Alert archive / Iowa / Tornado Watches in 1999

Tornado Watch 134

April 8, 199939 counties in Iowa; Doniphan County, Kansas; 28 counties in Missouri

The Storm Prediction Center issued this tornado watch at Apr 8, 1999, 1:00 PM CDT for 39 counties in Iowa; Doniphan County, Kansas; 28 counties in Missouri. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 8, 1999, 1:00 PM CDT (18:00 UTC)
Expired
Apr 8, 1999, 7:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 68 counties

Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Boone County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Clarke County, IA, Crawford County, IA, Dallas County, IA, Decatur County, IA, Fremont County, IA, Greene County, IA, Guthrie County, IA, Hamilton County, IA, Harrison County, IA, Ida County, IA, Jasper County, IA, Lucas County, IA, Madison County, IA, Marion County, IA, Mills County, IA, Monona County, IA, Monroe County, IA, Montgomery County, IA, Page 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, Wayne County, IA, Webster County, IA, Woodbury County, IA, Doniphan County, KS, Adair County, MO, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Caldwell County, MO, Carroll County, MO, Chariton County, MO, Clay County, MO, Clinton County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Holt County, MO, Howard County, MO, Linn County, MO, Livingston County, MO, Macon County, MO, Mercer County, MO, Nodaway County, MO, Platte County, MO, Putnam County, MO, Randolph County, MO, Ray County, MO, Saline County, MO, Sullivan County, MO, Worth County, MO

The radar

The Des Moines radar (KDMX), 72 km from the middle of the area, began a volume at 18:01 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

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

IssuedProductOfficeCountiesLasted
Apr 8, 1:16 PM CDTSevere Thunderstorm WarningDMXBoone, Story34 min
Apr 8, 1:48 PM CDTSevere Thunderstorm WarningDMXStory32 min
Apr 8, 1:52 PM CDTSevere Thunderstorm WarningEAXDoniphan53 min
Apr 8, 1:58 PM CDTTornado WarningOAXPottawattamie32 min
Apr 8, 2:05 PM CDTTornado WarningOAXMonona50 min
Apr 8, 2:10 PM CDTSevere Thunderstorm WarningOAXHarrison50 min
Apr 8, 2:10 PM CDTSevere Thunderstorm WarningEAXAtchison, Nodaway50 min
Apr 8, 2:12 PM CDTTornado WarningOAXFremont, Montgomery, Page33 min
Apr 8, 2:23 PM CDTTornado WarningOAXHarrison32 min
Apr 8, 2:31 PM CDTTornado WarningEAXNodaway29 min
Apr 8, 2:40 PM CDTTornado WarningOAXMontgomery, Page30 min
Apr 8, 2:42 PM CDTTornado WarningOAXPottawattamie33 min
Apr 8, 2:45 PM CDTTornado WarningDMXAdams, Taylor50 min
Apr 8, 2:53 PM CDTTornado WarningOAXHarrison, Monona32 min
Apr 8, 2:59 PM CDTTornado WarningDMXCass31 min
Apr 8, 3:18 PM CDTTornado WarningDMXAdair42 min
Apr 8, 3:21 PM CDTSevere Thunderstorm WarningOAXShelby29 min
Apr 8, 3:26 PM CDTSevere Thunderstorm WarningOAXHarrison, Monona34 min
Apr 8, 3:32 PM CDTSevere Thunderstorm WarningDMXAudubon, Cass48 min
Apr 8, 3:37 PM CDTSevere Thunderstorm WarningEAXLafayette, Ray38 min
Apr 8, 3:46 PM CDTTornado WarningDMXGuthrie49 min
Apr 8, 3:52 PM CDTTornado WarningDMXUnion33 min
Apr 8, 3:55 PM CDTTornado WarningDMXMadison35 min
Apr 8, 3:56 PM CDTSevere Thunderstorm WarningEAXCarroll34 min
Apr 8, 4:03 PM CDTTornado WarningEAXCarroll27 min
Apr 8, 4:20 PM CDTTornado WarningDMXDallas50 min
Apr 8, 4:20 PM CDTTornado WarningEAXChariton40 min
Apr 8, 4:32 PM CDTSevere Thunderstorm WarningEAXLinn, Livingston43 min
Apr 8, 4:44 PM CDTTornado WarningDMXWayne36 min
Apr 8, 4:47 PM CDTTornado WarningDMXPolk48 min
Apr 8, 4:54 PM CDTTornado WarningEAXLinn, Macon36 min
Apr 8, 4:56 PM CDTTornado WarningDMXLucas, Warren49 min
Apr 8, 5:07 PM CDTTornado WarningDMXMarion48 min
Apr 8, 5:15 PM CDTTornado WarningDMXDallas35 min
Apr 8, 5:28 PM CDTTornado WarningEAXMacon32 min
Apr 8, 5:37 PM CDTTornado WarningDMXMarion, Monroe33 min
Apr 8, 5:37 PM CDTTornado WarningDMXJasper33 min
Apr 8, 5:47 PM CDTSevere Thunderstorm WarningEAXCooper, Howard43 min
Apr 8, 5:49 PM CDTTornado WarningDMXAppanoose31 min
Apr 8, 5:51 PM CDTTornado WarningDMXPolk49 min

The nearest sounding before it

Topeka, KS (KTOP), launched 12:00Z, 6.0 hours before the alert went out and 273 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, Topeka, KS at 12:00Z on 1999-04-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1142 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, Topeka, KS at 12:00Z on 1999-04-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 446 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
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

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
Apr 8, 6:30 AM CDTSevere Thunderstorm WatchSPCFremont, Mills, Page6 hr
Apr 8, 11:45 AM CDTTornado WatchSPCFremont, Mills, Page5 hr
Apr 8, 5:15 PM CDTTornado WatchSPCAppanoose, Benton, Cedar, Clinton, Davis, Des Moines and 26 more4 hr
Apr 8, 5:15 PM CDTTornado WatchSPCAudrain, Benton, Boone, Callaway, Camden, Chariton and 24 more4 hr
Apr 8, 6:15 PM CDTTornado WatchSPCBarry, Carter, Christian, Crawford, Dallas, Dent and 19 more4 hr

Nearby

Tornado Watches in Iowa, 1999Tornado Watches in Missouri, 1999Tornado Watches in Kansas, 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.