Alert archive / Texas / Mesoscale Discussions in 2016

Mesoscale Discussion 374

April 12, 201623 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2016, 7:26 PM CDT for 23 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Apr 12, 2016, 7:26 PM CDT (00:26 UTC)
Expired
Apr 12, 2016, 10:00 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 23 counties

Atascosa County, TX, Bandera County, TX, Bastrop County, TX, Bexar County, TX, Caldwell County, TX, Comal County, TX, DeWitt County, TX, Edwards County, TX, Frio County, TX, Gonzales County, TX, Guadalupe County, TX, Hays County, TX, Karnes County, TX, Kendall County, TX, Kerr County, TX, Kinney County, TX, Lavaca County, TX, Maverick County, TX, Medina County, TX, Real County, TX, Uvalde County, TX, Wilson County, TX, Zavala County, TX

The radar

The Austin/San Antonio radar (KEWX), 57 km from the middle of the area, began a volume at 00:27 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

Corpus Christi, TX (KCRP), launched 00:00Z, 0.4 hours before the alert went out and 219 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, Corpus Christi, TX at 00:00Z on 2016-04-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 634 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, Corpus Christi, TX at 00:00Z on 2016-04-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 34 square meters per square second.1939587897Sfc1 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
634 J/kg
Mixed-layer CIN
-170 J/kg
Mixed-layer LCL
912 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
34 m²/s²
0-3 km storm-relative helicity
247 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

As transmitted.

659 
ACUS11 KWNS 130027
SWOMCD
SPC MCD 130026 
TXZ000-130300-

MESOSCALE DISCUSSION 0374
NWS STORM PREDICTION CENTER NORMAN OK
0726 PM CDT TUE APR 12 2016

AREAS AFFECTED...SW AND CNTRL TX

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 130026Z - 130300Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...A THREAT FOR ISOLATED LARGE HAIL AND WIND DAMAGE IS
EXPECTED TO CONTINUE DEVELOPING ACROSS PARTS OF SW AND CNTRL TX OVER
THE NEXT FEW HOURS. WW ISSUANCE MAY BE NEEDED ACROSS THE REGION
EARLY THIS EVENING.

DISCUSSION...LATEST SFC ANALYSIS SHOWS A QUASI-STATIONARY FRONTAL
BOUNDARY LOCATED FROM SOUTH OF DEL RIO EXTENDING ESEWD TO SOUTH OF
SAN ANTONIO AND THEN ENEWD TOWARD THE UPPER TX COAST. NEAR AND TO
THE SOUTH OF THE BOUNDARY...SFC DEWPOINTS ARE IN THE MID 60S TO NEAR
70 F WITH 1000 TO 1200 J/KG OF MLCAPE ESTIMATED BY MESOSCALE
ANALYSIS. THIS IS CONFIRMED BY THE DEL RIO 00Z SOUNDING WHICH SHOWS
65 KT OF 0-6 KM SHEAR AND SOME DIRECTIONAL SHEAR IN THE LOW LEVELS.
THIS ENVIRONMENT WILL LIKELY SUPPORT SUPERCELLS WITH ISOLATED LARGE
HAIL AND WIND DAMAGE. SHORT-TERM MODELS INCLUDING THE HRRR SUGGEST
THAT THE STRONGER UPDRAFTS WILL REMAIN TO THE NORTH OF THE BOUNDARY
AND THAT THE MAIN SEVERE WEATHER THREAT WILL REMAIN OVER WRN PARTS
OF THE TX HILL COUNTRY OVER THE NEXT COUPLE OF HOURS. AS CELLS
INTENSIFY AND A CLUSTER OF STRONG TO SEVERE STORMS DEVELOPS LATER
THIS EVENING...THE SAN ANTONIO AREA MAY ALSO BE IMPACTED.

..BROYLES/THOMPSON.. 04/13/2016

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

ATTN...WFO...CRP...EWX...

LAT...LON   30229722 29409676 28919737 28619832 28569938 28560052
            30040072 30219907 30229722

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 12, 7:45 PM CDTSevere Thunderstorm WatchSPCAtascosa, Bandera, Bee, Bexar, Blanco, Caldwell and 26 more5 hr
Apr 12, 9:43 PM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bee, Bexar, Blanco, Caldwell and 25 more92 min
Apr 12, 11:06 PM CDTMesoscale DiscussionSPCAustin, Brazoria, Colorado, DeWitt, Fayette, Fort Bend and 7 more114 min
Apr 12, 11:26 PM CDTSevere Thunderstorm WatchSPCAustin, Brazoria, Chambers, Colorado, Fort Bend, Galveston and 5 more6 hr
Apr 13, 2:01 AM CDTMesoscale DiscussionSPCBrazoria, Chambers, Fort Bend, Galveston, Harris, Jackson and 3 more119 min

Nearby

Mesoscale Discussions in Texas, 2016Every mesoscale discussion in 2016

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.