Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 993

May 31, 201211 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 31, 2012, 6:02 AM CDT for 11 counties in Texas. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued: May 31, 2012, 6:02 AM CDT (11:02 UTC)
Expired: May 31, 2012, 7:30 AM CDT
In force: 88 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Brazos County, TX, Falls County, TX, Freestone County, TX, Houston County, TX, Leon County, TX, Limestone County, TX, Madison County, TX, Polk County, TX, Robertson County, TX, Trinity County, TX, Walker County, TX

The radar

The Ft Hood radar (KGRK), 145 km from the middle of the area, began a volume at 11:02 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 nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 11.0 hours before the alert went out and 218 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: 451 J/kg
Mixed-layer CIN: -374 J/kg
Mixed-layer LCL: 2223 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: -119 m²/s²
0-3 km storm-relative helicity: 61 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

843 
ACUS11 KWNS 311103
SWOMCD
SPC MCD 311102
TXZ000-311230-

MESOSCALE DISCUSSION 0993
NWS STORM PREDICTION CENTER NORMAN OK
0602 AM CDT THU MAY 31 2012

AREAS AFFECTED...PARTS OF CNTRL INTO SERN TX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 311102Z - 311230Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...SOME HAIL AND PERHAPS STRONG GUSTY WINDS MAY ACCOMPANY A
SOUTHEASTWARD PROPAGATING CLUSTER OF STORMS THIS MORNING.  A WW IS
NOT CURRENTLY ANTICIPATED...BUT TRENDS WILL BE MONITORED FOR THE
POSSIBILITY OF INCREASING SEVERE WEATHER POTENTIAL.

DISCUSSION...VIGOROUS CONVECTIVE DEVELOPMENT...INITIATED OVER NORTH
CENTRAL TEXAS SEVERAL HOURS AGO...ASSOCIATED WITH GRAVITY WAVES
GENERATED BY A NOW WEAKENING CLUSTER OF STORMS ACROSS THE OZARK
PLATEAU... HAS SHOWN A SUBSTANTIVE RECENT INCREASE IN COVERAGE AND
INTENSITY TO THE SOUTH OF THE DALLAS-FORT WORTH METROPLEX.  THIS MAY
BE AIDED BY MODEST SOUTHERLY INFLOW OF INCREASING MOIST AIR
CHARACTERIZED BY SURFACE DEW POINTS NEAR 70F.  IT IS POSSIBLE THAT A
30-40 KT WEST NORTHWESTERLY MID-LEVEL JET STREAK IN THE WAKE OF
ANOTHER CLUSTER OF STORMS...RECENTLY WEAKENING ACROSS THE
ARKLATEX...HAS ENHANCED ACTIVITY...WHICH MAY CONTINUE TO BECOME
BETTER ORGANIZED OVER THE NEXT COUPLE OF HOURS.  THE POTENTIAL
LONGEVITY OF THIS EVOLVING CLUSTER OF STORMS REMAINS UNCLEAR... BUT
A DOWNBURST DOES NOT APPEAR OUT OF THE QUESTION...ACCOMPANIED BY
SURFACE GUSTS THAT COULD APPROACH SEVERE LIMITS... EAST/NORTHEAST OF
THE TEMPLE AND COLLEGE STATION AREAS INTO THE VICINITY OF LUFKIN
BETWEEN NOW AND 12-14Z.

..KERR/MEAD.. 05/31/2012

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

ATTN...WFO...LCH...SHV...HGX...FWD...

LAT...LON   31269709 31589706 31779653 31679557 31509511 31109460
            30829444 30589597 30629629 31269709

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 30, 7:37 PM CDT	Mesoscale Discussion	SPC	Blanco, Brown, Burnet, Callahan, Coleman, Comanche and 22 more	113 min
May 30, 8:38 PM CDT	Mesoscale Discussion	SPC	Armstrong, Briscoe, Carson, Childress, Collingsworth, Cottle and 13 more	97 min
May 30, 10:15 PM CDT	Mesoscale Discussion	SPC	Blanco, Brown, Burnet, Callahan, Coleman, Comanche and 22 more	2 hr
May 31, 9:47 AM CDT	Mesoscale Discussion	SPC	Chambers, Hardin, Harris, Jasper, Jefferson, Liberty and 5 more	58 min
May 31, 10:41 AM CDT	Severe Thunderstorm Watch	SPC	Hardin, Jasper, Jefferson, Newton, Orange	6 hr
May 31, 6:21 PM CDT	Mesoscale Discussion	SPC	Brewster, Jeff Davis, Pecos, Presidio, Reeves	2 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.