Alert archive / Texas / Mesoscale Discussions in 2003

Mesoscale Discussion 106

February 21, 200323 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 21, 2003, 6:16 AM CST for 23 counties in Texas. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued
Feb 21, 2003, 6:16 AM CST (12:16 UTC)
Expired
Feb 21, 2003, 8:15 AM CST
In force
119 min
Issued by
the Storm Prediction Center
All 23 counties

Austin County, TX, Brazoria County, TX, Brazos County, TX, Burleson County, TX, Calhoun County, TX, Colorado County, TX, Fayette County, TX, Fort Bend County, TX, Grimes County, TX, Harris County, TX, Jackson County, TX, Lavaca County, TX, Liberty County, TX, Matagorda County, TX, Montgomery County, TX, Polk County, TX, Refugio County, TX, San Jacinto County, TX, Victoria County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Wharton County, TX

The radar

The Houston radar (KHGX), 103 km from the middle of the area, began a volume at 12:18 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.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 0.3 hours before the alert went out and 295 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, Lake Charles Mun, LA at 12:00Z on 2003-02-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 543 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, Lake Charles Mun, LA at 12:00Z on 2003-02-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 253 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
543 J/kg
Mixed-layer CIN
-114 J/kg
Mixed-layer LCL
433 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
253 m²/s²
0-3 km storm-relative helicity
274 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.2

Open this sounding in Storm Lab

The text

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

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 21, 1:43 AM CSTMesoscale DiscussionSPCChambers, Hardin, Jasper, Jefferson, Liberty, Newton and 1 more2 hr
Feb 21, 2:43 AM CSTMesoscale DiscussionSPCDimmit, Edwards, Frio, Kinney, La Salle, Maverick and 5 more3 hr
Feb 21, 3:53 AM CSTMesoscale DiscussionSPCAransas, Austin, Brazoria, Calhoun, Colorado, Fort Bend and 13 more3 hr
Feb 21, 4:10 AM CSTSevere Thunderstorm WatchSPCAtascosa, Bandera, Bastrop, Bexar, Blanco, Brazos and 26 more6 hr
Feb 21, 4:25 AM CSTTornado WatchSPCAustin, Brazoria, Brazos, Burleson, Calhoun, Colorado and 15 more6 hr
Feb 21, 5:58 AM CSTMesoscale DiscussionSPCAtascosa, Bandera, Bastrop, Bexar, Blanco, Brazos and 26 more2 hr
Feb 21, 9:02 AM CSTMesoscale DiscussionSPCAngelina, Brazoria, Chambers, Cherokee, Fort Bend, Galveston and 22 more58 min
Feb 21, 9:40 AM CSTTornado WatchSPCAngelina, Austin, Brazoria, Brazos, Burleson, Chambers and 25 more6 hr
Feb 21, 11:47 AM CSTMesoscale DiscussionSPCAngelina, Brazoria, Chambers, Fort Bend, Galveston, Grimes and 18 more118 min
Feb 21, 1:30 PM CSTMesoscale DiscussionSPCHardin, Harris, Jasper, Liberty, Montgomery, Newton and 3 more2 hr
Feb 21, 3:32 PM CSTMesoscale DiscussionSPCHardin, Jasper, Liberty, Newton, Orange, Tyler118 min
Feb 21, 3:40 PM CSTTornado WatchSPCAngelina, Chambers, Hardin, Jasper, Jefferson, Nacogdoches and 5 more6 hr
Feb 21, 5:50 PM CSTMesoscale DiscussionSPCAngelina, Chambers, Hardin, Jasper, Jefferson, Nacogdoches and 5 more115 min

Nearby

Mesoscale Discussions in Texas, 2003Every mesoscale discussion in 2003

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; radar from the NEXRAD Level II archive.