CDT	Severe Thunderstorm Warning	DMX	Story	32 min
Apr 8, 2:45 PM CDT	Tornado Warning	DMX	Adams, Taylor	50 min
Apr 8, 2:57 PM CDT	Severe Thunderstorm Warning	DMX	Grundy, Hardin	33 min
Apr 8, 2:59 PM CDT	Tornado Warning	DMX	Cass	31 min
Apr 8, 3:18 PM CDT	Tornado Warning	DMX	Adair	42 min
Apr 8, 3:32 PM CDT	Severe Thunderstorm Warning	DMX	Audubon, Cass	48 min
Apr 8, 3:46 PM CDT	Tornado Warning	DMX	Guthrie	49 min
Apr 8, 3:55 PM CDT	Tornado Warning	DMX	Madison	35 min
Apr 8, 4:20 PM CDT	Tornado Warning	DMX	Dallas	50 min
Apr 8, 4:44 PM CDT	Tornado Warning	DMX	Wayne	36 min
Apr 8, 4:47 PM CDT	Tornado Warning	DMX	Polk	48 min
Apr 8, 4:56 PM CDT	Tornado Warning	DMX	Lucas, Warren	49 min
Apr 8, 5:07 PM CDT	Tornado Warning	DMX	Marion	48 min
Apr 8, 5:15 PM CDT	Tornado Warning	DMX	Dallas	35 min
Apr 8, 5:37 PM CDT	Tornado Warning	DMX	Marion, Monroe	33 min
Apr 8, 5:37 PM CDT	Tornado Warning	DMX	Jasper	33 min
Apr 8, 5:49 PM CDT	Tornado Warning	DMX	Appanoose	31 min
Apr 8, 5:51 PM CDT	Tornado Warning	DMX	Polk	49 min
Apr 8, 6:05 PM CDT	Tornado Warning	DMX	Davis	35 min
Apr 8, 6:06 PM CDT	Tornado Warning	DMX	Mahaska	34 min
Apr 8, 6:16 PM CDT	Tornado Warning	DMX	Wapello	34 min

Nearby

Tornado Warnings in Iowa, 1999 Every tornado warning in 1999 Tornadoes 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.