Alert archive / Tennessee / Mesoscale Discussions in 2016

Mesoscale Discussion 87

February 3, 2016Graham County, Swain County, North Carolina; 11 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Feb 3, 2016, 4:58 AM EST for Graham County, Swain County, North Carolina; 11 counties in Tennessee. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued
Feb 3, 2016, 4:58 AM EST (09:58 UTC)
Expired
Feb 3, 2016, 6:30 AM EST
In force
92 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Graham County, NC, Swain County, NC, Blount County, TN, Cocke County, TN, Grainger County, TN, Greene County, TN, Hamblen County, TN, Hancock County, TN, Hawkins County, TN, Jefferson County, TN, Knox County, TN, Monroe County, TN, Sevier County, TN

The radar

The Knoxville radar (KMRX), 34 km from the middle of the area, began a volume at 10:00 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

Nashville Metro, TN (KBNA), launched 00:00Z, 10.0 hours before the alert went out and 272 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, Nashville Metro, TN at 00:00Z on 2016-02-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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, Nashville Metro, TN at 00:00Z on 2016-02-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 479 square meters per square second.1939587897117Sfc1 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
2 J/kg
Mixed-layer CIN
-189 J/kg
Mixed-layer LCL
1227 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
479 m²/s²
0-3 km storm-relative helicity
645 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

647 
ACUS11 KWNS 030959
SWOMCD
SPC MCD 030958 
TNZ000-NCZ000-031130-

MESOSCALE DISCUSSION 0087
NWS STORM PREDICTION CENTER NORMAN OK
0358 AM CST WED FEB 03 2016

AREAS AFFECTED...ERN TN

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 030958Z - 031130Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...A MODEST THREAT FOR ISOLATED STRONG TO DAMAGING WIND GUST
WILL PERSIST OVER NERN TN NEXT COUPLE HOURS. OVERALL THREAT IS NOT
EXPECTED TO BECOME SUFFICIENT FOR A WW.

DISCUSSION...A STRONGLY FORCED LOW-TOPPED LINE OF CONVECTION NEAR
KNOXVILLE AND SWD INTO SERN TN IS MOVING EAST AT NEAR 50 KT. STRONG
CONVERGENCE ASSOCIATED WITH INTENSE 60-70 KT SLY LLJ WILL MAINTAIN
THE LINE NEXT COUPLE HOURS. CAPE IS VERY LIMITED AND SHALLOW...AND
LIGHTNING ACTIVITY IS EXPECTED TO REMAIN SPARSE/SPORADIC.
NEVERTHELESS...POTENTIAL WILL EXIST NEXT HOUR OR TWO FOR SOME OF THE
HIGH MOMENTUM AIR ALOFT TO BE TRANSPORTED TO THE SFC WITHIN BANDS OF
HIGHER REFLECTIVITY.

..DIAL/CORFIDI.. 02/03/2016

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

ATTN...WFO...GSP...MRX...

LAT...LON   36028407 36498359 36588259 36058256 35708328 35178402
            35178455 36028407

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 3, 1:56 PM ESTMesoscale DiscussionSPCAnson, Hoke, Richmond, Robeson, Scotland2 hr
Feb 2, 7:13 PM ESTMesoscale DiscussionSPCBenton, Carroll, Chester, Crockett, Decatur, Fayette and 15 more2 hr
Feb 2, 9:50 PM ESTMesoscale DiscussionSPCBedford, Cannon, Cheatham, Coffee, Davidson, DeKalb and 26 more55 min

Nearby

Mesoscale Discussions in Tennessee, 2016Mesoscale Discussions in North Carolina, 2016Every mesoscale discussion in 2016

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.