415 
FXUS64 KMRX 120909
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
409 AM EST Sat Jan 12 2019

.SHORT TERM...(Today through Sunday)... 
Isentropic lift is producing some light precip across the area this 
morning, but much of it is not reaching the ground as the sub-750 mb 
layer remains very dry as seen in the 00Z OHX sounding and models 
soundings in East TN. CSV has reported snow as well as a few sites 
in E KY so some spots on the Plateau and higher elevations of SW 
VA/NE TN may see light snow this morning, but with very little 
accumulation. With weak lift and dry low levels, PoPs will remain in 
the low to slight chance range through most of today, but increase 
late in the afternoon as southerly 850 mb winds bring increasing 
moisture advection and synoptic lift strengthens ahead of the 
approaching closed mid/upper level circulation. Categorical PoPs 
will be forecast tonight when forcing peaks in the 00-06Z time 
frame. After 06Z, we begin to see midlevel drying begin from the 
west, and with the lack of moisture in the dendrite growth zone, 
precip will become mainly drizzle by Sunday morning in most spots. 
Low level saturation with dry air aloft and weak low level forcing 
contines through Sunday, and will have categorical drizzle with a 
chance of rain all day. Late in the day, the freezing level starts 
to drop as the midlevel trough moves overhead, and the TN mountains 
may see some freezing drizzle, mainly above 4000 ft.

.LONG TERM...(Sunday night through Friday)...
Sunday night into Monday night low pressure will have moved off the 
coast with another upper trough moving into the Tennessee Valley.
Mostly lighter precipitation lingering with light rain mixed with
snow changing to drizzle/freezing drizzle or very light freezing 
rain as moisture decreases Monday and Monday night. Temperatures 
Sunday night will be above freezing except at the highest 
elevations of east Tennessee mountains and southwest Virginia. 
Snowfall amounts will be less than 1 inch and ice accumulation 
amounts only a couple hundredths of an inch. Monday will stay cold
as higher pressure tries to build in behind developing low off 
the mid atlantic coast. Also low clouds and lingering moisture 
will hold temperatures down. Followed closer to NAM guidance for 
highs only mid to upper 30s southwest Virginia and near 40 to 
lower 40s elsewhere. Monday night moisture finally moves out with 
lingering drizzle/freezing drizzle possible. As high pressure 
builds in Tuesday through early Thursday temperatures will warm 
into the 40s to mid 50s and there will be at least two days of 
sunshine. Another weak front will approach late Thursday into 
Friday with moisture increasing from the southwest. Right now only
low chances for rainfall but staying in a mild pattern for 
temperatures.


&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             42  40  47  38 / 100 100  40  30 
Knoxville McGhee Tyson Airport, TN  41  39  44  37 /  90 100  50  40 
Oak Ridge, TN                       41  38  44  36 / 100 100  50  40 
Tri Cities Airport, TN              41  35  43  33 /  90 100  60  40 

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...None.
TN...None.
VA...None.
&&

$$

DGS/TD