Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 710

May 20, 20158 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 20, 2015, 7:39 PM CDT for 8 counties in Texas. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
May 20, 2015, 7:39 PM CDT (00:39 UTC)
Expired
May 20, 2015, 9:15 PM CDT
In force
96 min
Issued by
the Storm Prediction Center

Counties Crockett County, TX, Gillespie County, TX, Kerr County, TX, Kimble County, TX, Mason County, TX, Menard County, TX, Schleicher County, TX, Sutton County, TX

The radar

The San Angelo radar (KSJT), 95 km from the middle of the area, began a volume at 00:40 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

Del Rio, TX (KDLF), launched 00:00Z, 0.7 hours before the alert went out and 130 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, Del Rio, TX at 00:00Z on 2015-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1721 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, Del Rio, TX at 00:00Z on 2015-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -24 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
1721 J/kg
Mixed-layer CIN
-28 J/kg
Mixed-layer LCL
1071 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
-24 m²/s²
0-3 km storm-relative helicity
-2 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

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

671 
ACUS11 KWNS 210039
SWOMCD
SPC MCD 210039 
TXZ000-210215-

MESOSCALE DISCUSSION 0710
NWS STORM PREDICTION CENTER NORMAN OK
0739 PM CDT WED MAY 20 2015

AREAS AFFECTED...EDWARDS PLATEAU...ADJACENT AREAS OF RIO GRANDE
VALLEY...INTO S CNTRL TX

CONCERNING...SEVERE THUNDERSTORM WATCH 192...

VALID 210039Z - 210215Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 192
CONTINUES.

SUMMARY...THE RISK FOR SEVERE HAIL CONTINUES WITH STRONGER STORMS
DEVELOPING SOUTHWARD/SOUTHEASTWARD ACROSS THE EDWARDS
PLATEAU...TOWARD THE HILL COUNTRY...THIS EVENING.  AN INCREASING
RISK FOR STRONG WIND GUSTS REMAINS POSSIBLE.

DISCUSSION...WIDELY SCATTERED VIGOROUS CONVECTIVE DEVELOPMENT
SOUTH/WEST OF THE RIO GRANDE RIVER IS REMAINING GENERALLY CONFINED
TO THE HIGHER TERRAIN.  HOWEVER...AN INCREASE IN THUNDERSTORM
ACTIVITY HAS OCCURRED ALONG THE FRONT TO THE WEST/SOUTHWEST OF THE
INITIAL INTENSE STORMS THAT FORMED NEAR SAN ANGELO.  THE LEAD
STRONGER STORMS HAVE SHIFTED TO THE SOUTH OF SAN ANGELO...SUPPORTED
BY A PERSISTENT AREA OF ENHANCED LOW-LEVEL CONVERGENCE...AND MODEST
INFLOW OF MOIST UNSTABLE AIR THAT APPEARS CHARACTERIZED BY MIXED
LAYER CAPE OF 2000-3000 J/KG.  AT LEAST SOME STRENGTHENING OF
SOUTHERLY LOW-LEVEL INFLOW STILL APPEARS POSSIBLE THIS EVENING...
WHICH COULD SUPPORT FURTHER UPSCALE CONVECTIVE GROWTH ALONG THE I-10
CORRIDOR...THROUGH JUNCTION BY AROUND 02Z...PERHAPS AS CLOSE TO SAN
ANTONIO AS KENDALL/BLANCO COUNTIES BY 04Z.  IF THIS OCCURS...IT
PROBABLY WOULD BE ACCOMPANIED BY INCREASING POTENTIAL FOR STRONG
SURFACE GUSTS...IN ADDITION TO A CONTINUING RISK FOR SEVERE HAIL.

..KERR.. 05/21/2015

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

ATTN...WFO...EWX...SJT...MAF...

LAT...LON   30910060 30899987 30679890 30209867 29949943 30360048
            30270150 30210335 30800212 30910060

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 20, 10:52 PM CDTMesoscale DiscussionSPCBandera, Bastrop, Bexar, Blanco, Burnet, Caldwell and 16 more83 min
May 21, 7:08 AM CDTMesoscale DiscussionSPCHidalgo, Jim Hogg, Starr, Zapata67 min
May 21, 5:33 PM CDTMesoscale DiscussionSPCEl Paso, Hudspeth117 min

Nearby

Mesoscale Discussions in Texas, 2015Every mesoscale discussion in 2015

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.