Alert archive / Tennessee / Mesoscale Discussions in 2016

Mesoscale Discussion 31

January 20, 2016Craighead County, Mississippi County, Arkansas; 19 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Jan 20, 2016, 1:15 AM CST for Craighead County, Mississippi County, Arkansas; 19 counties in Tennessee. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jan 20, 2016, 1:15 AM CST (07:15 UTC)
Expired: Jan 20, 2016, 6:15 AM CST
In force: 5 hr
Issued by: the Storm Prediction Center

All 21 counties

Craighead County, AR, Mississippi County, AR, Benton County, TN, Carroll County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dickson County, TN, Dyer County, TN, Gibson County, TN, Haywood County, TN, Henderson County, TN, Hickman County, TN, Humphreys County, TN, Lauderdale County, TN, Lewis County, TN, Madison County, TN, Maury County, TN, Perry County, TN, Tipton County, TN, Williamson County, TN

The radar

The Memphis radar (KNQA), 117 km from the middle of the area, began a volume at 07:17 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 (KBYH), launched 00:00Z, 7.3 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1321 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 483 m²/s²
0-3 km storm-relative helicity: 676 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

163 
ACUS11 KWNS 200716
SWOMCD
SPC MCD 200715 
TNZ000-MOZ000-ARZ000-201215-

MESOSCALE DISCUSSION 0031
NWS STORM PREDICTION CENTER NORMAN OK
0115 AM CST WED JAN 20 2016

AREAS AFFECTED...FAR NORTHEAST AR INTO PARTS OF WESTERN AND CENTRAL
TN

CONCERNING...FREEZING RAIN 

VALID 200715Z - 201215Z

SUMMARY...LIGHT FREEZING RAIN WILL CONTINUE TO DEVELOP EASTWARD FROM
FAR NORTHEAST AR INTO PARTS OF WESTERN AND CENTRAL TN. FREEZING RAIN
RATES GENERALLY WILL BE AROUND 0.01 INCHES PER HOUR...BUT A FEW
LOCALLY HEAVIER SHOWERS WILL BE POSSIBLE. FREEZING RAIN MAY BRIEFLY
CHANGE TO SNOW BEFORE TURNING TO RAIN AFTER SUNRISE.

DISCUSSION...SURFACE TEMPERATURES CURRENTLY RANGE FROM AROUND AROUND
28 TO 31 DEGREES F ACROSS THE MCD AREA. THESE TEMPERATURES LIKELY
WILL REMAIN FAIRLY STEADY THROUGH THE NIGHT IN WEAK LOW LEVEL WARM
ADVECTION. HOWEVER...TEMPERATURES ALOFT WILL WARM SLIGHTLY AS A 50
KT SOUTHWESTERLY LLJ NOSES INTO THE REGION AHEAD OF THE APPROACHING
MID/UPPER LEVEL SHORTWAVE TROUGH. THIS WARM ADVECTION AT 850 MB HAS
LED TO A FAVORABLE THERMODYNAMIC PROFILE FOR FREEZING RAIN SHIFTING
EASTWARD FROM NORTHEAST AR INTO WESTERN AND CENTRAL TN THROUGH 12Z.
FREEZING RAIN MAY BRIEFLY CHANGE TO SNOW AS COOLER MIDLEVEL AIR
PUSHES SOUTHWARD AFTER 12-15Z...BUT IS EXPECTED TO THEN TRANSITION
TO RAIN DURING THE MORNING HOURS AS SURFACE TEMPERATURES WARM ABOVE
FREEZING. THROUGH 12Z...FREEZING RAIN RATES ARE EXPECTED TO
GENERALLY BE LIGHT...AROUND 0.01 IN/HR...BUT LOCALLY HIGHER RATES
WILL BE POSSIBLE FOR BRIEF PERIODS.

..LEITMAN.. 01/20/2016

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

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

LAT...LON   36019045 36178906 36248814 36268739 36198692 36078676
            35818675 35528692 35348714 35278748 35258855 35288957
            35309005 35509053 35709076 35839072 36019045

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 19, 9:36 PM CST	Mesoscale Discussion	SPC	Baxter, Boone, Carroll, Clay, Cleburne, Conway and 29 more	5 hr

Nearby

Mesoscale Discussions in Tennessee, 2016 Mesoscale Discussions in Arkansas, 2016 Every 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.