Alert archive / Texas / Mesoscale Discussions in 2011
Mesoscale Discussion 2271
The Storm Prediction Center issued this mesoscale discussion at Oct 23, 2011, 1:29 AM CDT for Lafayette County, Miller County, Arkansas; Bossier Parish, Caddo Parish, Louisiana; 36 counties in Texas. It was in force for 61 min.
The area
The outline as issued.
The facts
- Issued
- Oct 23, 2011, 1:29 AM CDT (06:29 UTC)
- Expired
- Oct 23, 2011, 2:30 AM CDT
- In force
- 61 min
- Issued by
- the Storm Prediction Center
All 40 counties
Lafayette County, AR, Miller County, AR, Bossier Parish, LA, Caddo Parish, LA, Anderson County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Collin County, TX, Dallas County, TX, Denton County, TX, Ellis County, TX, Franklin County, TX, Freestone County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Hopkins County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Marion County, TX, Morris County, TX, Navarro County, TX, Panola County, TX, Parker County, TX, Rains County, TX, Rockwall County, TX, Rusk County, TX, Smith County, TX, Somervell County, TX, Tarrant County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wise County, TX, Wood County, TX
The radar
The Shreveport radar (KSHV), 158 km from the middle of the area, began a volume at 06:32 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 nearest sounding before it
Shreveport, LA (KSHV), launched 00:00Z, 6.5 hours before the alert went out and 165 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
- 79 J/kg
- Mixed-layer CIN
- -82 J/kg
- Mixed-layer LCL
- 2162 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- -5 m²/s²
- 0-3 km storm-relative helicity
- 46 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
811
ACUS11 KWNS 230629
SWOMCD
SPC MCD 230629
ARZ000-LAZ000-TXZ000-230730-
MESOSCALE DISCUSSION 2271
NWS STORM PREDICTION CENTER NORMAN OK
0129 AM CDT SUN OCT 23 2011
AREAS AFFECTED...N-CNTRL/NERN TX...ARKLATEX
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 230629Z - 230730Z
WW 869 REMAINS IN EFFECT UNTIL 08Z FOR PARTS OF N-CNTRL TX.
LOW-LEVEL REFLECTIVITY GRADIENT HAS RECENTLY TIGHTENED WITH QLCS E
OF THE CURRENT WW IN NERN TX. BUT HIGHER-LEVEL REFLECTIVITY
CONTINUES TO GRADUALLY WEAKEN AND SHOULD CONTINUE TO DO SO GIVEN
RELATIVELY WEAKER SHEAR/INSTABILITY COMPARED TO AREAS WITHIN/NEAR WW
869. ALTHOUGH ISOLATED DAMAGING WINDS MAY PERSIST FOR THE NEXT
COUPLE OF HOURS...A MORE SUBSTANTIAL INCREASE IN THE SEVERE THREAT
TO THE E OF TX APPEARS UNLIKELY ATTM.
FARTHER W...MORE INTENSE LOW/MID-LEVEL REFLECTIVITY CORES HAVE
PERSISTED IN THE NRN PORTION OF THE DFW METRO AREA WHERE A STRONGLY
VEERING WIND PROFILE EXISTS /AS SAMPLED BY THE DFW VWP/. THIS
SUGGESTS ACTIVITY SHOULD REMAIN STRONG TO SEVERE WITH ATTENDANT
RISKS OF WIND/HAIL FOR THE NEXT FEW HOURS. WITH TIME...MID-LEVEL
TEMPERATURES ARE FORECAST TO WARM AS SHORT WAVE TROUGH SHIFTS SEWD
OVERNIGHT...RESULTING IN A NET DECREASE IN INSTABILITY WITH A
PROBABLE DIMINISHING OF THE SEVERE THREAT BEYOND 08-09Z.
..GRAMS.. 10/23/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...SHV...FWD...
LAT...LON 33339782 33339681 33259520 33549428 33709380 33639336
32949329 32159363 31829412 31709469 31609602 32079773
32529812 33339782SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 22, 7:01 PM CDT | Mesoscale Discussion | SPC | Bowie, Camp, Clay, Collin, Cooke, Delta and 14 more | 119 min |
| Oct 22, 11:13 PM CDT | Mesoscale Discussion | SPC | Camp, Clay, Collin, Cooke, Dallas, Delta and 26 more | 92 min |
Nearby
Mesoscale Discussions in Texas, 2011Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Louisiana, 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.