Alert archive / Texas / Mesoscale Discussions in 2017

Mesoscale Discussion 913

May 28, 20179 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 28, 2017, 9:41 PM CDT for 9 counties in Texas. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued
May 28, 2017, 9:41 PM CDT (02:41 UTC)
Expired
May 28, 2017, 10:45 PM CDT
In force
64 min
Issued by
the Storm Prediction Center

Counties Brooks County, TX, Duval County, TX, Jim Hogg County, TX, Jim Wells County, TX, La Salle County, TX, Live Oak County, TX, McMullen County, TX, Webb County, TX, Zapata County, TX

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 00:00Z, 2.7 hours before the alert went out and 175 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 2017-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2745 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Corpus Christi, TX at 00:00Z on 2017-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 square meters per square second.193958Sfc1 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
2745 J/kg
Mixed-layer CIN
-174 J/kg
Mixed-layer LCL
1028 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
63 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

As transmitted.

043 
ACUS11 KWNS 290241
SWOMCD
SPC MCD 290241 
TXZ000-290345-

Mesoscale Discussion 0913
NWS Storm Prediction Center Norman OK
0941 PM CDT Sun May 28 2017

Areas affected...South TX

Concerning...Severe Thunderstorm Watch 297...

Valid 290241Z - 290345Z

The severe weather threat for Severe Thunderstorm Watch 297
continues.

SUMMARY...Isolated severe threat continues in the short term across
the northwestern half of WW297.

DISCUSSION...Thunderstorms have been slow to advance east across
Webb/La Salle Counties this evening.  However, additional convection
upstream is approaching this nearly stationary activity and some
southeastward movement may occur over the next hour or so. 
Considerable moisture/instability reside across south TX and an MCS
may ultimately evolve across this region.

..Darrow.. 05/29/2017

...Please see www.spc.noaa.gov for graphic product...

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

LAT...LON   28279983 28739804 27019803 26539984 28279983

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 28, 7:08 PM CDTSevere Thunderstorm WatchSPCHardin, Jasper, Newton, Orange, Tyler6 hr
May 28, 7:19 PM CDTMesoscale DiscussionSPCDuval, Jim Hogg, La Salle, Live Oak, McMullen, Webb and 1 more56 min
May 28, 7:34 PM CDTMesoscale DiscussionSPCCherokee, Gregg, Harrison, Houston, Nacogdoches, Panola and 5 more56 min
May 28, 7:40 PM CDTSevere Thunderstorm WatchSPCBrooks, Cameron, Duval, Hidalgo, Jim Hogg, Jim Wells and 10 more8 hr
May 28, 9:16 PM CDTMesoscale DiscussionSPCHardin, Jasper, Newton, Orange, Sabine, Tyler59 min
May 29, 2:02 AM CDTMesoscale DiscussionSPCAransas, Brooks, Cameron, Duval, Hidalgo, Jim Wells and 6 more118 min

Nearby

Mesoscale Discussions in Texas, 2017Every mesoscale discussion in 2017

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.