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000
FXUS64 KOHX 192308
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
608 PM CDT Sun Aug 19 2018

.UPDATE...
FOR 00Z AVIATION DISCUSSION.

&&

.DISCUSSION...

Only isolated showers were observed across Mid Tn this afternoon,
and this trend will continue into the evening. Most people will
not receive rain, and the rain will be brief for those who do.
Patchy fog will form late in the night, mainly for the Upper
Cumberland Region. By daybreak, cLouds will start to thicken, and
scattered showers and thunderstorms will begin moving into our
far western counties as the next wx system approaches.

Monday through Tuesday, a fairly strong low pressure by August
standards will move across the Mid Mississippi Valley and into
the Great Lakes Region. A trailing cold front will approach Middle
Tennessee bringing a good chance for showers and thunderstorms
Monday through Tuesday morning. We do not expect rainy wx the
entire time. In fact, much of Monday may be rain-free. But, there
will be at least a couple of waves of showers and storms crossing
the area. Overall, the greatest rain potential will come late
Monday afternoon and evening. This will also be the time of
greatest potential for some strong to marginally severe
thunderstorms. SPC has most of our area is under a marginal risk,
with our far western counties under a slight risk. Model
parameters do not look impressive, but there will be around 30KT
bulk shear with adequate CAPE to cause some thunderstorm
organization. Damaging wind gusts will be the main concern. Showers
and some storms may linger into Tuesday morning, but a pre-
frontal trough / dry slot will shut off most of the rain by
Tuesday afternoon. Rainfall totals near 1 inch are expected for
this event, but locally heavy downpours could produce 2 or 3.
Thunderstorms will move fast enough to keep flooding potential
very limited.

Cold frontal passage will occur late Tuesday or early Wednesday,
followed by some refreshingly cooler and less humid air for
Wednesday through Thursday. Wednesday and Thursday will have
highs mostly in the lower 80s. Overnight lows will fall near 60,
except mid to upper 50s for the Upper Cumberland.

Looking ahead to next weekend, upper heights build quickly, so
August heat and humidity will return. Along with that, isolated
afternoon and evening thunderstorm chances will return for next
weekend.

&&

.AVIATION...
00Z TAF DISCUSSION.

Storm system gathering strength over the eastern Plains at this
time. This feature will move eastward with the associated frontal
boundary reaching the MS river around 00Z on Tues.

For the overnight period, convection should remain minimal through
08z or 09z. At that time, pre frontal troughing will be reaching
into western sections of the mid state. Thus, could see some
shower and tstm activity into our western areas. This precip will
spread eastward through the early morning hours. A brief break
from the convection may then occur. However, as the main frontal
boundary approaches, showers and tstms may flare up again in the
afternoon.

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

DISCUSSION......07
AVIATION........21