Alert archive / Texas / Mesoscale Discussions in 2012
Mesoscale Discussion 67
The Storm Prediction Center issued this mesoscale discussion at Jan 25, 2012, 7:13 AM CST for 46 counties in Texas. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jan 25, 2012, 7:13 AM CST (13:13 UTC)
- Expired
- Jan 25, 2012, 9:15 AM CST
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 46 counties
Anderson County, TX, Angelina County, TX, Aransas County, TX, Austin County, TX, Bee County, TX, Brazoria County, TX, Brazos County, TX, Burleson County, TX, Calhoun County, TX, Chambers County, TX, Cherokee County, TX, Colorado County, TX, DeWitt County, TX, Fayette County, TX, Fort Bend County, TX, Freestone County, TX, Galveston County, TX, Goliad County, TX, Gonzales County, TX, Grimes County, TX, Harris County, TX, Henderson County, TX, Houston County, TX, Jackson County, TX, Jim Wells County, TX, Kleberg County, TX, Lavaca County, TX, Leon County, TX, Liberty County, TX, Limestone County, TX, Madison County, TX, Matagorda County, TX, Montgomery County, TX, Navarro County, TX, Nueces County, TX, Polk County, TX, Refugio County, TX, Robertson County, TX, San Jacinto County, TX, San Patricio County, TX, Trinity County, TX, Victoria County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Wharton County, TX
The radar
The Houston radar (KHGX), 117 km from the middle of the area, began a volume at 13:12 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
Corpus Christi, TX (KCRP), launched 12:00Z, 1.2 hours before the alert went out and 222 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
- 1968 J/kg
- Mixed-layer CIN
- -2 J/kg
- Mixed-layer LCL
- 518 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 280 m²/s²
- 0-3 km storm-relative helicity
- 344 m²/s²
- Significant tornado parameter
- 3.5
- Supercell composite
- 21.9
The text
As transmitted, in the capitals the NWS used until 2016.
776
ACUS11 KWNS 251313
SWOMCD
SPC MCD 251313
TXZ000-251515-
MESOSCALE DISCUSSION 0067
NWS STORM PREDICTION CENTER NORMAN OK
0713 AM CST WED JAN 25 2012
AREAS AFFECTED...PORTIONS S-CENTRAL/SE/E-CENTRAL TX.
CONCERNING...TORNADO WATCH 14...
VALID 251313Z - 251515Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 14 CONTINUES.
ADDED COUNTIES OR NEW WW MAY BE NEEDED E OF PRESENT WW
CONFIGURATION...BEFORE SCHEDULED 17Z EXPIRATION.
CONTINUE WW ALONG AND E OF PRIMARY SQUALL LINE...EVIDENT AT 1245Z IN
TWO NEARLY CONNECTED SEGMENTS FROM LIMESTONE-DEWITT COUNTIES...AND
FROM CALDWELL-JIM WELLS COUNTIES. IN ADDITION TO TRANSLATIONAL EWD
MOTION...PRIMARY MCS IS DISCRETELY PROPAGATING EWD...IN STEPWISE
FASHION AS NEW CONVERGENCE/CONVECTIVE BANDS DEVELOP. THIS PROCESS
WILL RESULT IN EARLIER ARRIVAL OF SQUALL LINE THAN PURE
EXTRAPOLATION INDICATES...AND POTENTIAL ONSET OF SVR THREAT OVER
E-CENTRAL/SE BEFORE 17Z.
MODIFIED 12 CRP RAOB AND RUC SOUNDINGS SUGGEST DEEP LAYER OF RICH
LOW-LEVEL MOISTURE AVAILABLE TO THIS ACTIVITY--I.E. 90-100% RH
THROUGH SFC-750-MB LAYER...PW 1.25-1.5 INCHES...AND MLCAPE RANGING
FROM OVER 2000 J/KG THERE TO AROUND 500 J/KG BETWEEN CLL-PSN.
MLCINH INCREASES SWWD BENEATH PROGRESSIVELY STRONGER EML...AND EWD
ACROSS SE TX INTO LA GIVEN MORE STABLE AIR IN AND N OF WARM FRONTAL
ZONE. SFC MESOANALYSIS SHOWED WARM FRONT EXTENDING FROM NRN FRINGES
OF SQUALL LINE SEWD ACROSS JASPER COUNTY TO NEAR CENTRAL PORTIONS LA
COAST. FRONT WILL MOVE NEWD 5-10 KT...OVERTAKEN FROM NW-SE BY
SQUALL LINE THROUGHOUT MORNING. THIS WILL RESULT IN NET SLOW EWD
SHIFT...BUT ALSO COASTWARD CONTRACTION...OF WARM SECTOR WITH TIME.
LDB PROFILER AND HGX VWP INDICATE 400-500 J/KG 0-1 KM
SRH...SUPPORTING STORM-SCALE ROTATION EITHER IN EMBEDDED SQUALL-LINE
MESOCIRCULATIONS OR IN ANY SUPERCELLULAR ELEMENTS THAT CAN FORM
AHEAD OF MAIN MCS.
..EDWARDS.. 01/25/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LCH...SHV...HGX...FWD...CRP...EWX...BRO...
LAT...LON 27299834 28579778 29729768 29759711 30639676 31229676
32279649 32259547 31829473 30859445 30199451 29499448
29409470 29289476 28649581 28449622 28039683 27549721
27279737 27299834SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 24, 7:13 PM CST | Mesoscale Discussion | SPC | Atascosa, Bandera, Bastrop, Bexar, Blanco, Caldwell and 23 more | 92 min |
| Jan 24, 10:05 PM CST | Tornado Watch | SPC | Atascosa, Bandera, Bastrop, Bee, Bexar, Blanco and 33 more | 5 hr |
| Jan 24, 11:34 PM CST | Mesoscale Discussion | SPC | Atascosa, Bandera, Bastrop, Bee, Bexar, Blanco and 38 more | 56 min |
| Jan 25, 2:12 AM CST | Mesoscale Discussion | SPC | Atascosa, Austin, Bandera, Bastrop, Bee, Bell and 56 more | 2 hr |
| Jan 25, 3:17 AM CST | Tornado Watch | SPC | Anderson, Aransas, Atascosa, Austin, Bastrop, Bee and 67 more | 11 hr |
| Jan 25, 7:56 AM CST | Tornado Watch | SPC | Angelina, Cherokee, Hardin, Jasper, Jefferson, Nacogdoches and 8 more | 7 hr |
| Jan 25, 10:09 AM CST | Mesoscale Discussion | SPC | Brazoria, Chambers, Fort Bend, Harris, Liberty, Matagorda and 5 more | 96 min |
| Jan 25, 11:24 AM CST | Mesoscale Discussion | SPC | Brazoria, Chambers, Galveston, Hardin, Harrison, Jasper and 10 more | 2 hr |
| Jan 25, 2:08 PM CST | Tornado Watch | SPC | Jefferson, Orange | 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.