Area Forecast Discussion
Issued by NWS Columbia, SC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KCAE 272322
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
722 PM EDT Thu Jul 27 2017

.SYNOPSIS...
A pre-frontal trough will shift over the area Friday, followed
by a strong cold front from the northwest Friday night and
Saturday. Cooler and drier conditions are then expected into
early next week as high pressure builds over the region.

&&

.NEAR TERM /THROUGH TONIGHT/...
A few showers and storms continue across the Upstate this
evening, with slow movement to the east. Hi-res models still
indicate this activity should weaken and dissipate, but can not
rule out an isolated shower or storm over the western cwa the
next few hours. Later on tonight, a short wave trough will
approach from the northwest as the nose of the upper ridge
retreats. Ahead of this trough, isolated showers may redevelop
late tonight toward the Charlotte Metro as a weak pre-frontal
surface trough nears. Clouds will generally be on the increase
from the northwest, but parts of the eastern Midlands/lower CSRA
could remain mainly clear through the night. Given that the
highest pwat values are in this area and winds will be light,
many of the hi-res models are suggesting that patchy fog could
develop and will continue to mention in the gridded forecast.
Temperatures will remain mild through the night, with lows
generally in the lower to mid 70s.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
The weak upper trough over southeast GA this evening will move
out to sea overnight. The next short wave trough and associated
weak pre- frontal surface trough will shift into the area on
Friday. Convection is expected to develop during the day,
especially during the afternoon/evening in a moderately unstable
atmosphere, aided by low-level convergence along the surface
trough and forcing for ascent from the approaching short wave
energy aloft. Expect coverage to range from numerous across the
northern Midlands, to scattered elsewhere. Conditions appear
favorable for a few of the thunderstorms to become severe,
mainly capable of producing damaging wind gusts. SPC has changed
the area from a Slight Risk for Severe Weather on Friday to an
area of Marginal Risk. The Slight Risk area has been shifted
slightly farther north into se VA and ern NC. Could see some
locally heavy rainfall with pw values around 2.0 inches.

The potential for numerous showers and thunderstorms will
continue into Friday night into Saturday as a strong cold front
crosses the area from the northwest. Models are in better
agreement as to timing...with the cold front moving east of the
Midlands by Saturday evening.

Abundant moisture and sufficient instability will support a
good coverage of showers and thunderstorms over most of the area
during the morning on Saturday, with coverage diminishing from
the northwest during the afternoon. A few severe thunderstorms
are possible into Saturday, especially across the eastern
Midlands and I-95 corridor to the coast as the front makes its
way across the area. Temperatures will be seasonable for this
time of year with highs in the lower 90s and overnight lows in
the lower/middle 70s.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
An upper level low over the Mid Atlantic will carve out a deep
upper trough over the region through Wednesday. Much cooler and
drier conditions will prevail Sunday through Tuesday as surface
high pressure builds into the region from the north and a cold
front remains well to our south. The GFS suggest the chance for
showers and thunderstorms returning by the middle of next week
as the frontal boundary to our south lifts north. Temperatures
should be much more pleasant with afternoon highs in the middle
to upper 80s and overnight lows in the mid/upper 60s. Some area
across the northern and western Midlands could see dewpoint
values in the upper 50s, much drier than the area has seen in
awhile.

&&

.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
Dry conditions over the Midlands and CSRA early this evening. An
line of convection over eastern GA is expected to weaken as it
moves eastward. Lower ceilings could develop and result in MVFR
or lower ceilings at KAGS, KDNL and KOGB toward daybreak. Fog
potential appears to be limited to KOGB based on high resolution
mesoscale models, as this area will likely have mainly clear
skies through much of the night, light winds and higher
moisture. VFR conditions should return by 14Z. Convection may
begin to develop across the area by late afternoon so used VCTS
for all TAF sites by 20Z due to uncertainties with timing and
areal coverage.

EXTENDED AVIATION OUTLOOK...Scattered mainly afternoon/evening
thunderstorms, along with late night/early morning fog/stratus
late Friday into Saturday. Drier conditions expected Sunday
into early next week.

&&

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

&&

$$


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.