Alert archive / Wisconsin / Tornado Warnings in 1999

Tornado Warning 4, NWS Green Bay, WI

August 12, 1999Winnebago County, Wisconsin

NWS Green Bay, WI issued this tornado warning at Aug 12, 1999, 11:24 PM CDT for Winnebago County, Wisconsin. It was in force for 31 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
Aug 12, 1999, 11:24 PM CDT (04:24 UTC)
Expired
Aug 12, 1999, 11:55 PM CDT
In force
31 min
Issued by
NWS Green Bay, WI
Area
Whole counties

County Winnebago County, WI

The radar

The Green Bay radar (KGRB), 64 km from the middle of the area, began a volume at 04:28 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.

What was reported inside it

TimeReportWhereRemark
Aug 12, 11:37 PM CDTHail 1.75Winchester, WI

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

Green Bay/Straub, WI (KGRB), launched 00:00Z, 4.4 hours before the alert went out and 63 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, Green Bay/Straub, WI at 00:00Z on 1999-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 59 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, Green Bay/Straub, WI at 00:00Z on 1999-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 322 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
59 J/kg
Mixed-layer CIN
-176 J/kg
Mixed-layer LCL
545 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
322 m²/s²
0-3 km storm-relative helicity
414 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KGRB 130426 RRA
TORGRB
WIC139-130455-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE GREEN BAY WI
1124 PM CDT THU AUG 12 1999

THE NATIONAL WEATHER SERVICE IN GREEN BAY HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHERN WINNEBAGO COUNTY IN EAST CENTRAL WISCONSIN

* UNTIL 1155 PM CDT

* AT 1120 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR DETECTED A
  THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 20 MILES NORTHWEST OF
  OSHKOSH.  THE STXORM WAS MOVING EAST AT 35 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  WINCHESTER BY 1135 PM
  ALLENVILLE BY 1135 PM
  NEENAH BY 1145 PM CDT

GO TO THE BASEMENT OR A SMALL INTERIOR ROOM ON THE LOWEST FLOOR.

PLH/DK

The office that day

Everything else NWS Green Bay, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 12, 11:08 PM CDTSevere Thunderstorm WarningGRBWaushara, Winnebago32 min
Aug 12, 11:53 PM CDTSevere Thunderstorm WarningGRBCalumet, Outagamie47 min
Aug 12, 11:59 PM CDTSevere Thunderstorm WarningGRBWinnebago31 min
Aug 13, 12:20 AM CDTSevere Thunderstorm WarningGRBBrown45 min
Aug 13, 1:26 AM CDTSevere Thunderstorm WarningGRBLanglade34 min

Nearby

Tornado Warnings in Wisconsin, 1999Every tornado warning in 1999Tornadoes 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; radar from the NEXRAD Level II archive.