Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 972

May 29, 201212 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 29, 2012, 8:54 PM CDT for 12 counties in Texas. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: May 29, 2012, 8:54 PM CDT (01:54 UTC)
Expired: May 29, 2012, 10:30 PM CDT
In force: 96 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Collin County, TX, Dallas County, TX, Denton County, TX, Hood County, TX, Jack County, TX, Johnson County, TX, Kaufman County, TX, Palo Pinto County, TX, Parker County, TX, Rockwall County, TX, Tarrant County, TX, Wise County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 33 km from the middle of the area, began a volume at 01:55 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 320May 30, 12:45 AM CDT

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 1.9 hours before the alert went out and 6 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: 1364 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 2060 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: -4 m²/s²
0-3 km storm-relative helicity: 175 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 7.6

Open this sounding in Storm Lab

The text

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

143 
ACUS11 KWNS 300154
SWOMCD
SPC MCD 300154 
TXZ000-300330-

MESOSCALE DISCUSSION 0972
NWS STORM PREDICTION CENTER NORMAN OK
0854 PM CDT TUE MAY 29 2012

AREAS AFFECTED...N-CNTRL TX

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 300154Z - 300330Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...ISOLATED TSTM MAY BEGIN PRODUCE SEVERE WIND/HAIL WITHIN
THE NEXT HOUR. AREA WILL BE MONITORED FOR ADDITIONAL DEVELOPMENT AND
A POSSIBLE WW.

DISCUSSION...ISOLATED TSTM DEVELOPED RAPIDLY ALONG A DIFFERENTIAL
HEATING BOUNDARY RELATED GENERATED BY THE ANVIL FROM A TSTM NEAR
SPS. 00Z FWD SOUNDING INDICATES AN UNSTABLE ENVIRONMENT WITH THE
POTENTIAL TO PRODUCE LARGE HAIL. CURRENT MOTION/REFLECTIVITY
STRUCTURE SUGGEST THE STORM IS ELEVATED BUT...GIVEN ITS CURRENT
ENVIRONMENT...COULD BECOME QUICKLY SFC BASED. UNCERTAINTY REGARDING
THE DEVELOPMENT OF ADDITIONAL STORMS IS CURRENTLY KEEPING WATCH
PROBABILITY BELOW 50 PERCENT BUT THE AREA WILL BE MONITORED FOR
ADDITIONAL DEVELOPMENT AND A POSSIBLE WW.

..MOSIER/HART.. 05/30/2012

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

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

LAT...LON   32589826 32979844 33509839 33489763 33569677 33569655
            33209612 32659605 32479634 32439655 32399693 32369734
            32389779 32589826

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 29, 11:28 PM CDT	Mesoscale Discussion	SPC	Cooke, Fannin, Grayson, Lamar, Montague	62 min
May 30, 12:43 AM CDT	Severe Thunderstorm Watch	SPC	Camp, Collin, Cooke, Dallas, Delta, Denton and 19 more	7 hr
May 30, 2:43 AM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Camp, Cass, Clay, Collin and 37 more	92 min
May 30, 5:07 AM CDT	Mesoscale Discussion	SPC	Anderson, Camp, Cherokee, Collin, Dallas, Denton and 28 more	83 min
May 30, 2:58 PM CDT	Mesoscale Discussion	SPC	Briscoe, Childress, Collingsworth, Cottle, Dickens, Donley and 8 more	62 min
May 30, 3:38 PM CDT	Tornado Watch	SPC	Baylor, Briscoe, Childress, Collingsworth, Cottle, Dickens and 15 more	5 hr
May 30, 4:52 PM CDT	Mesoscale Discussion	SPC	Brown, Callahan, Coke, Coleman, Concho, Eastland and 17 more	83 min
May 30, 5:11 PM CDT	Tornado Watch	SPC	Brown, Burnet, Callahan, Coke, Coleman, Comanche and 27 more	6 hr
May 30, 6:13 PM CDT	Severe Thunderstorm Watch	SPC	Archer, Baylor, Clay, Cooke, Denton, Jack and 5 more	8 hr

Nearby

Mesoscale Discussions in Texas, 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.