Alert archive / Texas / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 41, NWS Fort Worth, TX

February 6, 1999Grayson County, Texas

NWS Fort Worth, TX issued this severe thunderstorm warning at Feb 6, 1999, 6:46 PM CST for Grayson County, Texas. It was in force for 29 min. 3 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
Feb 6, 1999, 6:46 PM CST (00:46 UTC)
Expired
Feb 6, 1999, 7:15 PM CST
In force
29 min
Issued by
NWS Fort Worth, TX
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Grayson County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 131 km from the middle of the area, began a volume at 00:47 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
Feb 6, 6:50 PM CSTThunderstorm WindWhitesboro, TXThunderstorm winds blew signs down onto three trucks at the Whitesboro Autoplex.
Feb 6, 7:15 PM CSTHail 0.75Denison, TX
Feb 6, 7:25 PM CSTHail 0.88Denison, TX

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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Feb 6, 3:00 PM CSTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 0.8 hours before the alert went out and 189 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, Norman, OK at 00:00Z on 1999-02-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Norman, OK at 00:00Z on 1999-02-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -29 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
637 m above ground
0-6 km bulk shear
100 kt
0-1 km storm-relative helicity
-29 m²/s²
0-3 km storm-relative helicity
-50 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 Fort Worth, TX issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 6, 7:43 PM CSTSevere Thunderstorm WarningFWDCollin, Denton47 min
Feb 6, 8:09 PM CSTSevere Thunderstorm WarningFWDDallas, Rockwall51 min
Feb 6, 8:38 PM CSTSevere Thunderstorm WarningFWDCollin37 min
Feb 6, 8:48 PM CSTSevere Thunderstorm WarningFWDHunt57 min
Feb 6, 9:04 PM CSTSevere Thunderstorm WarningFWDDelta, Lamar56 min

Nearby

Severe Thunderstorm Warnings in Texas, 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; radar from the NEXRAD Level II archive.