Area Forecast Discussion
Issued by NWS Nashville, TN
FXUS64 KOHX 240958
Area Forecast Discussion
National Weather Service Nashville TN
458 AM CDT Fri Mar 24 2017
FOR 12Z AVIATION DISCUSSION.
Current temperatures are mild, in the mid to upper 50s. Upper
ridge axis is located almost directly over our area this morning,
but it will be moving east throughout the day today. Gradient
winds will be on the increase this afternoon, however they should
stay below advisory criteria. Gusts are expected to be out of the
south around 25 to 30 knots. The closed upper low over the plains
will head east today, stirring up showers and thunderstorms for
areas west of the Mississippi River. Friday night into Saturday
morning, the low will take a turn toward the northeast and push
showers and thunderstorms into western Tennessee by early Saturday
morning. We could see a few isolated showers and thunderstorms in
our western most counties near the Tennessee River before 7am
Saturday. Precip coverage will slowly spread from west to east
across the CWA on Saturday. Surface winds will be slightly higher
during the day Saturday than today. Still looking like wind speeds
will be below advisory criteria, but it will certainly be a gusty
day. Best chance for showers and thunderstorms will be in the
afternoon and evening on Saturday. Both the GFS and NAM are
showing max CAPE values around 1000 to 1200 j/kg over southwestern
Middle Tennessee for a few hours in the late afternoon and early
evening. This coincides with about 30 to 40 knots of bulk shear.
With the shear, instability and forcing from the passing low
pressure system to the northwest we could certainly see some
strong storms across much of the area, with isolated severe
possible in the southwestern counties. SPC currently has a small
portion of Wayne and Lawrence counties in a Slight Risk, while the
remainder of Middle Tennessee is under a Marginal or General
thunderstorm outlook. Showers are expected to continue overnight
and into Sunday morning. Rainfall may be heavy at times. One half
to three quarters of an inch of rainfall is expected from Saturday
morning through Sunday morning.
We should see a break in the precip on Sunday evening, with the
exception of a few lingering showers over the southern and eastern
counties. The next mid level wave will sweep across the plains
Sunday night and bring another chance of strong storms to Middle
Tennessee Monday. Instability and shear are decent enough for the
possibility of some severe storms. The upper shortwave will follow
the same path as the previous one and head off to the northeast on
Tuesday. We may get a brief break in activity mid week with only
the chance of a few showers and isolated thunderstorms on Tuesday,
then a small chance of showers Wednesday. The wet pattern
continues as another upper low brings the threat of showers and
storms on Thursday.
Temperatures will be just above normal throughout the forecast
period. Upper 60s and mid 70s will be common most days. Overnight
lows will mainly be in the 50s.
12Z TAF DISCUSSION.
This taf cycle expected to be largely VFR but the onset of the
clouds this morning likely to bring short period of MVFR cigs
CKV/BNA. Winds will remain gusty from the south...reaching 25knt
most of the day.