Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 1747

August 12, 2012Bryan County, Choctaw County, Pushmataha County, Oklahoma; 15 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Aug 12, 2012, 8:41 PM CDT for Bryan County, Choctaw County, Pushmataha County, Oklahoma; 15 counties in Texas. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued: Aug 12, 2012, 8:41 PM CDT (01:41 UTC)
Expired: Aug 12, 2012, 9:45 PM CDT
In force: 64 min
Issued by: the Storm Prediction Center

Counties Bryan County, OK, Choctaw County, OK, Pushmataha County, OK, Callahan County, TX, Coke County, TX, Coleman County, TX, Collin County, TX, Comanche County, TX, Dallas County, TX, Erath County, TX, Fannin County, TX, Hood County, TX, Johnson County, TX, Nolan County, TX, Rockwall County, TX, Somervell County, TX, Tarrant County, TX, Taylor County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 90 km from the middle of the area, began a volume at 01:43 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

Fort Worth, TX (KFWD), launched 00:00Z, 1.7 hours before the alert went out and 91 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: 411 J/kg
Mixed-layer CIN: -76 J/kg
Mixed-layer LCL: 3177 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 138 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.4

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.

Issued	Product	Office	Counties	Lasted
Aug 12, 7:16 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Cherokee, Choctaw, Haskell, Latimer, LeFlore and 6 more	4 hr
Aug 12, 10:26 PM CDT	Mesoscale Discussion	SPC	Adair, Haskell, LeFlore, McCurtain, Muskogee, Sequoyah	94 min
Aug 12, 10:49 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Cherokee, Craig, Delaware, Haskell, Latimer and 7 more	5 hr
Aug 13, 1:45 AM CDT	Mesoscale Discussion	SPC	Adair, Haskell, Latimer, LeFlore, Sequoyah	2 hr

Nearby

Mesoscale Discussions in Texas, 2012 Mesoscale Discussions in Oklahoma, 2012 Every 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.