Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 984

May 30, 201223 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 30, 2012, 4:52 PM CDT for 23 counties in Texas. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
May 30, 2012, 4:52 PM CDT (21:52 UTC)
Expired
May 30, 2012, 6:15 PM CDT
In force
83 min
Issued by
the Storm Prediction Center
Chance of a watch
95%
All 23 counties

Brown County, TX, Callahan County, TX, Coke County, TX, Coleman County, TX, Concho County, TX, Eastland County, TX, Fisher County, TX, Haskell County, TX, Irion County, TX, Jones County, TX, McCulloch County, TX, Menard County, TX, Mitchell County, TX, Nolan County, TX, Runnels County, TX, San Saba County, TX, Schleicher County, TX, Scurry County, TX, Shackelford County, TX, Sterling County, TX, Stonewall County, TX, Taylor County, TX, Tom Green County, TX

The radar

The San Angelo radar (KSJT), 59 km from the middle of the area, began a volume at 21:54 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.

The nearest sounding before it

Midland Regional, TX (KMAF), launched 12:00Z, 9.9 hours before the alert went out and 203 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-pSkew-T log-p diagram, Midland Regional, TX at 12:00Z on 2012-05-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1761 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Midland Regional, TX at 12:00Z on 2012-05-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 114 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
1761 J/kg
Mixed-layer CIN
-189 J/kg
Mixed-layer LCL
1809 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
114 m²/s²
0-3 km storm-relative helicity
127 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

964 
ACUS11 KWNS 302152
SWOMCD
SPC MCD 302152 
TXZ000-302315-

MESOSCALE DISCUSSION 0984
NWS STORM PREDICTION CENTER NORMAN OK
0452 PM CDT WED MAY 30 2012

AREAS AFFECTED...W CNTRL TX

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 302152Z - 302315Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...ISOLATED SUPERCELLS ARE LIKELY TO FORM AND PERSIST OVER
THE NEXT FEW HOURS...WITH A DISTINCT GIANT HAIL...DAMAGING WIND AND
ISOLATED TORNADO THREAT.

DISCUSSION...STORMS ARE BEGINNING TO ERUPT ALONG THE DRYLINE WHERE
TEMPERATURES EXCEED 100 F. MEANWHILE...SELY SURFACE WINDS ARE
MAINTAINING MID 60S F DEWPOINTS...CREATING EXTREME INSTABILITY WHEN
COUPLED WITH STEEP LAPSE RATE PROFILES ALOFT.

THE TURNING WINDS WITH HEIGHT ARE ALSO FAVORABLE FOR
SUPERCELLS...AND DESPITE MARGINAL T/TD SPREADS INITIALLY....A
TORNADO OR TWO IS POSSIBLE. LOCALLY SIGNIFICANT DAMAGING WINDS MAY
ALSO OCCUR BENEATH THESE SUPERCELLS.

..JEWELL/CORFIDI.. 05/30/2012

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

ATTN...WFO...FWD...EWX...SJT...LUB...MAF...

LAT...LON   31190156 31780108 32460096 32880099 33399997 33059951
            32269862 31659870 30929866 30749906 30709984 30690031
            31190156

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 29, 8:54 PM CDTMesoscale DiscussionSPCCollin, Dallas, Denton, Hood, Jack, Johnson and 6 more96 min
May 29, 11:28 PM CDTMesoscale DiscussionSPCCooke, Fannin, Grayson, Lamar, Montague62 min
May 30, 12:43 AM CDTSevere Thunderstorm WatchSPCCamp, Collin, Cooke, Dallas, Delta, Denton and 19 more7 hr
May 30, 2:43 AM CDTMesoscale DiscussionSPCArcher, Baylor, Camp, Cass, Clay, Collin and 37 more92 min
May 30, 5:07 AM CDTMesoscale DiscussionSPCAnderson, Camp, Cherokee, Collin, Dallas, Denton and 28 more83 min
May 30, 2:58 PM CDTMesoscale DiscussionSPCBriscoe, Childress, Collingsworth, Cottle, Dickens, Donley and 8 more62 min
May 30, 3:38 PM CDTTornado WatchSPCBaylor, Briscoe, Childress, Collingsworth, Cottle, Dickens and 15 more5 hr
May 30, 5:11 PM CDTTornado WatchSPCBrown, Burnet, Callahan, Coke, Coleman, Comanche and 27 more6 hr
May 30, 6:13 PM CDTSevere Thunderstorm WatchSPCArcher, Baylor, Clay, Cooke, Denton, Jack and 5 more8 hr

Nearby

Mesoscale Discussions in Texas, 2012Every 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.