Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 1737

August 10, 2012Beauregard Parish, Louisiana; 30 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Aug 10, 2012, 3:58 PM CDT for Beauregard Parish, Louisiana; 30 counties in Texas. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued
Aug 10, 2012, 3:58 PM CDT (20:58 UTC)
Expired
Aug 10, 2012, 5:30 PM CDT
In force
92 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 31 counties

Beauregard Parish, LA, Austin County, TX, Bastrop County, TX, Bexar County, TX, Brazos County, TX, Burleson County, TX, Caldwell County, TX, Colorado County, TX, Comal County, TX, Fayette County, TX, Gonzales County, TX, Grimes County, TX, Guadalupe County, TX, Hardin County, TX, Harris County, TX, Hays County, TX, Jasper County, TX, Kendall County, TX, Lavaca County, TX, Lee County, TX, Liberty County, TX, Montgomery County, TX, Newton County, TX, Polk County, TX, San Jacinto County, TX, Travis County, TX, Tyler County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Wilson County, TX

The radar

The Houston radar (KHGX), 128 km from the middle of the area, began a volume at 20:58 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, 9.0 hours before the alert went out and 277 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 2012-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2090 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 2012-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 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
2090 J/kg
Mixed-layer CIN
-90 J/kg
Mixed-layer LCL
1009 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
99 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.4

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
Aug 10, 4:31 PM CDTSevere Thunderstorm WatchSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 5 more5 hr
Aug 10, 6:57 PM CDTMesoscale DiscussionSPCAllen, Beauregard, Calcasieu, Cameron, Evangeline, Jefferson Davis63 min

Nearby

Mesoscale Discussions in Texas, 2012Mesoscale Discussions in Louisiana, 2012Every mesoscale discussion in 2012

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.