Alert archive / Iowa / Tornado Watches in 1999

Tornado Watch 405

June 6, 199944 counties in Iowa; 8 counties in Missouri; Nemaha County, Richardson County, Nebraska

The Storm Prediction Center issued this tornado watch at Jun 6, 1999, 2:00 PM CDT for 44 counties in Iowa; 8 counties in Missouri; Nemaha County, Richardson County, Nebraska. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jun 6, 1999, 2:00 PM CDT (19:00 UTC)
Expired
Jun 6, 1999, 8:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 54 counties

Adair County, IA, Adams County, IA, Audubon County, IA, Boone County, IA, Buena Vista County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cerro Gordo County, IA, Cherokee County, IA, Clarke County, IA, Clay County, IA, Crawford County, IA, Dallas County, IA, Decatur County, IA, Franklin County, IA, Fremont County, IA, Greene County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Harrison County, IA, Humboldt County, IA, Ida County, IA, Kossuth County, IA, Lucas County, IA, Madison County, IA, Mills County, IA, Montgomery County, IA, Page County, IA, Palo Alto County, IA, Pocahontas County, IA, Polk County, IA, Pottawattamie County, IA, Ringgold County, IA, Sac County, IA, Shelby County, IA, Story County, IA, Taylor County, IA, Union County, IA, Warren County, IA, Webster County, IA, Wright County, IA, Atchison County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Holt County, MO, Mercer County, MO, Nodaway County, MO, Worth County, MO, Nemaha County, NE, Richardson County, NE

The radar

The Des Moines radar (KDMX), 101 km from the middle of the area, began a volume at 19:01 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.

Warnings issued inside it

22 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jun 6, 2:32 PM CDTSevere Thunderstorm WarningDMXAudubon33 min
Jun 6, 2:46 PM CDTSevere Thunderstorm WarningOAXPottawattamie, Shelby49 min
Jun 6, 3:09 PM CDTSevere Thunderstorm WarningDMXHumboldt, Kossuth36 min
Jun 6, 3:19 PM CDTSevere Thunderstorm WarningDMXGreene, Webster31 min
Jun 6, 3:36 PM CDTSevere Thunderstorm WarningDMXKossuth34 min
Jun 6, 3:39 PM CDTTornado WarningDMXWebster36 min
Jun 6, 3:58 PM CDTSevere Thunderstorm WarningDMXHancock, Wright32 min
Jun 6, 3:58 PM CDTSevere Thunderstorm WarningDMXHamilton32 min
Jun 6, 4:13 PM CDTTornado WarningDMXWright32 min
Jun 6, 4:30 PM CDTSevere Thunderstorm WarningDMXCerro Gordo, Franklin30 min
Jun 6, 4:33 PM CDTTornado WarningDMXFranklin32 min
Jun 6, 4:46 PM CDTSevere Thunderstorm WarningOAXFremont, Page49 min
Jun 6, 5:26 PM CDTSevere Thunderstorm WarningOAXNemaha, Richardson49 min
Jun 6, 5:45 PM CDTSevere Thunderstorm WarningDMXAudubon35 min
Jun 6, 5:45 PM CDTSevere Thunderstorm WarningOAXMontgomery50 min
Jun 6, 5:52 PM CDTSevere Thunderstorm WarningDMXCalhoun33 min
Jun 6, 6:16 PM CDTSevere Thunderstorm WarningDMXGreene34 min
Jun 6, 6:29 PM CDTTornado WarningDMXAdair, Cass31 min
Jun 6, 6:36 PM CDTTornado WarningDMXBoone, Greene, Webster49 min
Jun 6, 6:42 PM CDTSevere Thunderstorm WarningDMXHumboldt, Wright33 min
Jun 6, 7:08 PM CDTTornado WarningDMXHamilton32 min
Jun 6, 7:31 PM CDTSevere Thunderstorm WarningDMXCerro Gordo34 min

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 7.0 hours before the alert went out and 128 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-pSkew-T log-p diagram, Omaha, NE at 12:00Z on 1999-06-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1572 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 12:00Z on 1999-06-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 103 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
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
1572 J/kg
Mixed-layer CIN
-73 J/kg
Mixed-layer LCL
922 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
103 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
0.8
Supercell composite
5.5

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.

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 5, 9:00 PM CDTTornado WatchSPCClay, Dickinson, Emmet, Lyon, O'Brien, Osceola and 3 more5 hr
Jun 5, 9:45 PM CDTTornado WatchSPCAllamakee, Bremer, Butler, Cerro Gordo, Chickasaw, Clayton and 11 more4 hr
Jun 6, 12:45 PM CDTSevere Thunderstorm WatchSPCAllamakee, Benton, Black Hawk, Bremer, Buchanan, Butler and 21 more5 hr
Jun 6, 6:00 PM CDTTornado WatchSPCAdair, Adams, Allamakee, Appanoose, Audubon, Benton and 55 more6 hr
Jun 6, 5:45 PM CDTSevere Thunderstorm WatchSPCAndrew, Buchanan, Clinton, DeKalb, Platte4 hr

Nearby

Tornado Watches in Iowa, 1999Tornado Watches in Missouri, 1999Tornado Watches in Nebraska, 1999Every tornado watch 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.