Alert archive / Texas / Mesoscale Discussions in 2017

Mesoscale Discussion 907

May 28, 201746 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 28, 2017, 6:03 PM CDT for 46 counties in Texas. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued
May 28, 2017, 6:03 PM CDT (23:03 UTC)
Expired
May 28, 2017, 7:00 PM CDT
In force
57 min
Issued by
the Storm Prediction Center
All 46 counties

Anderson County, TX, Bandera County, TX, Bastrop County, TX, Bell County, TX, Bexar County, TX, Blanco County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Caldwell County, TX, Comal County, TX, Coryell County, TX, Dimmit County, TX, Edwards County, TX, Falls County, TX, Freestone County, TX, Frio County, TX, Gillespie County, TX, Grimes County, TX, Guadalupe County, TX, Hays County, TX, Henderson County, TX, Houston County, TX, Kendall County, TX, Kerr County, TX, Kinney County, TX, Lampasas County, TX, Lee County, TX, Leon County, TX, Limestone County, TX, Llano County, TX, Madison County, TX, Maverick County, TX, McLennan County, TX, Medina County, TX, Milam County, TX, Navarro County, TX, Real County, TX, Robertson County, TX, Travis County, TX, Trinity County, TX, Uvalde County, TX, Walker County, TX, Washington County, TX, Williamson County, TX, Zavala County, TX

The radar

The Austin/San Antonio radar (KEWX), 82 km from the middle of the area, began a volume at 23:03 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 12:00Z, 11.1 hours before the alert went out and 225 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 12:00Z on 2017-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3017 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 12:00Z on 2017-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 83 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
3017 J/kg
Mixed-layer CIN
-339 J/kg
Mixed-layer LCL
1097 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
83 m²/s²
0-3 km storm-relative helicity
100 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

575 
ACUS11 KWNS 282303
SWOMCD
SPC MCD 282303 
TXZ000-290000-

Mesoscale Discussion 0907
NWS Storm Prediction Center Norman OK
0603 PM CDT Sun May 28 2017

Areas affected...TX

Concerning...Severe Thunderstorm Watch 293...

Valid 282303Z - 290000Z

The severe weather threat for Severe Thunderstorm Watch 293
continues.

SUMMARY...Strong/severe thunderstorms will continue across WW293.

DISCUSSION...An elongated corridor of robust convection persists
from near DRT-25N AUS-TYR.  This activity has evolved along a
pronounced cold front that should gradually sag southward over the
next few hours.  In addition, water vapor imagery suggests an upper
shortwave-trough is oriented southwest-northeast along this axis of
convection and as this trough shifts east veering deep-layer flow in
its wake should encourage storms across south-central TX to
propagate south.  Large hail is the primary risk with this activity.

..Darrow.. 05/28/2017

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

ATTN...WFO...HGX...FWD...CRP...EWX...SJT...

LAT...LON   29670115 32439593 30909501 28120024 29670115

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 27, 7:12 PM CDTMesoscale DiscussionSPCDallam, Hansford, Hartley, Ochiltree, Sherman2 hr
May 27, 9:07 PM CDTMesoscale DiscussionSPCHansford, Hemphill, Hutchinson, Lipscomb, Ochiltree, Roberts and 1 more53 min
May 27, 11:47 PM CDTMesoscale DiscussionSPCClay, Cooke, Fannin, Grayson, Lamar, Montague and 1 more58 min
May 28, 12:06 AM CDTSevere Thunderstorm WatchSPCBowie, Collin, Cooke, Denton, Fannin, Grayson and 4 more5 hr
May 28, 2:53 AM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Collin, Cooke, Delta and 16 more2 hr
May 28, 4:59 AM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Collin, Delta, Denton and 7 more2 hr
May 28, 1:34 PM CDTMesoscale DiscussionSPCBastrop, Bell, Bexar, Blanco, Burnet, Caldwell and 18 more56 min
May 28, 3:09 PM CDTSevere Thunderstorm WatchSPCAnderson, Atascosa, Austin, Bandera, Bastrop, Bell and 58 more8 hr
May 28, 5:01 PM CDTMesoscale DiscussionSPCGregg, Harrison, Marion, Nacogdoches, Panola, Rusk and 1 more59 min
May 28, 5:19 PM CDTSevere Thunderstorm WatchSPCAngelina, Cherokee, Gregg, Harrison, Marion, Nacogdoches and 6 more4 hr

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; radar from the NEXRAD Level II archive.