Alert archive / Texas / Mesoscale Discussions in 2011
Mesoscale Discussion 2193
The Storm Prediction Center issued this mesoscale discussion at Sep 18, 2011, 10:31 PM CDT for 5 counties in Arkansas; 5 parishes in Louisiana; 23 counties in Texas. It was in force for 59 min.
The area
The outline as issued.
The facts
- Issued
- Sep 18, 2011, 10:31 PM CDT (03:31 UTC)
- Expired
- Sep 18, 2011, 11:30 PM CDT
- In force
- 59 min
- Issued by
- the Storm Prediction Center
All 33 counties
Columbia County, AR, Hempstead County, AR, Lafayette County, AR, Miller County, AR, Nevada County, AR, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Webster Parish, LA, Anderson County, TX, Bosque County, TX, Cass County, TX, Cherokee County, TX, Ellis County, TX, Freestone County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Hill County, TX, Limestone County, TX, Marion County, TX, McLennan County, TX, Nacogdoches County, TX, Navarro County, TX, Panola County, TX, Rusk County, TX, Shelby County, TX, Smith County, TX, Somervell County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX
The radar
The Shreveport radar (KSHV), 145 km from the middle of the area, began a volume at 03:33 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, 3.5 hours before the alert went out and 154 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
- 571 J/kg
- Mixed-layer CIN
- -23 J/kg
- Mixed-layer LCL
- 1671 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 32 m²/s²
- 0-3 km storm-relative helicity
- 121 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 5.5
The text
As transmitted, in the capitals the NWS used until 2016.
876
ACUS11 KWNS 190332
SWOMCD
SPC MCD 190331
ARZ000-LAZ000-TXZ000-190430-
MESOSCALE DISCUSSION 2193
NWS STORM PREDICTION CENTER NORMAN OK
1031 PM CDT SUN SEP 18 2011
AREAS AFFECTED...ARKLATEX INTO CNTRL TX
CONCERNING...TORNADO WATCH 853...854...
VALID 190331Z - 190430Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 853...854...CONTINUES.
NUMEROUS CELL MERGERS AND THUNDERSTORM CLUSTERS HAVE EVOLVED INTO A
SQUALL LINE FROM SWRN AR...SWWD INTO CNTRL TX. THIS ACTIVITY IS
PROPAGATING SEWD AT ROUGHLY 25KT WITH A FEW SURGING SEGMENTS
ADVANCING UPWARDS OF 30KT TOWARD NWRN LA. LATEST RADAR DATA
SUGGESTS HAIL IS THE MOST LIKELY SEVERE THREAT...ESPECIALLY WITH THE
CONVECTION OVER CNTRL TX...BUT LOCALLY DAMAGING WINDS ARE ALSO
POSSIBLE AS SQUALL LINE IS SURGING A BIT AND HAS AN OVERALL
EXPANDING PRECIP SHIELD. GIVEN ITS CURRENT SPEED IT SHOULD ADVANCE
TO A POSITION FROM NCNTRL LA...ARCING SWWD TO THE CWA BORDER OF
FWD/HGX BY 06Z.
..DARROW.. 09/19/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LZK...SHV...HGX...FWD...
LAT...LON 32199797 32879505 33849366 33389264 31659360 31189685
32199797SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 18, 7:58 PM CDT | Mesoscale Discussion | SPC | Bosque, Brown, Collin, Comanche, Concho, Cooke and 24 more | 62 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.