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000
FXUS64 KOHX 270921
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
421 AM CDT Tue Jul 27 2021

.DISCUSSION...

Patchy fog north to areas of dense fog south have developed across
mid state region shortly after 27/0900Z (4 AM CDT). With areas of
dense fog formation across southern portions of mid state region,
issued a dense fog advisory earlier this morning for these
locations through 27/13Z (8 AM CDT) today.

Not expecting any organized strong to severe thunderstorm
activity through next Monday afternoon. Isolated to scattered
showers and thunderstorms expected from mid morning through
mid afternoon hours today as surface boundary meanders across mid
state region before washing out as late afternoon hours
progress. Highs today close to a carbon copy of those experienced
yesterday ranging from mid to upper 80s Cumberland Plateau Region
to lower 90s Nashville Metro Area. Afternoon heat index values
west of Cumberland Plateau Region in many locations today will
range from upper 90s to lower 100s, but continue below heat
advisory thresholds. Heat advisory thresholds for mid state
region are based on heat index values being experienced for
several locations greater than or equal to 105 degrees.

Building upper level ridging influences still expected to become
strong enough to suppress any convection potential tonight
through day on Thursday. Mild overnight lows will certainly
continue through Thursday night also. Highs on both Wednesday and
Thursday afternoons are expected to reach into mid to upper 90s,
around 90 Cumberland Plateau Region. Main locations for heat index
values around century mark on Wednesday afternoon will be those
approaching TN River Valley Region. Most locations west of
Cumberland Plateau Region will experience heat index values
around the century mark on Thursday afternoon. However, as of
this time, heat index values look like they will continue to
remain just below the 105 degree threshold.

Still looks like upper level northwesterly flow pattern will
become increasingly supportive of a potential series of shortwave
passages aloft as early as Thursday night across Upper Cumberland
Region and across entire mid state region Friday through first
part of next work week. Another summertime surface stationary
frontal boundary bringing with it little in way of any atmospheric
change is also expected to push southward through mid state
region as day progresses on Friday. Isolated to scattered showers
and thunderstorms are also anticipated Friday through at least
next Monday. Mild overnight lows and seasonably warm highs with
summer humidity values high enough to support continuance of
afternoon heat index values around 100 degrees for multiple
locations west of Cumberland Plateau Region are expected to
continue Friday into Saturday. As later half of Sunday afternoon
through nighttime hours progress, yet another summertime surface
frontal passage to our north will push through mid state region.
However, this time there will be an airmass change per strong
1020 mb surface high pressure system centered in southwest Ontario
Providence of Canada shortly after sunrise on Monday morning
pushes southeastward into Northern MI/Lower Peninsula region by
shortly after sunrise Tuesday morning. A "cooling trend" will
commence on Sunday as high temperature are only expected to be
around seasonal normal values with high temperatures lowering
to actually a few degrees below seasonal normal values by mid
portion of next work week. Lows will span the 60s both Sunday
and Monday nights.

So simply, my fellow Middle Tennesseans, uncomfortable heat and
humidity values look to continue over next several days into at
least first part of weekend, but there is relief in sight!

&&

.AVIATION...
06Z TAF DISCUSSION.

Areas of fog are expected to develop over the next few hours,
mainly MVFR, but some brief LIFR possible for CSV. Vsby reductions
from fog will be gone by 14Z. A stray TSRA could form on Tuesday,
but probability too low to include in any taf site at this time.
Winds will be generally light from the NNE through the next 24
hours.


&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      93  72  96  73  98 /  30   0   0   0   0
Clarksville    92  69  94  71  95 /  10   0   0   0   0
Crossville     85  67  89  68  89 /  30  10   0   0   0
Columbia       92  71  95  71  96 /  30   0   0   0   0
Lawrenceburg   90  71  94  71  95 /  30  10   0   0   0
Waverly        91  71  94  71  95 /  20   0   0   0   0

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 8 AM CDT this morning for Bedford-
Cannon-Coffee-Giles-Grundy-Hickman-Lawrence-Lewis-Marshall-Maury-
Perry-Van Buren-Warren-Wayne.

&&

$$

DISCUSSION......JB Wright
AVIATION........13