Alert archive / Texas / Mesoscale Discussions in 2012
Mesoscale Discussion 1787
The Storm Prediction Center issued this mesoscale discussion at Aug 18, 2012, 5:00 PM CDT for Cotton County, Jefferson County, Tillman County, Oklahoma; 36 counties in Texas. It was in force for 90 min.
The area
The outline as issued.
The facts
- Issued
- Aug 18, 2012, 5:00 PM CDT (22:00 UTC)
- Expired
- Aug 18, 2012, 6:30 PM CDT
- In force
- 90 min
- Issued by
- the Storm Prediction Center
All 39 counties
Cotton County, OK, Jefferson County, OK, Tillman County, OK, Archer County, TX, Baylor County, TX, Briscoe County, TX, Castro County, TX, Childress County, TX, Clay County, TX, Cottle County, TX, Crosby County, TX, Dickens County, TX, Floyd County, TX, Foard County, TX, Garza County, TX, Hale County, TX, Hall County, TX, Hardeman County, TX, Haskell County, TX, Jack County, TX, Jones County, TX, Kent County, TX, King County, TX, Knox County, TX, Lubbock County, TX, Lynn County, TX, Montague County, TX, Motley County, TX, Palo Pinto County, TX, Parker County, TX, Shackelford County, TX, Stephens County, TX, Stonewall County, TX, Swisher County, TX, Throckmorton County, TX, Wichita County, TX, Wilbarger County, TX, Wise County, TX, Young County, TX
The radar
The Dyess AFB radar (KDYX), 97 km from the middle of the area, began a volume at 21:59 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 nearest sounding before it
Fort Worth, TX (KFWD), launched 12:00Z, 10.0 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
- 3 J/kg
- Mixed-layer CIN
- -400 J/kg
- Mixed-layer LCL
- 1793 m above ground
- 0-6 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- -49 m²/s²
- 0-3 km storm-relative helicity
- 96 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
257 ACUS11 KWNS 182200 SWOMCD SPC MCD 182200 TXZ000-OKZ000-182330- MESOSCALE DISCUSSION 1787 NWS STORM PREDICTION CENTER NORMAN OK 0500 PM CDT SAT AUG 18 2012 AREAS AFFECTED...PARTS OF NWRN/WRN TX AND FAR SWRN OK CONCERNING...SEVERE THUNDERSTORM WATCH 584... VALID 182200Z - 182330Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 584 CONTINUES. SUMMARY...WHILE ISOLATED SVR STORMS REMAIN POSSIBLE ACROSS THE WW AREA...THE OVERALL THREAT IS RATHER MARGINAL. DISCUSSION...A BAND OF LOOSELY ORGANIZED CONVECTIVE CLUSTERS FROM FLOYD COUNTY TO BAYLOR COUNTY TX IS BEING UNDERCUT BY ITS ASSOCIATED COLD POOL WHILE LYING SOUTH OF ANY APPRECIABLE MID-LEVEL FLOW -- I.E. PROFILER DATA DEPICTING GENERALLY LESS THAN 20 KT OF FLOW AOB 5 KM AGL. AN ISOLATED SVR WIND GUST CANNOT BE RULED OUT WITH INCIPIENT CONVECTION OVER THE SRN FLANK OF THE SWD-EXPANDING COLD POOL AMIDST A RELATIVELY DEEP BOUNDARY LAYER CHARACTERIZED BY SFC TEMPS IN THE LOWER 90S AND DEWPOINTS IN THE UPPER 50S. HOWEVER...SUCH THREAT SHOULD BE SHORT IN DURATION...AND THE SVR THREAT SHOULD QUICKLY DIMINISH FOLLOWING THE PASSAGE OF THIS BAND. MULTICELL CLUSTERS OVER THE ERN EXTENT OF THE WW AREA MAY ALSO POSE A THREAT FOR ISOLATED MARGINALLY SVR WIND GUSTS AND SMALL HAIL...THOUGH MARGINAL DEEP SHEAR AND MORE ABUNDANT CONVECTIVE OVERTURNING SHOULD KEEP ANY SVR THREAT BRIEF/ISOLATED. ..COHEN.. 08/18/2012 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FWD...OUN...SJT...LUB...AMA...MAF... LAT...LON 32399756 33100227 34820227 34289758 32399756
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 3:52 AM CDT | Mesoscale Discussion | SPC | Alfalfa, Beaver, Ellis, Harper, Woods, Woodward | 113 min |
| Aug 18, 9:29 AM CDT | Mesoscale Discussion | SPC | Alfalfa, Blaine, Canadian, Custer, Dewey, Garfield and 5 more | 91 min |
| Aug 18, 1:10 PM CDT | Mesoscale Discussion | SPC | Cotton, Jackson, Tillman | 2 hr |
| Aug 18, 2:05 PM CDT | Severe Thunderstorm Watch | SPC | Cotton, Jefferson, Tillman | 7 hr |
| Aug 17, 7:53 PM CDT | Mesoscale Discussion | SPC | Bowie | 2 hr |
| Aug 18, 6:29 AM CDT | Mesoscale Discussion | SPC | Bowie | 2 hr |
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.