Alert archive / Texas / Mesoscale Discussions in 2012
Mesoscale Discussion 273
The Storm Prediction Center issued this mesoscale discussion at Mar 18, 2012, 2:31 PM CDT for 9 counties in Oklahoma; 33 counties in Texas. It was in force for 119 min.
The area
The outline as issued.
The facts
- Issued
- Mar 18, 2012, 2:31 PM CDT (19:31 UTC)
- Expired
- Mar 18, 2012, 4:30 PM CDT
- In force
- 119 min
- Issued by
- the Storm Prediction Center
All 42 counties
Beaver County, OK, Beckham County, OK, Ellis County, OK, Greer County, OK, Harmon County, OK, Harper County, OK, Jackson County, OK, Roger Mills County, OK, Woodward County, OK, Armstrong County, TX, Borden County, TX, Briscoe County, TX, Carson County, TX, Childress County, TX, Collingsworth County, TX, Cottle County, TX, Crosby County, TX, Dickens County, TX, Donley County, TX, Fisher County, TX, Floyd County, TX, Foard County, TX, Garza County, TX, Gray County, TX, Hall County, TX, Hansford County, TX, Hardeman County, TX, Haskell County, TX, Hemphill County, TX, Hutchinson County, TX, Jones County, TX, Kent County, TX, King County, TX, Knox County, TX, Lipscomb County, TX, Motley County, TX, Ochiltree County, TX, Roberts County, TX, Scurry County, TX, Stonewall County, TX, Wheeler County, TX, Wilbarger County, TX
The radar
The Amarillo radar (KAMA), 134 km from the middle of the area, began a volume at 19:32 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, 7.5 hours before the alert went out and 133 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
- 1066 J/kg
- Mixed-layer CIN
- -188 J/kg
- Mixed-layer LCL
- 832 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 123 m²/s²
- 0-3 km storm-relative helicity
- 75 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.7
The text
As transmitted, in the capitals the NWS used until 2016.
970
ACUS11 KWNS 181931
SWOMCD
SPC MCD 181931
OKZ000-TXZ000-KSZ000-182130-
MESOSCALE DISCUSSION 0273
NWS STORM PREDICTION CENTER NORMAN OK
0231 PM CDT SUN MAR 18 2012
AREAS AFFECTED...ERN OK/TX PANHANDLES...FAR WRN OK...WRN N TX
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY
VALID 181931Z - 182130Z
THE SEVERE THREAT WILL INCREASE OVER THE NEXT 1-3 HOURS AND
THUNDERSTORMS ARE EXPECTED TO INITIATE AROUND 21Z. LARGE HAIL WILL
BE THE MAIN THREAT BUT A FEW TORNADOES WILL ALSO BE POSSIBLE. A WW
WILL LIKELY BE NEEDED WITHIN THE NEXT HOUR OR SO.
19Z VIS SAT IMAGERY SHOWED CUMULUS BEGINNING TO DEVELOP ACROSS THE
TX S PLAINS E OF LBB AHEAD OF A DRYLINE EXTENDING SWD FROM WRN KS
THROUGH SWRN TX. AS TEMPERATURES HAVE WARMED INTO THE MID AND UPPER
70S THIS AFTERNOON...ONLY WEAK MLCIN REMAINS WITH MLCAPE VALUES NOW
APPROACHING 2000 J/KG. WITH ADDITIONAL HEATING REMAINING CAP WILL
QUICKLY ERODE AND CONVECTIVE INITIATION IS EXPECTED WITHIN THE NEXT
COUPLE OF HOURS. WHILE THE MAIN UPPER LEVEL FORCING REMAINS WELL TO
THE WEST ACROSS AZ/NM WITH THE UPPER LEVEL TROUGH...HEIGHT FALLS
HAVE BEEN OCCURRING ACROSS THE REGION THIS AFTERNOON AND RECENT
PROFILER DATA HAVE INDICATED AN INCREASE IN MIDLEVEL FLOW STREAMING
INTO THE MCD AREA. GIVEN BULK SHEAR VALUES OF 35-45 KTS AND MIDLEVEL
LAPSE RATES AROUND 7.5 DEG C/KM...ORGANIZED SUPERCELL STORMS CAPABLE
OF LARGE HAIL ARE EXPECTED. WHILE LARGE HAIL WILL INITIALLY BE THE
MAIN THE THREAT...AS THE UPPER TROUGH MOVES EWD AND STRONGER DEEP
LAYER FORCING ENCROACHES UPON THE REGION TOWARD 00Z...LOW LEVEL
HODOGRAPHS WILL BECOME MORE FAVORABLE FOR TORNADO DEVELOPMENT.
THEREFORE...A TORNADO WATCH WILL LIKELY BE ISSUED.
..LEITMAN.. 03/18/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...OUN...DDC...SJT...LUB...AMA...MAF...
LAT...LON 37020094 36780133 35050158 33850158 32570148 32430135
32330051 32399977 32519954 34379914 35069913 36689918
36989953 37020094SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 18, 3:12 PM CDT | Tornado Watch | SPC | Beaver, Beckham, Custer, Dewey, Ellis, Greer and 8 more | 7 hr |
| Mar 18, 5:36 PM CDT | Mesoscale Discussion | SPC | Beaver, Beckham, Ellis, Greer, Harmon, Jackson and 1 more | 84 min |
Nearby
Mesoscale Discussions in Texas, 2012Mesoscale Discussions in Oklahoma, 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.