Alert archive / Texas / Tornado Watches in 1999

Tornado Watch 303

May 20, 1999Harmon County, Jackson County, Oklahoma; 9 counties in Texas

The Storm Prediction Center issued this tornado watch at May 20, 1999, 9:00 PM CDT for Harmon County, Jackson County, Oklahoma; 9 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
May 20, 1999, 9:00 PM CDT (02:00 UTC)
Expired
May 21, 1999, 12:00 AM CDT
In force
3 hr
Issued by
the Storm Prediction Center

Counties Harmon County, OK, Jackson County, OK, Baylor County, TX, Childress County, TX, Cottle County, TX, Foard County, TX, Hall County, TX, Hardeman County, TX, King County, TX, Knox County, TX, Wilbarger County, TX

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 20, 9:00 PM CDTTornado WarningOUNHarmon, Jackson45 min
May 20, 9:44 PM CDTTornado WarningOUNJackson46 min
May 20, 9:50 PM CDTSevere Thunderstorm WarningOUNHarmon25 min
May 20, 11:16 PM CDTSevere Thunderstorm WarningLUBChildress44 min
May 20, 11:32 PM CDTSevere Thunderstorm WarningOUNHarmon43 min

The nearest sounding before it

Amarillo Airport, TX (KAMA), launched 00:00Z, 2.0 hours before the alert went out and 216 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, Amarillo Airport, TX at 00:00Z on 1999-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 40 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, Amarillo Airport, TX at 00:00Z on 1999-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 29 square meters per square second.193958Sfc1 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
40 J/kg
Mixed-layer CIN
-282 J/kg
Mixed-layer LCL
2737 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
29 m²/s²
0-3 km storm-relative helicity
216 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.

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 21, 6:15 PM CDTSevere Thunderstorm WatchSPCBrewster, Culberson, Hudspeth, Jeff Davis, Loving, Presidio and 1 more6 hr

Nearby

Tornado Watches in Texas, 1999Tornado Watches in Oklahoma, 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.