Alert archive / Texas / Mesoscale Discussions in 2019

Mesoscale Discussion 511

May 3, 20199 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 3, 2019, 5:45 AM CDT for 9 counties in Texas. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued: May 3, 2019, 5:45 AM CDT (10:45 UTC)
Expired: May 3, 2019, 6:45 AM CDT
In force: 60 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

Counties Brooks County, TX, Cameron County, TX, Hidalgo County, TX, Jim Hogg County, TX, Kenedy County, TX, Kleberg County, TX, Starr County, TX, Willacy County, TX, Zapata County, TX

The radar

The Corpus Christi radar (KCRP), 140 km from the middle of the area, began a volume at 10:45 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.

Severe Thunderstorm Watch 124May 3, 6:10 AM CDT

The nearest sounding before it

Brownsville Intl, TX (KBRO), launched 00:00Z, 10.8 hours before the alert went out and 145 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: 2441 J/kg
Mixed-layer CIN: -101 J/kg
Mixed-layer LCL: 740 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: 73 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

135 
ACUS11 KWNS 031045
SWOMCD
SPC MCD 031045 
TXZ000-031145-

Mesoscale Discussion 0511
NWS Storm Prediction Center Norman OK
0545 AM CDT Fri May 03 2019

Areas affected...Deep South TX

Concerning...Severe potential...Watch possible 

Valid 031045Z - 031145Z

Probability of Watch Issuance...60 percent

SUMMARY...The potential for organized severe thunderstorms appears
to be increasing early this morning in the Lower Rio Grande Valley. 
A severe thunderstorm watch may be needed soon if 1) intensification
continues and/or 2) the movement of storms is southeast rather than
south-southeast west of the Rio Grande.

DISCUSSION...Radar imagery shows a bowing MCS with a pair of intense
updrafts near Laredo as of 540am CDT.  The airmass over Deep South
TX is characterized as very moist with surface dewpoints in the
lower 70s degrees F and MLCAPE around 2500 J/kg.  Although upper-air
forcing for ascent will likely remain fairly weak, effective shear
around 40kt supports severe storm organization.  The primary threats
with this activity are isolated severe gusts and large to perhaps
localized very large hail if supercellular structure can be maintain
on the west flank of the organizing thunderstorm cluster.

..Smith/Edwards.. 05/03/2019

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

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

LAT...LON   26399916 27469959 27689932 27499836 27469735 26609744
            25929729 25999820 26399916

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 2, 10:26 PM CDT	Mesoscale Discussion	SPC	Brewster, Dimmit, Kinney, Maverick, Terrell, Val Verde and 2 more	2 hr
May 3, 6:13 AM CDT	Severe Thunderstorm Watch	SPC	Brooks, Cameron, Duval, Hidalgo, Jim Hogg, Jim Wells and 8 more	5 hr
May 3, 7:39 AM CDT	Mesoscale Discussion	SPC	Colorado, DeWitt, Fayette, Lavaca	66 min
May 3, 9:59 AM CDT	Mesoscale Discussion	SPC	Brooks, Cameron, Duval, Hidalgo, Jim Wells, Kenedy and 4 more	16 min
May 3, 12:20 PM CDT	Mesoscale Discussion	SPC	Fort Bend, Harris, Waller	2 hr
May 3, 1:26 PM CDT	Mesoscale Discussion	SPC	Andrews, Bailey, Brewster, Cochran, Crane, Dawson and 15 more	3 hr
May 3, 3:26 PM CDT	Severe Thunderstorm Watch	SPC	Andrews, Bailey, Borden, Brewster, Castro, Cochran and 25 more	6 hr
May 3, 4:23 PM CDT	Mesoscale Discussion	SPC	Atascosa, Bandera, Bexar, Blanco, Comal, Dimmit and 16 more	67 min
May 3, 4:35 PM CDT	Severe Thunderstorm Watch	SPC	Atascosa, Bandera, Bastrop, Bexar, Blanco, Burnet and 31 more	6 hr
May 3, 5:58 PM CDT	Mesoscale Discussion	SPC	Andrews, Bailey, Cochran, Crane, Dawson, Ector and 10 more	92 min
May 3, 6:48 PM CDT	Mesoscale Discussion	SPC	Atascosa, Bandera, Bastrop, Bexar, Blanco, Caldwell and 16 more	57 min

Nearby

Mesoscale Discussions in Texas, 2019 Every mesoscale discussion in 2019

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.