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561
FXUS62 KCAE 201907
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
307 PM EDT Fri Sep 20 2024

.SYNOPSIS...
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High pressure building over the region will result in dry and
warm conditions through Sunday. A return to more seasonable
conditions is expected early to mid week along with a slight
chance of showers.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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Key Message(s):

- Patchy fog, locally dense at times, possible late tonight.

An upper level trough axis continues to shift off the Mid-
Atlantic coast, with ridging building in from the southern
Plains. At the surface, high pressure continues to build
southward from the Mid-Atlantic.

A rather extensive cumulus field has developed across the area
this afternoon. A weak short wave is expected to move across the
area within the northwest flow aloft this afternoon, and could
trigger a few isolated showers/thunderstorms mainly across the
northern and possibly central Midlands. Temperatures are tending
warmer than normal so far this afternoon, with highs expected to
be in the mid to upper 80s most areas.

The diurnal cumulus will quickly dissipate with the loss of
daytime heating early this evening, leaving mainly clear skies
through most of the overnight hours. The combination of
light/calm winds, clear skies, and ample low level moisture will
support the formation of low stratus and patchy fog late
tonight. Many of the high resolution mesoscale models and the
NBM support the greatest probabilities of low ceilings and
reduced visibilities across the northern/central Midlands, but
cannot rule out the possibility extending southward into parts
of the CSRA. The fog could even be locally dense at at times.
Low temperatures will generally be in the mid to upper 60s.
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.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
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Key Message(s):

- High pressure over the area this weekend with above normal
temperatures.

Trough will move offshore this weekend with potent upper building
over the Carolinas this weekend. Surface high pressure centered over
New England and the Mid-Atlantic will continue to dominate our
weather, with dry conditions expected despite lingering moisture in
PWATS around 1.2"-1.5". The increasing heights is expected to lead
to above normal temperatures both during the day and night, with
highs in the upper 80s Saturday and perhaps low 90s Sunday. NBM
probabilities of max temps greater than or equal to 90 degrees on
Sunday are over 70 percent across much of the area south and west of
the I-26 corridor. Values in excess of 90 percent are present
through much of the CSRA. Normal high temperatures this time of year
are in the low to mid 80s for Columbia.
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.LONG TERM /MONDAY THROUGH THURSDAY/...
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Key Message(s):

- Generally benign weather with above normal temperatures
- Chances of rain increase midweek with limited confidence

Upper ridge remains in place early next week with a few shortwaves
riding up and over. A few may graze the northern forecast area with
a slight chance of showers on Tuesday or Wednesday, since moisture
levels are expected to remain fairly steady with GEFS mean PWATs
between 1.3" and 1.6". Warm, above normal temperatures are expected
to continue through the middle of the week, with highs in the mid
80s to low 90s.

Plenty of uncertainty remains in the forecast from Thursday onward
as ensembles and deterministic models continue to disagree on the
evolution of a potential tropical system in the Gulf of Mexico.
There is potential we could see a shift in the overall pattern
across our area late next week, but its too early for much
speculation. However, temperatures may take a minor tick downwards
but still remain above normal on Thursday.
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&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
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VFR conditions will prevail into the overnight hours, with
temporary IFR or lower conditions possible in low stratus/fog
around daybreak Saturday.

Diurnal cumulus has resulted in broken VFR level ceilings at the
terminals this afternoon. While an isolated shower/thunderstorm
is possible across parts of the central Midlands, probabilities
are too low to include mention at any of the TAF sites. The
cumulus will quickly dissipate with the loss of diurnal heating
early this evening, leaving mainly clear skies overnight.

The combination of light/calm winds, clear skies, and ample low
level moisture will support the formation of low stratus and
patchy fog late tonight. Many of the high resolution mesoscale
models and the NBM support the greatest probabilities of low
ceilings and reduced visibilities around KCAE/KCUB/KOGB, but
cannot rule out the possibility extending southward into parts
of the CSRA and impacting KAGS/KDNL as well. As a result, the
TAFs show temporary IFR or lower conditions at all terminals
from about 10-14Z.

Rapidly improving ceilings/visibilities are then expected after
14Z with a return to VFR conditions at all terminals.

EXTENDED AVIATION OUTLOOK...No significant impacts to aviation
expected through Tuesday.
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&&

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

&&

$$