Alert archive / Texas / Mesoscale Discussions in 2011
Mesoscale Discussion 541
The Storm Prediction Center issued this mesoscale discussion at Apr 23, 2011, 7:04 PM CDT for 15 counties in Oklahoma; 37 counties in Texas. It was in force for 86 min.
The area
The outline as issued.
The facts
- Issued
- Apr 23, 2011, 7:04 PM CDT (00:04 UTC)
- Expired
- Apr 23, 2011, 8:30 PM CDT
- In force
- 86 min
- Issued by
- the Storm Prediction Center
All 52 counties
Atoka County, OK, Bryan County, OK, Carter County, OK, Choctaw County, OK, Coal County, OK, Jefferson County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, Love County, OK, Marshall County, OK, McCurtain County, OK, Murray County, OK, Pittsburg County, OK, Pushmataha County, OK, Archer County, TX, Baylor County, TX, Brown County, TX, Callahan County, TX, Clay County, TX, Coleman County, TX, Collin County, TX, Comanche County, TX, Cooke County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Eastland County, TX, Erath County, TX, Fannin County, TX, Franklin County, TX, Grayson County, TX, Hood County, TX, Hopkins County, TX, Hunt County, TX, Jack County, TX, Johnson County, TX, Lamar County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Rains County, TX, Red River County, TX, Rockwall County, TX, Shackelford County, TX, Somervell County, TX, Stephens County, TX, Tarrant County, TX, Throckmorton County, TX, Titus County, TX, Wise County, TX, Young County, TX
The radar
The Dallas/Ft Worth radar (KFWS), 119 km from the middle of the area, began a volume at 00:07 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
Fort Worth, TX (KFWD), launched 00:00Z, 0.1 hours before the alert went out and 97 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
- 2261 J/kg
- Mixed-layer CIN
- -50 J/kg
- Mixed-layer LCL
- 1738 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 138 m²/s²
- 0-3 km storm-relative helicity
- 130 m²/s²
- Significant tornado parameter
- 0.4
- Supercell composite
- 7.5
The text
As transmitted, in the capitals the NWS used until 2016.
576 ACUS11 KWNS 240005 SWOMCD SPC MCD 240004 TXZ000-OKZ000-240130- MESOSCALE DISCUSSION 0541 NWS STORM PREDICTION CENTER NORMAN OK 0704 PM CDT SAT APR 23 2011 AREAS AFFECTED...NRN TX/SRN OK CONCERNING...SEVERE THUNDERSTORM WATCH 187... VALID 240004Z - 240130Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 187 CONTINUES. NUMEROUS THUNDERSTORMS...SOME SUPERCELLS...REMAIN OVER NRN TX. RADAR TRENDS SHOW THAT OVERALL...ROTATION HAS NOT BEEN VERY STRONG OR PERSISTENT...PROBABLY OWING TO HODOGRAPH DEFICIENCIES INCLUDING SOME WEAKNESS NOTED IN THE 2-3 KM LAYER. THIS IS QUITE APPARENT FROM THE 00Z FWD SOUNDING...AND ALSO NOTED IN RUC GUIDANCE. IN ADDITION...STORMS HAVE BEGUN TO INTERFERE WITH EACH OTHER WITH A FEW LEFT SPLITS AFFECTING THE RIGHT MOVERS. AS SUCH...THE TORNADO THREAT SHOULD REMAIN RELATIVELY ISOLATED AND BRIEF IN NATURE...BUT NONZERO. LARGE HAIL WILL CONTINUE TO BE THE PRIMARY SEVERE THREAT. THE FWD SOUNDING SHOWED A 700-500 MB LAPSE RATE OF 8.8 C/KM WITH A MEAN BOUNDARY LAYER MIXING RATIO AROUND 12 G/KG. ..JEWELL.. 04/24/2011 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...SHV...TSA...FWD...OUN...SJT... LAT...LON 33209464 31589937 33759938 35399463 33209464
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 23, 9:08 PM CDT | Mesoscale Discussion | SPC | Adair, Canadian, Cherokee, Cleveland, Craig, Creek and 26 more | 97 min |
| Apr 23, 9:53 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Atoka, Bryan, Caddo, Canadian, Carter and 47 more | 7 hr |
| Apr 23, 10:40 PM CDT | Mesoscale Discussion | SPC | Adair | 95 min |
| Apr 24, 2:02 AM CDT | Mesoscale Discussion | SPC | Atoka, Bryan, Caddo, Canadian, Carter, Cherokee and 42 more | 88 min |
| Apr 24, 4:17 AM CDT | Mesoscale Discussion | SPC | Blaine, Caddo, Canadian, Cherokee, Cleveland, Coal and 29 more | 28 min |
| Apr 24, 1:13 PM CDT | Mesoscale Discussion | SPC | Atoka, Bryan, Carter, Choctaw, Coal, Cotton and 13 more | 92 min |
| Apr 24, 2:28 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Atoka, Bryan, Carter, Cherokee, Choctaw and 31 more | 7 hr |
| Apr 24, 5:34 PM CDT | Mesoscale Discussion | SPC | Adair, Atoka, Bryan, Choctaw, Coal, Haskell and 11 more | 26 min |
| Apr 24, 5:36 PM CDT | Tornado Watch | SPC | Atoka, Bryan, Choctaw, Coal, Haskell, Johnston and 7 more | 7 hr |
| Apr 24, 6:23 PM CDT | Mesoscale Discussion | SPC | Atoka, Bryan, Choctaw, Latimer, LeFlore, McCurtain and 2 more | 2 hr |
| Apr 24, 2:19 PM CDT | Severe Thunderstorm Watch | SPC | Brown, Callahan, Coke, Coleman, Comanche, Concho and 17 more | 3 hr |
| Apr 24, 4:51 PM CDT | Mesoscale Discussion | SPC | Brown, Callahan, Coke, Coleman, Comanche, Concho and 19 more | 24 min |
| Apr 24, 4:54 PM CDT | Tornado Watch | SPC | Brown, Callahan, Coke, Coleman, Collin, Comanche and 33 more | 7 hr |
| Apr 24, 5:22 PM CDT | Mesoscale Discussion | SPC | Crockett, Edwards, Irion, Kinney, Maverick, Menard and 4 more | 83 min |
Nearby
Mesoscale Discussions in Texas, 2011Mesoscale Discussions in Oklahoma, 2011Every mesoscale discussion in 2011
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.