Alert archive / Arkansas / Mesoscale Discussions in 2012
Mesoscale Discussion 2055
The Storm Prediction Center issued this mesoscale discussion at Oct 13, 2012, 9:37 PM CDT for 4 states. It was in force for 113 min.
The area
The outline as issued.
The facts
- Issued
- Oct 13, 2012, 9:37 PM CDT (02:37 UTC)
- Expired
- Oct 13, 2012, 11:30 PM CDT
- In force
- 113 min
- Issued by
- the Storm Prediction Center
All 65 counties
Baxter County, AR, Benton County, AR, Boone County, AR, Carroll County, AR, Conway County, AR, Crawford County, AR, Franklin County, AR, Fulton County, AR, Garland County, AR, Howard County, AR, Izard County, AR, Johnson County, AR, Little River County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Montgomery County, AR, Newton County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pope County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Sevier County, AR, Stone County, AR, Van Buren County, AR, Washington County, AR, Yell County, AR, Barry County, MO, Christian County, MO, Dade County, MO, Dallas County, MO, Douglas County, MO, Greene County, MO, Howell County, MO, Jasper County, MO, Lawrence County, MO, McDonald County, MO, Newton County, MO, Ozark County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Webster County, MO, Wright County, MO, Adair County, OK, Bryan County, OK, Cherokee County, OK, Choctaw County, OK, Craig County, OK, Delaware County, OK, LeFlore County, OK, Mayes County, OK, McCurtain County, OK, Ottawa County, OK, Pushmataha County, OK, Sequoyah County, OK, Bowie County, TX, Delta County, TX, Fannin County, TX, Grayson County, TX, Lamar County, TX, Red River County, TX
The radar
The Western Arkansas radar (KSRX), 28 km from the middle of the area, began a volume at 02:39 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
Springfield, MO (KSGF), launched 00:00Z, 2.6 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
- 135 J/kg
- Mixed-layer CIN
- -101 J/kg
- Mixed-layer LCL
- 729 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km storm-relative helicity
- 347 m²/s²
- 0-3 km storm-relative helicity
- 420 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 6.5
The text
As transmitted, in the capitals the NWS used until 2016.
755
ACUS11 KWNS 140238
SWOMCD
SPC MCD 140237
MOZ000-ARZ000-TXZ000-OKZ000-KSZ000-140430-
MESOSCALE DISCUSSION 2055
NWS STORM PREDICTION CENTER NORMAN OK
0937 PM CDT SAT OCT 13 2012
AREAS AFFECTED...PORTIONS ERN OK...EXTREME SERN KS...SRN
MO...WRN/NRN AR...EXTREME N-CENTRAL/NE TX.
CONCERNING...TORNADO WATCH 664...
VALID 140237Z - 140430Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 664 CONTINUES.
SUMMARY...BAND OF STG-SVR TSTMS WITH EMBEDDED BOW/LEWP FORMATIONS
WILL CONTINUE TO POSE PRIMARY DAMAGING GUST THREAT...AND SECONDARY
TORNADO RISK...AS IT MOVES EWD THROUGH REMAINDER WW AREA. SVR
POTENTIAL COULD PERSIST FAR ENOUGH E OF WW...INTO FAVORABLY MOIST
AIR MASS FROM ARKLATEX TO OZARKS...TO WARRANT ANOTHER WW.
DISCUSSION...PRIMARY CONVECTIVE BAND WAS EVIDENT AT 230Z FROM SGF
AND SLG AREAS TO JUST W OF FSM...SWWD THROUGH DUA/GLE AREAS...MOVING
ENEWD AT VARIABLE SPEEDS GENERALLY WITHIN 35-45 KT RANGE. GIVEN
ALIGNMENT OF MEAN-WIND AND DEEP-SHEAR VECTORS NEARLY PARALLEL TO
THIS ACTIVITY...QUASI-LINEAR CONVECTIVE MODE SHOULD REMAIN DOMINANT.
SFC DEW POINTS AND PW EACH DECREASE WITH EWD EXTENT ACROSS AR AND
ARKLATEX REGION...AND ACCORDINGLY...FCST SOUNDINGS SUGGEST
STRENGTHENING MLCINH AND DECREASING BUOYANCY EWD TOWARD MS RIVER
ATTM. HOWEVER...BENEATH 50-60 KT SWLY LLJ...SUFFICIENT AIR MASS
RECOVERY MAY OCCUR IN NARROW PRECONVECTIVE CORRIDOR TO SUSTAIN
STG-SVR CONVECTION E OF WW. EFFECTIVE SHEAR MAGNITUDES ARE
MAXIMIZED AT ABOUT 50 KT OVER ERN OK AND WRN AR WHERE CAPE LAYER
REMAINS DEEPEST. FOR NRN END OF COMPLEX...MOVING NEWD INTO
CENTRAL/ERN MO...SVR THREAT SHOULD DIMINISH GRADUALLY WITH TIME AND
NEW EXTENT AS TSTMS OUTPACE LOW-LEVEL DESTABILIZATION AND MOVE INTO
PROGRESSIVELY LOWER-THETAE AIR MASS. STILL...ISOLATED DAMAGING
GUSTS CANNOT BE RULED OUT INTO ERN MO...ESPECIALLY ON LOCAL SW- OR
W-FACING SLOPES.
..EDWARDS.. 10/14/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LZK...SGF...SHV...TSA...FWD...OUN...
LAT...LON 33789654 34509549 35279479 35849533 36689550 37219462
37719306 37279165 36409158 34969250 33329458 33259829
33789654SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 13, 10:15 PM CDT | Severe Thunderstorm Watch | SPC | Baxter, Boone, Clark, Cleburne, Columbia, Conway and 30 more | 6 hr |
| Oct 14, 1:42 AM CDT | Mesoscale Discussion | SPC | Arkansas, Calhoun, Clark, Cleburne, Cleveland, Dallas and 17 more | 93 min |
| Oct 14, 3:19 AM CDT | Mesoscale Discussion | SPC | Arkansas, Bradley, Calhoun, Cleveland, Craighead, Cross and 15 more | 26 min |
| Oct 13, 7:04 PM CDT | Mesoscale Discussion | SPC | Andrew, Atchison, Holt, Nodaway, Worth | 56 min |
| Oct 13, 8:02 PM CDT | Mesoscale Discussion | SPC | Bandera, Bell, Blanco, Bosque, Brown, Burnet and 33 more | 88 min |
| Oct 14, 1:16 AM CDT | Mesoscale Discussion | SPC | Bell, Bosque, Burnet, Coryell, Dallas, Ellis and 16 more | 89 min |
Nearby
Mesoscale Discussions in Arkansas, 2012Mesoscale Discussions in Missouri, 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.