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000
FXUS64 KOHX 180730
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
230 AM CDT Thu Apr 18 2024

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(Today through Friday)
Issued at 229 AM CDT Thu Apr 18 2024

Dry conditions prevailing as these early morning hours have
progressed and prevalence of dry atmospheric conditions will
continue through morning hours today. With favorable dewpoint
depressions, and in some locations light to calm winds with breaks
in cloud coverage, patchy fog could develop and continue until
mid morning hour today.

Let`s take a look at two events that will be potential major
players in potential of strong to severe storm development
across mid state region this afternoon through tonight. First,
possible development of showers and storms from our southwest as
afternoon hours progress today. In examining latest CAMs, North
American, and even global model trends, all generally agree that
convection will move in from southwest today, but some CAMs have
it as early as early afternoon hours across Nashville Metro area
with some only isolated convection across far southwest late.
During afternoon hours today, as region continues under warm
sector development, with it not being out of the question that
record highs could be approached or reached at least across
locations west of Cumberland Plateau Region. Thus this seasonally
warm rich atmospheric airmass looks to be supportive of robust
convective development with upper level shortwave movement
timing eastward into western half of our area key. Model sounding
derived CAPE values could be as high as around 2,000 J/KG, with
PW values around 1.5 inches, with SRH values potentially in
lower 100s, with supportive low to mid level lapse rates for
robust convection development. The coverage of afternoon
convection will play a key role in how much atmosphere has been
worked over and what impacts second wave of convection will bring.
If just isolated convection develops across western portions of
our area this afternoon, secondly, the better chance of strong to
severe thunderstorm development looks to be as evening into at
least first part of overnight hours progress as a strong surface
cold front approaches and then moves into mid state region from
our northwest with a line of showers and storms developing ahead
of it. On average of model derived soundings, not as much overall
CAPE, but a little more SRH than afternoon hours expected tonight,
and with zonal flow aloft supporting multiple shortwave
disturbances in flow aloft. Brief heavy rainfall during evening
hours looks also possible from stronger convection development.
Still looking at 8 PM to 1 AM time frame for greatest risk of
strong to severe storm potential with a general 3 PM to 3 AM time
frame for overall concern of strong to severe storm development.
Within these two waves of potential convective development, lean
toward strong to damaging winds being primary storm threat, but
certainly can not rule out development of large hail or even
development of isolated tornadoes, especially for locations
approaching Land Between the Lakes Region where better dynamics
are expected to be in place supporting this development
respectively. Surface cold front should be positioned just west of
Cumberland Plateau Region just after sunrise on Friday. Thus lows
tonight will range in lower 60s across much of area and may dip
into mid 50s across northwestern portions. Surface cold front will
continue pushing southeastward as day on Friday progressing, with
most showers and storms pushing east of mid state region by late
afternoon hours on Friday. Highs on Friday across eastern and
southern locations will remain relatively seasonally warm, but
highs will be cooler across northern locations mainly in upper
60s.

&&

.LONG TERM...
(Friday Night through next Wednesday)
Issued at 229 AM CDT Thu Apr 18 2024

Dry conditions will once again prevail Friday night with lows
close to seasonal normal values. Greatest depth of atmospheric
moisture will continue to be west and south of region but enough
moisture looks to be in place across our area interacting with
subtle upper level shortwave passages in zonal flow aloft to
support development of isolated to scattered light showers
Saturday through Sunday afternoon as cold air advection settling
in behind above mentioned short term cold frontal passage works
into region in association with strong northern plains surface
high pressure apex influences that will drop southeastward and be
positioned just west of mid state region by shortly after sunrise
on Monday morning. After seasonally cold lows Sunday night mainly
upper 30s to lower 40s, mid 30s Cumberland Plateau Region, and as
these surface high pressure influences shift eastward, dry
conditions will prevail Sunday night through Monday night as
southerly low level atmospheric flow becomes established and thus
a warm air advection pattern begins to become established. Look
for temperatures to return to around seasonal normal values by mid
week with a north to south frontal passage Tuesday night into
Wednesday bringing shower and thunderstorm chances back to our
region.

&&

.AVIATION...
(06Z TAFS)
Issued at 1214 AM CDT Thu Apr 18 2024

Low clouds and patchy fog are expected to develop tonight,
particularly along the Plateau where confidence is highest in MVFR
to IFR conditions. Low clouds could impact KBNA, KMQY, and KCKV,
too, by 12Z. Conditions should improve back to VFR between 15Z and
18Z. Showers and thunderstorms then develop Thursday afternoon and
evening. Lots on uncertainty in coverage and timing of this
activity. For now, VCTS has been included for KCKV late afternoon
with SHRA expanding eastward through 06Z.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      87  62  72  51 /  40  80  50  20
Clarksville    85  55  69  48 /  50  90  10  20
Crossville     82  61  71  48 /  10  70  70  10
Columbia       85  63  73  51 /  50 100  50  20
Cookeville     83  62  70  50 /  10  80  70  20
Jamestown      83  60  69  47 /  10  70  70  20
Lawrenceburg   85  65  73  52 /  50  90  50  10
Murfreesboro   87  64  73  51 /  40  80  60  20
Waverly        86  57  70  49 /  50 100  10  20

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...JB Wright
LONG TERM....JB Wright
AVIATION.....Clements