Alert archive / Texas / Mesoscale Discussions in 2007

Mesoscale Discussion 274

March 12, 200716 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 12, 2007, 5:09 AM CDT for 16 counties in Texas. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: Mar 12, 2007, 5:09 AM CDT (10:09 UTC)
Expired: Mar 12, 2007, 6:45 AM CDT
In force: 96 min
Issued by: the Storm Prediction Center

Counties Austin County, TX, Brazoria County, TX, Chambers County, TX, Colorado County, TX, Fort Bend County, TX, Galveston County, TX, Grimes County, TX, Harris County, TX, Jackson County, TX, Liberty County, TX, Matagorda County, TX, Montgomery County, TX, San Jacinto County, TX, Waller County, TX, Washington County, TX, Wharton County, TX

The radar

The Houston radar (KHGX), 67 km from the middle of the area, began a volume at 10:08 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 nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 10.2 hours before the alert went out and 243 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 9 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 968 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 47 m²/s²
0-3 km storm-relative helicity: 53 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.

Issued	Product	Office	Counties	Lasted
Mar 11, 9:09 PM CDT	Mesoscale Discussion	SPC	Atascosa, Bandera, Bexar, Blanco, Burnet, Caldwell and 19 more	2 hr
Mar 11, 11:16 PM CDT	Mesoscale Discussion	SPC	Atascosa, Bexar, Caldwell, Comal, Dimmit, Frio and 8 more	89 min
Mar 12, 1:39 AM CDT	Mesoscale Discussion	SPC	Austin, Bastrop, Bee, Colorado, DeWitt, Fayette and 13 more	2 hr
Mar 12, 4:01 AM CDT	Tornado Watch	SPC	Austin, Brazoria, Chambers, Fort Bend, Galveston, Harris and 5 more	4 hr
Mar 12, 6:10 AM CDT	Mesoscale Discussion	SPC	Hardin, Jasper, Jefferson, Newton, Orange	95 min

Nearby

Mesoscale Discussions in Texas, 2007 Every mesoscale discussion in 2007

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.