Alert archive / Texas / Mesoscale Discussions in 2012
Mesoscale Discussion 490
The Storm Prediction Center issued this mesoscale discussion at Apr 11, 2012, 2:05 PM MDT for 4 states. It was in force for 25 min.
The area
The outline as issued.
The facts
- Issued
- Apr 11, 2012, 2:05 PM MDT (20:05 UTC)
- Expired
- Apr 11, 2012, 2:30 PM MDT
- In force
- 25 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch possible
All 22 counties
Las Animas County, CO, Union County, NM, Cimarron County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Armstrong County, TX, Carson County, TX, Childress County, TX, Collingsworth County, TX, Dallam County, TX, Donley County, TX, Gray County, TX, Hall County, TX, Hansford County, TX, Hartley County, TX, Hutchinson County, TX, Moore County, TX, Potter County, TX, Roberts County, TX, Sherman County, TX, Wheeler County, TX
The radar
The Amarillo radar (KAMA), 59 km from the middle of the area, began a volume at 20:07 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
Amarillo Airport, TX (KAMA), launched 12:00Z, 8.1 hours before the alert went out and 59 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
- 676 J/kg
- Mixed-layer CIN
- -107 J/kg
- Mixed-layer LCL
- 1126 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 91 m²/s²
- 0-3 km storm-relative helicity
- 135 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.6
The text
As transmitted, in the capitals the NWS used until 2016.
482
ACUS11 KWNS 112005
SWOMCD
SPC MCD 112005 COR
OKZ000-TXZ000-COZ000-NMZ000-112030-
MESOSCALE DISCUSSION 0490
NWS STORM PREDICTION CENTER NORMAN OK
0305 PM CDT WED APR 11 2012
AREAS AFFECTED...SERN CO INTO THE TX PANHANDLE
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 112005Z - 112030Z
CORRECTED FOR GRAPHICAL ERROR
COVERAGE OF THUNDERSTORMS CONTINUES TO INCREASE ACROSS SERN CO INTO
THE TX PANHANDLE. ALTHOUGH LARGE HAIL AND DMGG WINDS WILL BE THE
PREDOMINANT THREAT...AN ISOLATED TORNADO CANNOT BE RULED OUT. A WW
MAY BE NEEDED THIS AFTERNOON.
THE EARLIER STRATUS LAYER HAS ERODED...WITH AMPLE SUNSHINE
SUPPORTING A GRADUAL EROSION OF CONVECTIVE INHIBITION ACROSS A
GENERALLY MOIST AND UNSTABLE AIR MASS. A RECENT INCREASE IN VERTICAL
DEVELOPMENT OF CUMULUS HAS BEEN NOTED ON VARIOUS 1915Z SATELLITE
IMAGES AND SUPPORTING RADAR IMAGERY. SEVERAL SURFACE
BOUNDARIES/AREAS OF CONVERGENCE ARE SUPPORTING AN INCREASE IN
CONVECTIVE DEVELOPMENT...WITH UPSLOPE WINDS CLOSER TO THE HIGHER
TERRAIN...A STATIONARY FRONT ACROSS THE PANHANDLE THAT HAS BEEN
REINFORCED BY DIFFERENTIAL HEATING...AND A SUBTLE OUTFLOW BOUNDARY
ACROSS THE PANHANDLE AS WELL. SEVERAL SMALLER UPPER DISTURBANCES ARE
LIKELY BOLSTERING THIS CONVECTION. HOWEVER...WITH THE LARGER SCALE
RIDGE OVER THE AREA...STORMS HAVE CURRENTLY BEEN SLOW TO BECOME
SEVERE WITH LARGE SCALE SUBSIDENCE AND WEAK MID-UPPER LEVEL SHEAR.
WITH TIME...DEEP LAYER WINDS WILL STRENGTHEN WITH THE APPROACH OF AN
UPPER TROUGH...WITH STRENGTHENING IN LOW-LEVEL SELYS AS WELL. AS A
RESULT...ROTATING STORMS MAY BECOME INCREASINGLY POSSIBLE LATER
TODAY.
..HURLBUT.. 04/11/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...OUN...LUB...AMA...PUB...ABQ...
LAT...LON 34270016 34960173 35650308 36810401 37610457 37730376
36660175 35840051 35079943 34509939 34270016SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 11, 1:05 PM MDT | Mesoscale Discussion | SPC | Alamosa, Conejos, Costilla, Custer, Fremont, Huerfano and 3 more | 115 min |
| Apr 11, 2:11 PM MDT | Tornado Watch | SPC | Baca, Bent, Las Animas, Otero, Prowers | 7 hr |
| Apr 11, 5:08 PM MDT | Mesoscale Discussion | SPC | Baca | 97 min |
| Apr 11, 1:53 PM MDT | Mesoscale Discussion | SPC | Eddy, Otero | 97 min |
| Apr 11, 2:43 PM MDT | Severe Thunderstorm Watch | SPC | Chaves, Colfax, Curry, De Baca, Eddy, Guadalupe and 6 more | 6 hr |
| Apr 11, 5:21 PM MDT | Mesoscale Discussion | SPC | Chaves, Curry, De Baca, Eddy, Guadalupe, Harding and 5 more | 84 min |
Nearby
Mesoscale Discussions in Texas, 2012Mesoscale Discussions in Oklahoma, 2012Mesoscale Discussions in Colorado, 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.