Alert archive / Tennessee / Mesoscale Discussions in 2012

Mesoscale Discussion 2098

November 3, 2012Lee County, Monroe County, St. Francis County, Arkansas; 5 counties in Mississippi; 17 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Nov 3, 2012, 5:16 PM CDT for Lee County, Monroe County, St. Francis County, Arkansas; 5 counties in Mississippi; 17 counties in Tennessee. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
Nov 3, 2012, 5:16 PM CDT (22:16 UTC)
Expired
Nov 3, 2012, 6:45 PM CDT
In force
89 min
Issued by
the Storm Prediction Center
Chance of a watch
5%
All 25 counties

Lee County, AR, Monroe County, AR, St. Francis County, AR, Benton County, MS, DeSoto County, MS, Marshall County, MS, Tate County, MS, Tunica County, MS, Chester County, TN, Davidson County, TN, Decatur County, TN, Fayette County, TN, Hardeman County, TN, Hardin County, TN, Henderson County, TN, Hickman County, TN, Lewis County, TN, Madison County, TN, Maury County, TN, McNairy County, TN, Perry County, TN, Rutherford County, TN, Shelby County, TN, Wayne County, TN, Williamson County, TN

The radar

The Memphis radar (KNQA), 79 km from the middle of the area, began a volume at 22:20 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

Little Rock, AR (KLZK), launched 12:00Z, 10.3 hours before the alert went out and 99 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.

Skew-T log-pSkew-T log-p diagram, Little Rock, AR at 12:00Z on 2012-11-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 165 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Little Rock, AR at 12:00Z on 2012-11-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 122 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
165 J/kg
Mixed-layer CIN
-143 J/kg
Mixed-layer LCL
1329 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
122 m²/s²
0-3 km storm-relative helicity
140 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

584 
ACUS11 KWNS 032217
SWOMCD
SPC MCD 032216
TNZ000-MSZ000-ARZ000-032345-

MESOSCALE DISCUSSION 2098
NWS STORM PREDICTION CENTER NORMAN OK
0516 PM CDT SAT NOV 03 2012

AREAS AFFECTED...ERN AR / FAR NRN MS / SWRN AND MIDDLE TN

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 032216Z - 032345Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...A RISK FOR ISOLD STRONG TO LOCALLY SEVERE WIND GUSTS MAY
CONTINUE UNTIL 00Z.  PRIMARILY SUB-SEVERE HAIL MAY ACCOMPANY THE
STRONGEST UPDRAFTS.

DISCUSSION...SURFACE MESOANALYSIS SHOWS TWO SURFACE BOUNDARIES WITH
THE SERN-MOST BOUNDARY SERVING AS A FOCUS FOR TSTM DEVELOPMENT
DURING THE PAST FEW HOURS FROM ERN AR NEWD INTO MIDDLE TN.  AN
INSTABILITY PLUME EXTENDS FROM CNTRL AR NEWD INTO MIDDLE TN AND IT
BECOMES INCREASINGLY NARROW WITH NEWD EXTENT ACROSS MIDDLE TN.  AS
SUCH...40 KTS AT 6 KM AGL PER KOHX VWP AND MODERATE LOW LEVEL WLY/S
HAVE CONTRIBUTED TO MODEST MULTICELLULAR STORM ORGANIZATION.  FLOW
NEARLY PARALLEL TO THE FRONT AND ORIENTATION OF ONGOING TSTM
ACTIVITY WILL CONTINUE TO SUPPORT UPSCALE GROWTH INTO CELLULAR LINE
SEGMENTS.  THIS MAY FAVOR THE RISK FOR A FEW CONVECTIVELY-AIDED
DOWNDRAFTS CAPABLE OF AN ISOLD DMGG WIND RISK FOR ANOTHER HOUR OR
TWO BEFORE THE LOSS OF SURFACE HEATING ACTS TO WEAKEN THE STORMS.
GIVEN THE MARGINAL CHARACTER AND SHORT DURATION OF THE EXPECTED
THREAT...A SEVERE TSTM WATCH WILL NOT BE ISSUED.

..SMITH/CARBIN.. 11/03/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...OHX...MEG...LZK...

LAT...LON   34839139 35858821 36428655 35958613 35268730 34648971
            34469141 34839139

Nearby

Mesoscale Discussions in Tennessee, 2012Mesoscale Discussions in Mississippi, 2012Mesoscale Discussions in Arkansas, 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.