Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 431

April 14, 20116 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 14, 2011, 9:59 PM CDT for 6 counties in Texas. It was in force for 31 min.

The area

The outline as issued.

The facts

Issued: Apr 14, 2011, 9:59 PM CDT (02:59 UTC)
Expired: Apr 14, 2011, 10:30 PM CDT
In force: 31 min
Issued by: the Storm Prediction Center

Counties Collin County, TX, Dallas County, TX, Denton County, TX, Hopkins County, TX, Hunt County, TX, Rockwall County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 79 km from the middle of the area, began a volume at 03:02 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.

Severe Thunderstorm Watch 137Apr 14, 10:05 PM CDT

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 3.0 hours before the alert went out and 62 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: 1770 J/kg
Mixed-layer CIN: -76 J/kg
Mixed-layer LCL: 1507 m above ground
0-6 km bulk shear: 65 kt
0-1 km storm-relative helicity: 201 m²/s²
0-3 km storm-relative helicity: 302 m²/s²
Significant tornado parameter: 1.3
Supercell composite: 17.3

Open this sounding in Storm Lab

The text

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

581 
ACUS11 KWNS 150259
SWOMCD
SPC MCD 150259 
TXZ000-150330-

MESOSCALE DISCUSSION 0431
NWS STORM PREDICTION CENTER NORMAN OK
0959 PM CDT THU APR 14 2011

AREAS AFFECTED...N-CNTRL TX

CONCERNING...SEVERE POTENTIAL...WATCH NEEDED SOON 

VALID 150259Z - 150330Z

ENVIRONMENTAL CONDITIONS HAVE BECOME FAVORABLE FOR SEVERE STORMS AND
A SEVERE THUNDERSTORM WATCH ISSUANCE WILL BE COORDINATED BETWEEN THE
SPC AND THE AFFECTED LOCAL NATIONAL WEATHER SERVICE OFFICES SHORTLY.
TSTMS ARE BACKBUILDING ALONG A COLD FRONT APPROACHING THE DFW AREA.
VEERED WIND PROFILES WITH STRONG DEEP-LAYER SHEAR WILL PROMOTE A
THREAT FOR DAMAGING WINDS AND LARGE HAIL.

..COHEN.. 04/15/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...FWD...

LAT...LON   32879750 33359739 33419648 33329557 33049541 32799634
            32749722 32879750

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 14, 8:36 PM CDT	Mesoscale Discussion	SPC	Lamar	84 min
Apr 14, 9:06 PM CDT	Tornado Watch	SPC	Bowie, Cooke, Delta, Fannin, Franklin, Grayson and 4 more	6 hr
Apr 14, 10:04 PM CDT	Severe Thunderstorm Watch	SPC	Anderson, Bell, Collin, Coryell, Dallas, Denton and 19 more	4 hr
Apr 14, 11:11 PM CDT	Mesoscale Discussion	SPC	Bowie, Delta, Fannin, Lamar, Red River, Titus	94 min
Apr 14, 11:24 PM CDT	Severe Thunderstorm Watch	SPC	Camp, Cass, Cherokee, Gregg, Harrison, Marion and 7 more	3 hr
Apr 14, 11:56 PM CDT	Mesoscale Discussion	SPC	Anderson, Camp, Cass, Cherokee, Ellis, Freestone and 16 more	94 min
Apr 15, 2:19 AM CDT	Tornado Watch	SPC	Cherokee, Harrison, Nacogdoches, Panola, Rusk, Shelby	8 hr

Nearby

Mesoscale Discussions in Texas, 2011 Every mesoscale discussion in 2011

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.