Alert archive / Texas / Mesoscale Discussions in 2004

Mesoscale Discussion 548

May 1, 2004Willacy County, Texas

The Storm Prediction Center issued this mesoscale discussion at May 1, 2004, 1:14 PM CDT for Willacy County, Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 1, 2004, 1:14 PM CDT (18:14 UTC)
Expired: May 1, 2004, 3:15 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

County Willacy County, TX

The radar

The Brownsville radar (KBRO), 61 km from the middle of the area, began a volume at 18:16 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

Brownsville Intl, TX (KBRO), launched 12:00Z, 6.2 hours before the alert went out and 64 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: 1935 J/kg
Mixed-layer CIN: -157 J/kg
Mixed-layer LCL: 826 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 112 m²/s²
0-3 km storm-relative helicity: 156 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

948 
ACUS11 KWNS 011814
SWOMCD
SPC MCD 011814 
TXZ000-012015-

MESOSCALE DISCUSSION 0548
NWS STORM PREDICTION CENTER NORMAN OK
0114 PM CDT SAT MAY 01 2004

AREAS AFFECTED...DEEP SOUTH TEXAS

CONCERNING...SEVERE THUNDERSTORM WATCH 144...

VALID 011814Z - 012015Z

WW WILL LIKELY BE ALLOWED TO EXPIRE AS SCHEDULED AT 20Z.

SLOW EASTWARD PROGRESSION OF LARGE-SCALE UPPER TROUGH ACROSS THE
SOUTHERN PLAINS CONTINUES.  STRONGLY DIFLUENT/DIVERGENT UPPER FLOW
FIELD AHEAD OF BASE OF THIS TROUGH WILL SOON BEGIN TO SHIFT OUT OF
DEEP SOUTH TEXAS INTO THE WESTERN GULF OF MEXICO.  STRONGER
LOW-LEVEL CONVERGENCE IS ALREADY BECOMING FOCUSED WELL TO THE SOUTH
OF THE RIO GRANDE RIVER...ACROSS NORTHWESTERN TAMAULIPAS.  AS
LARGE-SCALE ASCENT DIMINISHES...CONVECTIVE POTENTIAL IS EXPECTED TO
DECREASE AS WELL.

..KERR.. 05/01/2004

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

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

26039807 26539784 26669746 26649732

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 30, 7:00 PM CDT	Mesoscale Discussion	SPC	Bosque, Brown, Coleman, Comanche, Concho, Eastland and 11 more	90 min
Apr 30, 7:22 PM CDT	Mesoscale Discussion	SPC	Anderson, Bowie, Camp, Cass, Cherokee, Delta and 25 more	83 min
Apr 30, 7:40 PM CDT	Severe Thunderstorm Watch	SPC	Anderson, Bowie, Camp, Delta, Ellis, Fannin and 20 more	5 hr
Apr 30, 8:14 PM CDT	Mesoscale Discussion	SPC	Archer, Clay, Collin, Cooke, Denton, Grayson and 8 more	91 min
Apr 30, 9:07 PM CDT	Mesoscale Discussion	SPC	Bosque, Brown, Comanche, Coryell, Erath, Hamilton and 8 more	53 min
Apr 30, 9:54 PM CDT	Mesoscale Discussion	SPC	Anderson, Bowie, Camp, Delta, Ellis, Franklin and 19 more	96 min
Apr 30, 10:34 PM CDT	Mesoscale Discussion	SPC	Brown, Coleman, Concho, Crockett, Edwards, Irion and 15 more	86 min
Apr 30, 11:35 PM CDT	Severe Thunderstorm Watch	SPC	Blanco, Concho, Crockett, Edwards, Gillespie, Irion and 13 more	5 hr
Apr 30, 11:56 PM CDT	Mesoscale Discussion	SPC	Chambers, Galveston, Grimes, Hardin, Harris, Jasper and 10 more	94 min
May 1, 12:50 AM CDT	Severe Thunderstorm Watch	SPC	Anderson, Bell, Bosque, Bowie, Camp, Cass and 47 more	6 hr
May 1, 1:34 AM CDT	Mesoscale Discussion	SPC	Atascosa, Bandera, Bexar, Blanco, Comal, Concho and 24 more	86 min
May 1, 1:49 AM CDT	Mesoscale Discussion	SPC	Anderson, Bell, Cherokee, Falls, Freestone, Henderson and 5 more	86 min
May 1, 2:38 AM CDT	Mesoscale Discussion	SPC	Angelina, Sabine, San Augustine, Shelby	37 min
May 1, 3:10 AM CDT	Severe Thunderstorm Watch	SPC	Angelina, Sabine, San Augustine, Shelby	6 hr
May 1, 3:28 AM CDT	Mesoscale Discussion	SPC	Atascosa, Bandera, Bexar, Blanco, Concho, Crockett and 23 more	92 min
May 1, 3:41 AM CDT	Mesoscale Discussion	SPC	Austin, Brazoria, Brazos, Burleson, Chambers, Colorado and 18 more	64 min
May 1, 3:50 AM CDT	Tornado Watch	SPC	Angelina, Austin, Bastrop, Brazos, Burleson, Chambers and 25 more	6 hr
May 1, 5:13 AM CDT	Mesoscale Discussion	SPC	Anderson, Cherokee, Harrison, Nacogdoches, Panola, Rusk and 1 more	92 min
May 1, 5:40 AM CDT	Severe Thunderstorm Watch	SPC	Atascosa, Bee, Bexar, Caldwell, DeWitt, Dimmit and 17 more	6 hr
May 1, 6:08 AM CDT	Mesoscale Discussion	SPC	Angelina, Austin, Brazos, Burleson, Chambers, Colorado and 24 more	97 min
May 1, 7:24 AM CDT	Mesoscale Discussion	SPC	Sabine, San Augustine, Shelby	96 min
May 1, 7:33 AM CDT	Mesoscale Discussion	SPC	Atascosa, Bee, Bexar, Caldwell, DeWitt, Dimmit and 16 more	87 min
May 1, 7:47 AM CDT	Mesoscale Discussion	SPC	Austin, Bastrop, Brazos, Burleson, Chambers, Colorado and 23 more	88 min
May 1, 9:16 AM CDT	Mesoscale Discussion	SPC	Brazoria, Chambers, Fort Bend, Galveston, Hardin, Harris and 3 more	59 min
May 1, 9:36 AM CDT	Mesoscale Discussion	SPC	Nueces	114 min
May 1, 9:45 AM CDT	Tornado Watch	SPC	Brazoria, Chambers, Fort Bend, Galveston, Hardin, Harris and 6 more	5 hr
May 1, 9:55 AM CDT	Severe Thunderstorm Watch	SPC	Brooks, Cameron, Hidalgo, Jim Hogg, Kenedy, Kleberg and 3 more	5 hr
May 1, 11:15 AM CDT	Mesoscale Discussion	SPC	Kenedy	2 hr

Nearby

Mesoscale Discussions in Texas, 2004 Every mesoscale discussion in 2004

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.