Alert archive / Iowa / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 115, NWS Des Moines, IA

July 31, 1999Story County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 31, 1999, 12:26 AM CDT for Story County, Iowa. It was in force for 34 min. 7 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 31, 1999, 12:26 AM CDT (05:26 UTC)
Expired
Jul 31, 1999, 1:00 AM CDT
In force
34 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Story County, IA

What was reported inside it

TimeReportWhereRemark
Jul 31, 12:30 AM CDTThunderstorm Wind 52Ames, IA
Jul 31, 12:30 AM CDTThunderstorm Wind 65Kelley, IA
Jul 31, 12:30 AM CDTThunderstorm Wind 50Ames, IA
Jul 31, 12:35 AM CDTThunderstorm Wind 52Colo, IA
Jul 31, 12:35 AM CDTThunderstorm Wind 52Ames, IA
Jul 31, 12:35 AM CDTThunderstorm Wind 52Cambridge, IA
Jul 31, 12:40 AM CDTThunderstorm Wind 57Ames Arpt, 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 nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 5.4 hours before the alert went out and 313 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, Minneapolis, MN at 00:00Z on 1999-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 101 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 1999-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -273 square meters per square second.19395878Sfc1 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
101 J/kg
Mixed-layer CIN
-246 J/kg
Mixed-layer LCL
1129 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
-273 m²/s²
0-3 km storm-relative helicity
-316 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 7:16 PM CDTSevere Thunderstorm WarningDMXWorth49 min
Jul 31, 12:33 AM CDTSevere Thunderstorm WarningDMXPolk32 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1999Every 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.