Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 780

May 27, 202113 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 27, 2021, 10:24 PM CDT for 13 counties in Texas. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: May 27, 2021, 10:24 PM CDT (03:24 UTC)
Expired: May 28, 2021, 12:00 AM CDT
In force: 96 min
Issued by: the Storm Prediction Center
Concerning: Severe thunderstorm watch 216

Counties Archer County, TX, Baylor County, TX, Clay County, TX, Haskell County, TX, Jack County, TX, Knox County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Stephens County, TX, Throckmorton County, TX, Wise County, TX, Young County, TX

The radar

The Altus AFB radar (KFDR), 101 km from the middle of the area, began a volume at 03:28 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

Fort Worth, TX (KFWD), launched 00:00Z, 3.4 hours before the alert went out and 156 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1480 J/kg
Mixed-layer CIN: -150 J/kg
Mixed-layer LCL: 1331 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 124 m²/s²
0-3 km storm-relative helicity: 203 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 3.7

Open this sounding in Storm Lab

The text

As transmitted.

071 
ACUS11 KWNS 280324
SWOMCD
SPC MCD 280324 
OKZ000-TXZ000-280500-

Mesoscale Discussion 0780
NWS Storm Prediction Center Norman OK
1024 PM CDT Thu May 27 2021

Areas affected...Parts of northwestern into north central Texas

Concerning...Severe Thunderstorm Watch 216...

Valid 280324Z - 280500Z

The severe weather threat for Severe Thunderstorm Watch 216
continues.

SUMMARY...Some risk for hail and gusty winds may continue in
stronger storms spreading south of the Red River through at least
Midnight-2 AM CDT. However, severe weather potential, in general,
appears low enough that a new severe weather watch will not be
needed.

DISCUSSION...Steep lapse rates, associated with remnants of the more
strongly heated and deeply mixed boundary layer and warmer elevated
mixed-layer air, are still supporting large CAPE in the vicinity of
weak low pressure at the intersection of a southward advancing cold
front and conglomerate convective outflow boundary.  Given this
environment, it is possible that at least weak large-scale ascent,
aided by low-level convergence and warm advection focused to the
northeast of the low, could continue to support vigorous
thunderstorm development another several hours.  In the presence of
strong shear within the cloud-bearing layer, generally above the
leading edge of the southward advancing cooler air, some of this
activity might continue to pose some risk for severe hail and strong
surface gusts.  However, with the instability gradually waning, and
southerly low-level pre-frontal/cold pool flow remaining generally
weak, there is little to suggest a substantive increase in storm
intensities and severe weather potential beyond what is ongoing now,
as progresses south of the Red River.

..Kerr.. 05/28/2021

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

ATTN...WFO...FWD...OUN...SJT...LUB...

LAT...LON   33879884 33909748 32669760 32519877 33330024 34119970
            33879884

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 28, 2:33 AM CDT	Mesoscale Discussion	SPC	Collin, Denton, Hunt, Rockwall, Wise	117 min
May 28, 5:10 AM CDT	Mesoscale Discussion	SPC	Briscoe, Castro, Childress, Cottle, Floyd, Foard and 7 more	2 hr
May 28, 11:16 AM CDT	Mesoscale Discussion	SPC	Bell, Bosque, Brazos, Brown, Burleson, Coleman and 19 more	89 min
May 28, 12:14 PM CDT	Severe Thunderstorm Watch	SPC	Bell, Bosque, Brazos, Burleson, Burnet, Comanche and 22 more	7 hr
May 28, 12:49 PM CDT	Mesoscale Discussion	SPC	Brewster, Pecos, Presidio, Terrell	86 min
May 28, 1:03 PM CDT	Mesoscale Discussion	SPC	Andrews, Bailey, Borden, Cochran, Dawson, Ector and 11 more	57 min
May 28, 2:33 PM CDT	Mesoscale Discussion	SPC	Andrews, Borden, Brown, Coke, Coleman, Concho and 35 more	117 min
May 28, 2:45 PM CDT	Severe Thunderstorm Watch	SPC	Brewster, Culberson, Jeff Davis, Loving, Pecos, Reeves and 3 more	9 hr
May 28, 3:41 PM CDT	Severe Thunderstorm Watch	SPC	Andrews, Brown, Coke, Coleman, Concho, Crane and 20 more	8 hr
May 28, 3:42 PM CDT	Mesoscale Discussion	SPC	Bell, Brazos, Brown, Burleson, Burnet, Comanche and 12 more	93 min
May 28, 5:54 PM CDT	Mesoscale Discussion	SPC	Atascosa, Austin, Bandera, Bastrop, Bexar, Blanco and 29 more	96 min
May 28, 6:20 PM CDT	Severe Thunderstorm Watch	SPC	Atascosa, Austin, Bandera, Bastrop, Bexar, Blanco and 32 more	5 hr
May 28, 6:49 PM CDT	Mesoscale Discussion	SPC	Bailey, Deaf Smith, Parmer	86 min

Nearby

Mesoscale Discussions in Texas, 2021 Every mesoscale discussion in 2021

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.