Alert archive / Texas / Mesoscale Discussions in 2022

Mesoscale Discussion 511

April 17, 202226 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 17, 2022, 12:51 PM CDT for 26 counties in Texas. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued
Apr 17, 2022, 12:51 PM CDT (17:51 UTC)
Expired
Apr 17, 2022, 2:45 PM CDT
In force
114 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch likely
Chance of a watch
80%
All 26 counties

Bandera County, TX, Bastrop County, TX, Bell County, TX, Bexar County, TX, Blanco County, TX, Burnet County, TX, Caldwell County, TX, Comal County, TX, Edwards County, TX, Frio County, TX, Gillespie County, TX, Guadalupe County, TX, Hays County, TX, Kendall County, TX, Kerr County, TX, Kimble County, TX, Llano County, TX, Mason County, TX, Medina County, TX, Menard County, TX, Real County, TX, Travis County, TX, Uvalde County, TX, Williamson County, TX, Wilson County, TX, Zavala County, TX

The radar

The Austin/San Antonio radar (KEWX), 105 km from the middle of the area, began a volume at 17:53 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

Del Rio, TX (KDRT), launched 12:00Z, 5.9 hours before the alert went out and 198 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 2022-04-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1796 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 2022-04-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 144 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
1796 J/kg
Mixed-layer CIN
-174 J/kg
Mixed-layer LCL
716 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
144 m²/s²
0-3 km storm-relative helicity
193 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.2

Open this sounding in Storm Lab

The text

As transmitted.

204 
ACUS11 KWNS 171751
SWOMCD
SPC MCD 171751 
TXZ000-171945-

Mesoscale Discussion 0511
NWS Storm Prediction Center Norman OK
1251 PM CDT Sun Apr 17 2022

Areas affected...South-central Texas

Concerning...Severe potential...Watch likely 

Valid 171751Z - 171945Z

Probability of Watch Issuance...80 percent

SUMMARY...Isolated thunderstorms are expected to develop in the
coming hours along a cold front across south-central Texas. A
favorable kinematic environment will support the potential for
supercells with large to very large hail.

DISCUSSION...Latest GOES-16 visible imagery reveals the location of
the surface cold front as it continues to push southeast into TX. A
couple of weak thunderstorms have already initiated off this
boundary, but have struggled to mature, quickly becoming displaced
into the cool air to the north. The anemic nature to the prior
convection is likely attributable to lingering mixed-layer
inhibition, which is gradually diminishing as temperatures continue
to slowly warm into the low to mid 80s where skies are mostly clear.
Additional cumulus towers are noted along the front in latest
visible and IR imagery, suggesting the probability for sustained
thunderstorms continues to increase. Storms will likely intensify
further in the coming hours as they move southeast into an air mass
with richer boundary layer moisture (denoted by low 70s dewpoints).
Parcel trajectories will likely deepen as cells encounter this air
mass, allowing for better realization of the elongated wind profiles
over the region. Nearly straight hodographs will support supercell
structures with eventual storm splits. The combination of moderate
instability and strong effective bulk wind shear (40-50 knots) will
support the potential for severe hail (possibly up to 2 inches in
diameter) and damaging winds. Trends will continue to be monitored,
and a watch will likely be needed as soon as sufficient storm
coverage becomes apparent.

..Moore/Hart.. 04/17/2022

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

ATTN...WFO...FWD...EWX...SJT...

LAT...LON   30380021 30929992 30949941 31039876 31239791 31379754
            30889697 30159711 29489749 28989835 28759911 28819991
            29200023 29670036 30030037 30380021

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 16, 7:25 PM CDTMesoscale DiscussionSPCBandera, Bastrop, Bexar, Blanco, Burnet, Caldwell and 16 more2 hr
Apr 17, 11:24 AM CDTMesoscale DiscussionSPCCass, Gregg, Harrison, Marion, Morris, Panola and 3 more3 hr
Apr 17, 12:29 PM CDTSevere Thunderstorm WatchSPCCamp, Cass, Gregg, Harrison, Marion, Morris and 6 more7 hr
Apr 17, 1:42 PM CDTSevere Thunderstorm WatchSPCAtascosa, Bandera, Bastrop, Bexar, Blanco, Burnet and 16 more6 hr
Apr 17, 2:55 PM CDTMesoscale DiscussionSPCShelby3 hr
Apr 17, 3:33 PM CDTMesoscale DiscussionSPCBandera, Bastrop, Bexar, Blanco, Caldwell, Comal and 12 more117 min
Apr 17, 4:32 PM CDTMesoscale DiscussionSPCAngelina, Brazos, Burleson, Grimes, Houston, Leon and 11 more88 min
Apr 17, 5:27 PM CDTMesoscale DiscussionSPCAtascosa, Bexar, Frio, Medina, Uvalde, Wilson and 1 more93 min

Nearby

Mesoscale Discussions in Texas, 2022Every mesoscale discussion in 2022

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.