Alert archive / Iowa / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 179, NWS Sioux Falls, SD

July 30, 1999Buena Vista County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 30, 1999, 7:35 PM CDT for Buena Vista County, Iowa. It was in force for 20 min. 1 report 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 30, 1999, 7:35 PM CDT (00:35 UTC)
Expired: Jul 30, 1999, 7:55 PM CDT
In force: 20 min
Issued by: NWS Sioux Falls, SD
Area: Whole counties

County Buena Vista County, IA

What was reported inside it

Time	Report	Where	Remark
Jul 30, 7:37 PM CDT	Hail 0.88	Marathon, 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, 0.6 hours before the alert went out and 266 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: 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.

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 Jul 30, 3:25 PM CDT, 4 hours 10 minutes earlier.

Area forecast discussion, Jul 30, 3:25 PM CDT, 4 hours 10 minutes before

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In the hours before

Local storm report, Jul 30, 3:26 PM CDT, 4 hours 9 minutes before

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Special weather statement, Jul 30, 5:53 PM CDT, 1 hour 42 minutes before

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Nearby

Severe Thunderstorm Warnings in Iowa, 1999 Every 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.