Alert archive / Texas / Mesoscale Discussions in 2012
Mesoscale Discussion 302
The Storm Prediction Center issued this mesoscale discussion at Mar 20, 2012, 2:43 AM CDT for 19 counties in Texas. It was in force for 92 min.
The area
The outline as issued.
The facts
- Issued
- Mar 20, 2012, 2:43 AM CDT (07:43 UTC)
- Expired
- Mar 20, 2012, 4:15 AM CDT
- In force
- 92 min
- Issued by
- the Storm Prediction Center
Counties Aransas County, TX, Bee County, TX, Calhoun County, TX, Colorado County, TX, DeWitt County, TX, Duval County, TX, Fort Bend County, TX, Goliad County, TX, Jackson County, TX, Jim Wells County, TX, Karnes County, TX, Lavaca County, TX, Live Oak County, TX, Matagorda County, TX, Nueces County, TX, Refugio County, TX, San Patricio County, TX, Victoria County, TX, Wharton County, TX
The radar
The Corpus Christi radar (KCRP), 67 km from the middle of the area, began a volume at 07:45 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 nearest sounding before it
Corpus Christi, TX (KCRP), launched 00:00Z, 7.7 hours before the alert went out and 77 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.
- Mixed-layer CAPE
- 2851 J/kg
- Mixed-layer CIN
- -113 J/kg
- Mixed-layer LCL
- 778 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 121 m²/s²
- 0-3 km storm-relative helicity
- 88 m²/s²
- Significant tornado parameter
- 0.6
- Supercell composite
- 3.0
The text
As transmitted, in the capitals the NWS used until 2016.
778
ACUS11 KWNS 200743
SWOMCD
SPC MCD 200743
TXZ000-200915-
MESOSCALE DISCUSSION 0302
NWS STORM PREDICTION CENTER NORMAN OK
0243 AM CDT TUE MAR 20 2012
AREAS AFFECTED...PARTS OF S CNTRL TX INTO MID/UPPER TEXAS COASTAL
AREAS
CONCERNING...SEVERE THUNDERSTORM WATCH 91...
VALID 200743Z - 200915Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 91
CONTINUES.
CONVECTION ON THE SOUTHERN FLANK OF A MORE EXTENSIVE SQUALL LINE
APPEARS TO BE INTENSIFYING AND SHOWING SIGNS OF INCREASING
ORGANIZATION TO THE SOUTH AND SOUTHEAST OF SAN ANTONIO. HEAVY
PRECIPITATION LOADING AND EVAPORATIVE COOLING IN DOWNDRAFTS APPEAR
TO BE CONTRIBUTING TO THE DEVELOPMENT OF A SIGNIFICANT SURFACE COLD
POOL...WHICH APPEARS TO BE IN THE PROCESS OF SURGING EASTWARD AT UP
TO 40 KT. THE RISK FOR STRONG...POTENTIAL DAMAGING...WIND GUSTS
APPEARS TO BE INCREASING AS ACTIVITY SPREADS EAST NORTHEASTWARD INTO
VICTORIA AND ADJACENT MIDDLE TEXAS COASTAL AREAS THROUGH THE 09-11Z
TIME FRAME. IT DOES NOT SEEM OUT OF THE QUESTION THAT NORTHWARD
INTENSIFICATION OF ACTIVITY COULD OCCUR INTO AT LEAST SOUTHERN
PORTIONS OF THE HOUSTON METROPOLITAN AREA SHORTLY THEREAFTER.
THERE ALSO APPEARS AT LEAST SOME POTENTIAL FOR ISOLATED SUPERCELL
DEVELOPMENT JUST AHEAD OF THE EASTWARD ADVANCING COLD POOL...IN THE
PRESENCE OF MODERATELY LARGE BOUNDARY LAYER CAPE...AND STRONG
LOW-LEVEL SHEAR BENEATH A 50-70 KT SOUTHERLY 850 MB JET. IF THIS
OCCURS...A RISK FOR TORNADOES MAY ALSO DEVELOP.
..KERR.. 03/20/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...HGX...CRP...EWX...BRO...
LAT...LON 27829913 28429837 28739810 29649689 29719570 29639527
28779562 28029680 27439781 27289884 27369927 27829913SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 19, 7:28 PM CDT | Tornado Watch | SPC | Anderson, Bell, Bowie, Camp, Cass, Cherokee and 30 more | 9 hr |
| Mar 19, 8:22 PM CDT | Mesoscale Discussion | SPC | Bandera, Bell, Bexar, Blanco, Burnet, Comal and 30 more | 53 min |
| Mar 19, 9:46 PM CDT | Mesoscale Discussion | SPC | Bandera, Bell, Blanco, Burnet, Coryell, Ellis and 18 more | 119 min |
| Mar 19, 11:53 PM CDT | Mesoscale Discussion | SPC | Atascosa, Bastrop, Bell, Bexar, Burleson, Caldwell and 28 more | 67 min |
| Mar 20, 12:48 AM CDT | Severe Thunderstorm Watch | SPC | Aransas, Atascosa, Austin, Bastrop, Bee, Bexar and 52 more | 9 hr |
| Mar 20, 5:26 AM CDT | Mesoscale Discussion | SPC | Brazoria, Calhoun, Fort Bend, Harris, Liberty, Matagorda and 3 more | 2 hr |
| Mar 20, 9:03 AM CDT | Mesoscale Discussion | SPC | Chambers, Galveston, Hardin, Jasper, Jefferson, Liberty and 6 more | 87 min |
| Mar 20, 9:46 AM CDT | Tornado Watch | SPC | Hardin, Jasper, Jefferson, Newton, Orange, Sabine and 3 more | 7 hr |
Nearby
Mesoscale Discussions in Texas, 2012Every mesoscale discussion in 2012
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.