Alert archive / Texas / Mesoscale Discussions in 2012
Mesoscale Discussion 696
The Storm Prediction Center issued this mesoscale discussion at May 4, 2012, 2:50 PM CDT for 6 counties in Oklahoma; 28 counties in Texas. It was in force for 85 min.
The area
The outline as issued.
The facts
- Issued
- May 4, 2012, 2:50 PM CDT (19:50 UTC)
- Expired
- May 4, 2012, 4:15 PM CDT
- In force
- 85 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 60%
All 34 counties
Comanche County, OK, Cotton County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Tillman County, OK, Archer County, TX, Baylor County, TX, Brown County, TX, Callahan County, TX, Clay County, TX, Coleman County, TX, Concho County, TX, Crockett County, TX, Eastland County, TX, Foard County, TX, Hardeman County, TX, Haskell County, TX, Irion County, TX, Jack County, TX, Jones County, TX, Knox County, TX, Palo Pinto County, TX, Runnels County, TX, Schleicher County, TX, Shackelford County, TX, Stephens County, TX, Sutton County, TX, Taylor County, TX, Throckmorton County, TX, Tom Green County, TX, Wichita County, TX, Wilbarger County, TX, Young County, TX
The radar
The Dyess AFB radar (KDYX), 100 km from the middle of the area, began a volume at 19:53 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
Midland Regional, TX (KMAF), launched 12:00Z, 7.8 hours before the alert went out and 185 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
- 378 J/kg
- Mixed-layer CIN
- -346 J/kg
- Mixed-layer LCL
- 2819 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 47 m²/s²
- 0-3 km storm-relative helicity
- 65 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
056
ACUS11 KWNS 041950
SWOMCD
SPC MCD 041950
TXZ000-OKZ000-042115-
MESOSCALE DISCUSSION 0696
NWS STORM PREDICTION CENTER NORMAN OK
0250 PM CDT FRI MAY 04 2012
AREAS AFFECTED...SWRN OK TO SWRN TX
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 041950Z - 042115Z
PROBABILITY OF WATCH ISSUANCE...60 PERCENT
SUMMARY...ISOLATED SEVERE THUNDERSTORMS MAY DEVELOP ALONG THE
DRYLINE FROM SWRN OK...ARCING INTO SWRN TX OVER THE NEXT 1-3 HOURS.
LARGE HAIL AND STRONG-GUSTY WINDS ARE POSSIBLE.
DISCUSSION...LATEST WV IMAGERY DEPICTS AN EJECTING UPPER VORT OVER
SWRN OK AND EARLIER MID LEVEL CONVECTION/DEBRIS HAS GRADUALLY
DISSIPATED INVOF THIS FEATURE. AS A RESULT...STRONG LOW LEVEL
HEATING HAS CONTRIBUTED TO A DEEPENING BOUNDARY LAYER ALONG THE
DRYLINE FROM SWRN OK INTO SWRN TX. IT APPEARS CONVECTIVE
TEMPERATURES HAVE BEEN BREACHED ALONG THIS ZONE PER RECENT CU
DEVELOPMENT AS READINGS HAVE SOARED INTO THE UPPER 90S. FORECAST
SOUNDINGS SUGGEST DRYLINE CONVECTION WILL HAVE BASES ABOVE 700MB
WITH SBCAPE ON THE ORDER OF 1500-2000 J/KG. WITH A POCKET OF COLD
MID LEVEL TEMPERATURES...H5 OF MINUS 12-14C...IT WOULD SEEM LIKELY
THAT ANY HIGH BASED THUNDERSTORMS SHOULD PRODUCE HAIL IN ADDITION TO
POTENTIALLY DAMAGING DOWNBURSTS. IN THE ABSENCE OF STRONG LARGE
SCALE SUPPORT STORMS SHOULD REMAIN ISOLATED AS THEY DRIFT EAST AT
ROUGHLY 10-15KT.
..DARROW/MEAD.. 05/04/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...FWD...OUN...EWX...SJT...LUB...MAF...
LAT...LON 30600251 31660056 33519977 35039993 34709799 32639784
29830120 30600251SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 4, 3:49 PM CDT | Severe Thunderstorm Watch | SPC | Carter, Comanche, Cotton, Jackson, Jefferson, Love and 3 more | 7 hr |
| May 4, 5:30 PM CDT | Mesoscale Discussion | SPC | Cotton, Tillman | 60 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.