-- Discussion containing changed information from previous version are highlighted. --
296
FXUS62 KCAE 031040
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
640 AM EDT Fri May 3 2024

.SYNOPSIS...
Patchy fog and stratus possible early this morning. Increasing
moisture and shortwave energy will lead to active weather for
the weekend and early next week with showers and thunderstorms
likely. For the remainder of next week, expect well above normal
temperatures and at least a slight chance of showers and
thunderstorms each day.

&&

.NEAR TERM /THROUGH TONIGHT/...
Fog has become dense in the southeast Midlands, so advisory
issued until 1000 am for that area....Pressure ridge centered
off the coast of North Carolina is extending into the area this
morning and will remain in place. This will result in weak
south- easterly low level onshore flow. Expecting some stratus
and fog toward morning focused in the southeast Midlands.
Guidance is favoring stratus but will monitor for areas of dense
fog which could develop closer to dawn.

The upper ridge along the coast will shift a bit further east
today as weak short wave troughs over the Deep South move over
the area later this afternoon. Moisture will increase with south
low level flow with precipitable water increase to around 1.5
inches, possibly a little higher by early evening. A more well
defined upper trough will approach late tonight. These short
waves may trigger scattered convection by this afternoon with a
focus in the CSRA and SC Piedmont. The showers may progress into
the central Midlands by the early evening. Overall instability
appears weak with CAPE generally less than 500 J/kg. Some weak
low level convergence noted by late afternoon from the CSRA into
the west Midlands. The latest CAMS show scattered coverage
moving into the CSRA this afternoon and then moving into the
central Midlands early this evening. Lower pops east of CAE
through the day into the evening, but a few possible overnight.
Overall qpf light up to 0.10 in a few storms and focused in the
west. High temperatures today should be a little cooler than
yesterday with more cloud cover and potential for showers.
Stayed near the NBM temperature guidance, so highs in the mid
80s. Lows in the mid 60s.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
The axis of an upper level ridge shifts east of the forecast
area early Saturday morning. Southerly flow strengthens, leading
to increasing atmospheric moisture with PWAT values around 1.75
inches, well above normal for this time of year. PWAT values
remain high through Saturday night with NAEFS percentile values
99 to 99.5 percent of climatological maxima. A series of
shortwaves will move over the ridge on Saturday, first in the
morning hours then a more pronounced shortwave later in the
afternoon. The warm, moist low- level flow will lead to moderate
instability on Saturday afternoon. Mean mixed layer CAPE values
from the SPC SREF are around 1000 J/kg.

With a lack of a surface feature, we should see convective
activity coinciding with the shortwaves, with first some
scattered showers in the morning, then numerous showers and
thunderstorms in the afternoon given the abnormally moist
atmosphere. Weak 0-6km shear of 5 to 10 kts favors a pulse type
storm mode and limits the threat of organized thunderstorms. A
near saturated vertical profile also limits the threat of
downburst winds so severe weather is unlikely. Convection will
diminish through the night and into early Sunday morning as the
second shortwave moves east. With extensive cloud cover and more
widespread showers, highs on Saturday are expected to be closer
to average or a little below average.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
A persistent pattern of broad ridging over the Southeast is
expected to continue through much of the long term. The WPC
Cluster Prototype Page shows very little variance between
ensemble members until late next week. A series of shortwave
troughs are expected to move through the region bringing
unsettled weather for Sunday into early next week with at least
a high chance of showers and thunderstorms each day. Atmospheric
moisture is likely to remain well above normal through Monday
night with NAEFS PWATs at the 90th percentile of climatological
maxima. Ensemble members diverge in atmospheric moisture for the
remainder of the long term with some showing drier air pushing
into the region for Tuesday. Temperatures will be well above
normal next week, particularly the middle of next week with
highs in the low to mid 90s possible.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
VFR conditions at the moment. Restrictions in stratus, possible
fog toward morning with highest probability at OGB.


High pressure along the coast. Shallow low-level moisture across
the area this morning. Stratus/with some fog has developed
across the area. Fog is dense at OGB, IFR,MVFR fog at other
sites. But LIFR stratus is widespread or near terminals. The
stratus should lift by 14z with scattered cumulus developing by
late morning or early afternoon as low-level moisture continues
to increase. Ceilings expected to be mid level this afternoon.
Winds will be light southeast to south 5 to 10 knots. Air mass
becomes more moist in the afternoon and weakly unstable.
Convective models suggest some scattered showers or a
thunderstorms may develop in Georgia and move into the CSRA near
the AGS/DNL terminals in the afternoon. Coverage should be
scattered. The showers may move into central SC but more likely
after 00z Saturday. Low clouds may develop late tonight
resulting in restrictions.

EXTENDED AVIATION OUTLOOK...
Late night/early morning fog possible through the period.
Increased potential for showers and thunderstorms over the
Weekend into early next week.
-- End Changed Discussion --

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...Dense Fog Advisory until 10 AM EDT this morning for SCZ037-041-
     135>137.
GA...None.

&&

$$