ZCZC SPCSWOMCD ALL
ACUS11 KWNS 180830 
SPC MCD 180830 
OHZ000-KYZ000-TNZ000-ALZ000-MSZ000-181230-

Mesoscale Discussion 1898
NWS Storm Prediction Center Norman OK
0230 AM CST Sun Dec 18 2016

Areas affected...Northeast MS...far northwest AL...west and middle
TN...central to northeast KY...and southern OH

Concerning...Freezing rain 

Valid 180830Z - 181230Z

SUMMARY...Surface temperatures will continue to fall overnight in
the wake of the cold front.  As readings fall below 32 F, freezing
rain with rates of 0.05-0.10 inches per hour will continue to be the
initial wintry precipitation-type, as a 70-100 mile wide swath of
stratiform rain spreads across the discussion area through 11-12Z.
Sleet should mix in from west to east as the cold air deepens.

DISCUSSION...Strong low-level cold air advection will continue in
the post-frontal air mass across the discussion area from northern
MS to southern OH overnight, as the cold front advances toward the
Appalachian Mountains.  Trends in mosaic radar imagery indicated a
70-100 mile wide swath of stratiform precipitation in the wake of
the cold front.  As surface temperatures fall below 32 F in this
post-frontal air mass, a residual warm layer above the surface will
support freezing rain as the primary precipitation type as has
already been observed in northern MS through west TN, southwest KY
to central OH.  Precipitation rates of 0.05-0.10 inches per hour
will be common, though locally higher rates cannot be ruled out. 
Meanwhile, forecast soundings suggest as the vertical thermal
profile cools in the lower-troposphere, the warm nose will diminish
allowing sleet to mix in and or become the primary precipitation
type.

..Peters.. 12/18/2016

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...RLX...JKL...ILN...LMK...OHX...HUN...PAH...MEG...

LAT...LON   34468935 35438909 37238646 38218473 39258264 39018230
            38458259 37088432 36738502 35908614 35448668 34808753
            34168840 34188910 34468935 

NNNN