Alert archive / Texas / Mesoscale Discussions in 2012
Mesoscale Discussion 746
The Storm Prediction Center issued this mesoscale discussion at May 7, 2012, 2:37 PM CDT for 17 counties in Texas. It was in force for 83 min.
The area
The outline as issued.
The facts
- Issued
- May 7, 2012, 2:37 PM CDT (19:37 UTC)
- Expired
- May 7, 2012, 4:00 PM CDT
- In force
- 83 min
- Issued by
- the Storm Prediction Center
Counties Bandera County, TX, Blanco County, TX, Burnet County, TX, Concho County, TX, Gillespie County, TX, Kendall County, TX, Kerr County, TX, Kimble County, TX, Lampasas County, TX, Llano County, TX, Mason County, TX, McCulloch County, TX, Menard County, TX, Mills County, TX, San Saba County, TX, Schleicher County, TX, Tom Green County, TX
The radar
The San Angelo radar (KSJT), 124 km from the middle of the area, began a volume at 19:40 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
Del Rio, TX (KDRT), launched 12:00Z, 7.6 hours before the alert went out and 210 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
- 3104 J/kg
- Mixed-layer CIN
- -170 J/kg
- Mixed-layer LCL
- 1000 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 122 m²/s²
- 0-3 km storm-relative helicity
- 68 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
531
ACUS11 KWNS 071937
SWOMCD
SPC MCD 071937
TXZ000-072100-
MESOSCALE DISCUSSION 0746
NWS STORM PREDICTION CENTER NORMAN OK
0237 PM CDT MON MAY 07 2012
AREAS AFFECTED...EDWARDS PLATEAU INTO THE TEXAS HILL COUNTRY
CONCERNING...SEVERE THUNDERSTORM WATCH 261...
VALID 071937Z - 072100Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 261
CONTINUES.
SUMMARY...UPSCALE CONVECTIVE GROWTH INTO FORWARD /EASTWARD/
PROPAGATING SEVERE MESOSCALE CONVECTIVE SYSTEM APPEARS LIKELY DURING
THE NEXT FEW HOURS. THIS COULD SPREAD ACROSS THE TEXAS HILL COUNTRY
INTO THE I-35 CORRIDOR OF SOUTH CENTRAL TEXAS BY 23-00Z. AN
ADDITIONAL WW EAST OF 261 PROBABLY WILL BECOME NECESSARY WITHIN THE
NEXT HOUR OR TWO.
DISCUSSION...INTENSE CONVECTIVE DEVELOPMENT CONTINUES TO INCREASE IN
THE PRESENCE OF STRONG CONVECTIVE INSTABILITY AND LARGE
CAPE...FOCUSED NEAR/NORTH OF A PERSISTENT ZONE OF ENHANCED
CONVERGENCE ACROSS THE EDWARDS PLATEAU. FLOW IN THE LOWER/MID
TROPOSPHERE IS GENERALLY LIGHT...BUT...ALOFT...40-50+ KT WEST
SOUTHWESTERLY WIND FIELDS APPEAR TO BE CONTRIBUTING TO AT LEAST 20
KT OR SO OF WESTERLY MEAN CONVECTIVE LAYER FLOW. DURING THE NEXT
FEW HOURS...THIS SEEMS LIKELY TO CONTRIBUTE TO THE EVENTUAL EASTWARD
ACCELERATION OF CONVECTIVE ACTIVITY...WHICH SHOULD CONTINUE TO GROW
UPSCALE INTO AN INCREASINGLY ORGANIZED MESOSCALE CONVECTIVE SYSTEM
AS CONVECTIVELY GENERATED COLD POOLS CONSOLIDATE. AS THIS
OCCURS...A BROADER SCALE DAMAGING WIND THREAT MAY BECOME MORE
PROMINENT... WITH ACTIVITY SPREADING ACROSS THE TEXAS HILL
COUNTRY...AND PERHAPS APPROACHING THE WACO/TEMPLE/AUSTIN AND SAN
ANTONIO AREAS BY 23-00Z.
..KERR.. 05/07/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...FWD...EWX...SJT...
LAT...LON 31200086 31590029 31759879 31539805 31099768 30449799
29739830 29629918 30029988 30560026 30660050 31200086SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 7, 12:46 PM CDT | Severe Thunderstorm Watch | SPC | Brewster, Brown, Callahan, Coke, Coleman, Concho and 23 more | 8 hr |
| May 7, 2:24 PM CDT | Mesoscale Discussion | SPC | Andrews, Crane, Ector, Gaines, Loving, Midland and 3 more | 2 hr |
| May 7, 3:27 PM CDT | Severe Thunderstorm Watch | SPC | Bandera, Bastrop, Bell, Bexar, Blanco, Bosque and 30 more | 7 hr |
| May 7, 3:56 PM CDT | Severe Thunderstorm Watch | SPC | Andrews, Culberson, Ector, Gaines, Jeff Davis, Loving and 4 more | 7 hr |
| May 7, 4:38 PM CDT | Mesoscale Discussion | SPC | Bowie, Camp, Cass, Franklin, Gregg, Harrison and 4 more | 67 min |
| May 7, 5:21 PM CDT | Severe Thunderstorm Watch | SPC | Bowie, Cass | 5 hr |
| May 7, 5:31 PM CDT | Mesoscale Discussion | SPC | Bandera, Bastrop, Bell, Blanco, Burnet, Comal and 28 more | 89 min |
| May 7, 6:55 PM CDT | Mesoscale Discussion | SPC | Andrews, Borden, Crane, Dawson, Ector, Gaines and 11 more | 95 min |
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.