Area Forecast Discussion
Issued by NWS Nashville, TN
FXUS64 KOHX 022318
Area Forecast Discussion
National Weather Service Nashville TN
518 PM CST Fri Dec 2 2016
FOR 00Z AVIATION DISCUSSION.
Correction in this section to the time and day of low pressure
locations in last paragraph of short term discussion (changed
Monday to Tuesday).
It was mostly sunny and seasonably cool across the Mid-State this
afternoon, as a high pressure area nosed in from the Central
Plains and Middle Mississippi Valley. Temperatures across the area
at 3 pm ranged from the lower 50s along the Cumberland Plateau, to
the middle 50s to near 60 degrees elsewhere.
Satellite pics show high and mid clouds racing to get into Middle
Tennessee from the southwest, ahead of an upper level low pressure
area over the Desert Southwest. Believe skies will become mostly
cloudy over about the southwestern one half of our area by late
tonight, which means that our overnight temperature fall will be
slowed down a bit in areas southwest of Nashville, especially
after midnight. While northeastern areas will see lows dip into
the upper 20s, middle 30s are expected over the southwest.
As closed upper low migrates across northern Mexico and southern
Texas over the weekend, Middle Tennessee will find itself in a
moist isentropic pattern, with rain developing from the southwest
Saturday and Saturday night. Clouds and rain will help to keep
temperatures in the 40s on Saturday, and only fall 7 to 10 degrees
Saturday night. A similar temperature rise occurs Sunday, with
highs only in the 40s.
Our surface winds turn temporarily to the southeast on Sunday, as
850mb jet strengthens and lifts northeastward, out of Mississippi
and Alabama, across eastern and southern Middle Tennessee. This
also helps create the highest rain totals over those same areas.
Rain amounts Saturday night and Sunday are expected to range from
between one half and three quarters of an inch over the south,
with mainly a quarter to one third of an inch over the north.
Models still shows northern Mexico upper low becoming negatively-
tilted, as it rotates into east Texas and the Lower Mississippi
Valley on Monday. There could be some elevated convection in our
southwest by late Monday. However, the best chance for
thunderstorms still looks like Monday night and Tuesday, as a
surface low accompanies this shortwave, and moves from northern
Mississippi, at 06z,Tue. to near Nashville, by 12z, Tue. and then
into eastern Kentucky by noon, Tue. As usual for the Mid- State
this time of the year, it looks like a high shear/low cape event.
However, due to the dynamic potency of this system, would not be
surprised to see isolated strong-to-severe storms Monday night and
Tuesday. So, we`ll have to keep an eye on that developing
possibility over the next several days.
Following frontal passage on Tuesday, temperatures fall during
the day, with high temperatures in the 50s likely to occur early
in the day.
Generally flat temperature regime expected Tuesday night and
Wednesday, with lows in the upper 30s to middle 40s and highs in
the upper 40s to middle 50s. Rain chances decrease, with mainly
just isolated showers east and south.
Big changes in our weather are still expected Late next week, as
deep upper trough digs across the eastern United States and pulls
a huge Arctic high pressure system southward into our area.
Temperatures fall out of the 40s and into the 30s by Thursday
afternoon, along with gusty northwest winds. A rain/snow mix is
possible over western and extreme northern areas, as well as along
the Cumberland Plateau. However, any snow that mixes in should be
mainly just pretty to look at, since precip is expected to end
over most areas before temperatures fall to the freezing mark late
Thursday and Thursday night. As usual, the moisture remains a bit
deeper for a longer period of time along the Cumberland Plateau,
and would not be shocked to see a little bit of light snow over
that area Thursday night. Right now, it doesn`t look like anything more
than just a "spit," at best.
Highs next Friday are only forecast to be in the upper 20s to
middle 30s. So, it should be some seasonably good temperatures
for Christmas shopping, if nothing else.
00Z TAF DISCUSSION.
VFR will continue through the next 24 hours with mainly northeast
winds under 10kt. Cigs will develop tonight, around 25kft,
gradually lowering to 15kft Saturday as moisture streams from a
low pressure system over the southwest states.