Area Forecast Discussion
Issued by NWS Nashville, TN
FXUS64 KOHX 261913
Area Forecast Discussion
National Weather Service Nashville TN
213 PM CDT TUE JUL 26 2016
The main concern for this forecast period is the potential for
showers and thunderstorms with locally heavy downpours. There will
be a chance for rain every day through the next 7 days. The
greatest coverage of showers and storms is expected Thursday. This
will also be the time of greatest concern for heavy downpours, and
localized flash flooding.
On the wx maps, a stationary front was located along the Ohio
River back to the Central Plains. High pressure systems were on
each side of the boundary, one over the midwest, and the other
off the southeast coast. These systems are not moving much, and
moisture will continue to build on the south side of the stalled
front. In the upper levels, high pressure covered much of the
southern United States, but a trough over the lower ms Valley and
western Gulf was splitting the ridge. This trough axis will
strengthen and lift deep moisture from the Gulf northward over
the next couple of days.
For Mid Tn, we will have isolated to scattered showers and
thunderstorms late this afternoon and early evening, with just a
few residual showers possibly hanging on late into the night. In
addition to brief heavy downpours, 1 or 2 of the storms could be
strong with gusty winds. Temperatures will be pretty much the same
as the past couple of nights with muggy lows in the low to mid
Wednesday will bring a little more coverage of showers and storms
than we have seen today. Increasing instability and moisture from
the south will bring 40-50 percent coverage by late afternoon,
with even greater coverage possible over our southwest counties.
Once again, a couple of the storms may be strong with gusty winds.
Highs will reach the upper 80s to lower 90s.
For Wednesday night and Thursday, a trough will come down from
the northwest, joining with the lower Ms Valley trough. The influx
of Gulf moisture will cause precipitable water values to climb
well over 2 inches on Thursday, with some sources showing as much
as 2.5 inches! This will set the stage for numerous showers and
thunderstorms, some with heavy downpours. Areas that receive
multiple downpours could have localized flash flooding. The latest
WPC QPF indicates the axis of heavier rainfall over the northwest
half of our area, with 1-2 inch amounts on Thursday. Remember, this
is an average across the area. Any given thunderstorm could drop
that amount on a local area in a short period of time, so some
places are likely to have much greater rainfall totals. The
extensive cloud cover and rain will limit temperatures to the low
to mid 80s for Thursday.
Looking ahead to the weekend, the coverage of rain is expected to
gradually drop back to the 30-50 percent range, but a series of
impulses from the northwest will maintain the potential for at
least scattered thunderstorms. Temperatures will continue to be
held down by clouds on Friday, but a little more sun for Saturday
and Sunday will allow temps to creep upward into the upper 80s and
lower 90s again.
Models suggest building heights next week, resulting in lower
pops with temperatures climbing well into the 90s again.
18Z TAF DISCUSSION.
Scattered showers/thunderstorms expected again this afternoon
with VCTS at all airports from 19z-01z. VFR cigs/vis anticipated
at all airports until 09z when patchy fog brings MVFR/IFR
visibility to CKV/CSV. Light westerly winds today will become
light and variable overnight.
.PRELIMINARY POINT TEMPS/POPS...
Nashville 75 92 74 85 72 / 20 50 60 80 60
Clarksville 74 89 73 84 71 / 20 50 70 80 60
Crossville 70 86 70 81 69 / 30 40 60 70 60
Columbia 73 91 73 84 72 / 20 50 60 70 60
Lawrenceburg 73 90 73 84 72 / 20 50 60 70 60
Waverly 74 90 73 83 71 / 20 50 70 80 60