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854
FXUS62 KCAE 180107
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
907 PM EDT Fri May 17 2024

.SYNOPSIS...
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Chances of showers and thunderstorms will continue overnight as a
weak system begins to slowly cross the region. Rich moisture across
the region will keep rain chances likely lingering into Sunday.
Cooler and drier air moves in for Monday and Tuesday with
temperatures rebounding during the middle of next week as another
ridge moves in from the west.
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&&

.NEAR TERM /UNTIL 7 AM SATURDAY MORNING/...
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Positively tilted upper trough continues to slowly progress through
over the central/southern Plains toward the Mississippi River Valley
this evening. Southwest flow aloft continues to usher in moisture
with PWATs between 1.5" and 1.7" and dewpoints in the mid to upper
60s. PW values are expected to increase overnight to between 1.7"
and 1.9", with a few locations closer to 2" across the CSRA/southern
or eastern Midlands.

Ongoing convection to our south is progged to remain out of the area
tonight. However, weak short wave energy moving through the mid
level flow is expected to generate scattered showers across the area
amid increasing isentropic lift. The latest HRRR shows a reasonable
solution, with perhaps a bit of a stronger area of showers and
thunderstorms pushing through the CSRA around daybreak. Severe
threat remains low though brief heavy rainfall is possible.

Overcast skies and a well-mixed boundary layer keep overnight lows
quite mild, only falling into the mid to upper 60s/near 70. Low
dewpoint depressions may generate some reduced visibilities in and
near shower activity.
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&&

.SHORT TERM /7 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
Positively tilted trough will continue to slowly push eastward
towards us and should be centered across the lower MS Valley by
tomorrow morning. Strong flow at 500 hPa is expected to create
strong shear profiles, and CAMs are generally showing some sort
of MCS structure to our southwest, but how far north this gets
and how fast it will be is in question. Generally, guidance has
struggled with speed and placement of convective structures like
this in recent weeks. So there is uncertainty about this, but
confidence is high that an MCS of some sort will be in central
GA at the start of this period. Ahead of this, rich moisture
should favor some instability, and given the shear in the
atmosphere, strong to marginally severe storms are again
possible depending on the location of this convection. Thinking
the best chance for this is in the southern FA, but timing and
severity is hard to piece together right now. Think it`ll be
approaching or through our FA by late morning, and if this
happens, it opens the door for some afternoon sunshine and
another round of thunderstorms in the central and northern FA.
While the strongest shear will be to our east, robust
instability is possible where we see sunshine tomorrow afternoon
so we`ll need to watch for strong strong storms along an
amorphous surface front across the northern part of SC. Highs
should generally be in the mid 80s but upper 80s are possible
for those that see more sunshine. Showers will probably hang
around into Saturday night as the trough approaches with lows in
the mid 60s expected. On Sunday, more showers and embedded
thunderstorms are possible as the trough approaches and pushes
over the region. Some uncertainty is present with where the
surface low and resultant convergence develops, adding some
overall uncertainty to rain coverage Sunday afternoon. But
confidence is high that we`ll see scattered to numerous showers
across much of the area, with highs in the upper 70s and low
80s. Showers should clear out on Sunday night as a back door
front pushes through and pushes low PW air into the area.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Confidence continues to remain fairly high in the long term
period. Cool and dry air is expected to remain in place on
Monday, with highs well below normal near 80s. Modification
quickly begins on Tuesday as high pressure shifts to our east
and ridging aloft begins to build. This should carry highs back
into the upper 80s and low 90s by Thursday. Another cold front
is forecast to approach by the Thur/Fri timeframe, with the
possibility of showers and thunderstorms in the afternoon in
association with that.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... 
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Restrictions to
begin overnight and continue into Saturday.

A few showers earlier this evening have moved out of the region,
leaving behind VFR ceilings for the time being. After sunset,
ceilings are expected to lower to eventual IFR levels after
about 07z. Guidance is not as consistent at AGS/DNL for IFR, so
addressed that with a TEMPO group. Low level moisture will also
likely lead to areas of fog overnight with scattered showers
possible. Latest guidance has been indicating less shower
coverage overnight than earlier runs, but with the low level
moisture in place, showers can`t be ruled out. Ceilings begin to
improve after 15z or 16z, and anticipated to return to VFR after
around 21z.Another round of showers and potential thunderstorms
arrives late in the period.

EXTENDED AVIATION OUTLOOK...Increased confidence in
restrictions with showers and thunderstorms continues through
Sunday night.
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&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...None.
GA...None.

&&

$$