Alert archive / Texas / Mesoscale Discussions in 2003

Mesoscale Discussion 1772

July 11, 200321 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jul 11, 2003, 11:46 AM CDT for 21 counties in Texas. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued
Jul 11, 2003, 11:46 AM CDT (16:46 UTC)
Expired
Jul 11, 2003, 1:45 PM CDT
In force
119 min
Issued by
the Storm Prediction Center
All 21 counties

Angelina County, TX, Austin County, TX, Brazos County, TX, Chambers County, TX, Fort Bend County, TX, Grimes County, TX, Hardin County, TX, Harris County, TX, Houston County, TX, Leon County, TX, Liberty County, TX, Madison County, TX, Montgomery County, TX, Orange County, TX, Polk County, TX, San Jacinto County, TX, Trinity County, TX, Tyler County, TX, Walker County, TX, Waller County, TX, Washington County, TX

The radar

The Houston radar (KHGX), 145 km from the middle of the area, began a volume at 16:46 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, 4.8 hours before the alert went out and 231 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 2003-07-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1960 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 2003-07-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -12 square meters per square second.1939Sfc1 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
1960 J/kg
Mixed-layer CIN
-11 J/kg
Mixed-layer LCL
802 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
-12 m²/s²
0-3 km storm-relative helicity
36 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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
Jul 11, 2:00 PM CDTSevere Thunderstorm WatchSPCBastrop, Bell, Brazos, Burleson, Burnet, Caldwell and 14 more5 hr
Jul 11, 4:38 PM CDTMesoscale DiscussionSPCArmstrong, Bailey, Briscoe, Carson, Castro, Collingsworth and 22 more97 min
Jul 11, 5:25 PM CDTSevere Thunderstorm WatchSPCArmstrong, Bailey, Carson, Castro, Cochran, Dallam and 17 more6 hr
Jul 11, 6:15 PM CDTMesoscale DiscussionSPCBastrop, Bell, Brazos, Burleson, Burnet, Caldwell and 14 more60 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.