Area Forecast Discussion
Issued by NWS Columbia, SC

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FXUS62 KCAE 271734
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
134 PM EDT Wed Mar 27 2024

.SYNOPSIS...
A slow-moving cold front is expected to bring unsettled weather
through early Thursday. Rain chances diminish on Thursday as
high pressure approaches but a tight pressure gradient will
likely produce breezy conditions. High pressure and upper
ridging should keep the region dry on Friday and into the
weekend with a significant warming trend into early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Fairly sharp temperature contrast has set up across the forecast
area as a slow moving cold front pushes eastward. Eastern cwa
remains in the upper 60s to lower 70s, while the western
counties are only in the low to middle 50s. This front will
continue to slowly moves eastward. A good temperature drop will
occur in areas as the front moves through during the afternoon,
and this makes for a rather challenging afternoon temperature
forecast. More uniform this evening and tonight with expected
cloud cover and cooler air overspreading the entire forecast
area, with overnight lows in the low to middle 50s expected.

As for rainfall, the initial shortwave energy moving northward
along this front produced showers and isolated thunderstorms
this morning, but that activity is pushing out of the forecast
area. Additional energy moving through southeastern Ga should
cause some redevelopment of showers through the afternoon and
evening hours. Best instability will be across areas east of the
front, more so along the coastal plain of SC/Ga, and would
expect better thunderstorm coverage in that location. Remainder
of the cwa will see general showers this afternoon and evening,
with an isolated thunderclap still possible. In addition, with
the previous rainfall and the potential for periods of moderate
rainfall, can not rule out localized flooding. Later tonight,
showers and storms will remain possible across mostly the
eastern cwa, with heavy rainfall expected along the frontal
boundary. Rain chances will slowly diminish through the night as
the front moves further east.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Thursday and Thursday night: Precipitation is expected to be
moving out of the forecast area Thursday morning as an
approaching upper trough induces coastal low development off the
Carolina coast which will then lift northeastward to the Outer
Banks through the day. So will continue with some lower chance
pops in the morning then diminish by afternoon. As the shortwave
moves across the forecast area the deeper moisture will shift
offshore through the morning and PWATs fall below a half inch by
00z Friday with increasing 700mb northwesterly flow and 850mb
flow eventually shifting to the northwest through the day.

Skies should begin to clear from west to east in the afternoon
as the upper trough axis shifts eastward off the coast.
Temperatures on Thursday will be somewhat dependent on how fast
skies can clear out, especially lower clouds but should be aided
by afternoon sunshine and the downsloping flow which will be
offsetting some weak cold advection. Expect high temperatures to
be near to slightly below normal with highs in the 60s to
possibly around 70 degrees in the CSRA. Despite clearing skies
Thursday night as drier air moves into the region, ideal
radiational cooling conditions are not expected due to a
continued pressure gradient between the departing low off the
Mid-Atlantic coast and high pressure along the Gulf Coast
states. Expect winds to remain up a bit overnight keeping the
boundary layer mixed, but cold advection should support lows
falling into the upper 30s to lower 40s.

Friday and Friday night: Upper heights begin to rise across the
southeast in the wake of the departing upper trough off the
east coast with a dry air mass in place and PWATs around a half
inch. Generally mostly sunny skies expected although some thin
high cirrus clouds may be possible spilling down the east side
of the approaching upper ridge axis. Temperatures are expected
to rebound back to near normal with highs expected around 70 to
lower 70s. A modified air mass and still not ideal radiational
cooling Friday night should yield slightly warmer low
temperatures in the mid 40s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Relatively high confidence forecast in the extended period
through early next week with global ensembles in remarkably good
agreement with the overall 500mb pattern and surface
reflections. Generally zonal 500mb flow east of the Rockies on
Saturday with a deep upper low digging southward down the west
coast while low pressure tracks across the Great Lakes into New
England pushing a front through the Ohio Valley. This front
becomes parallel to the upper level flow on Sunday and never
really comes close to the forecast area.

As the upper low moves eastward into the four corners region
and toward the southern Plains late weekend into early next week
the downstream ridging amplifies a bit, with ensemble means
above the 90th percentile. At the surface, high pressure will be
centered over the western Atlantic with southwesterly winds
circulating warm air from the Gulf into the forecast area
beneath the upper ridging. This should result in a significant
warming trend with high temperatures pushing into the 80s Sunday
through Tuesday, nearly 10-15 degrees above normal. Overnight
lows will also trend well above normal by early next week with
lows in the 50s to around 60 degrees by Sunday night into early
next week.

The next chance of rain returns mid week as the southern stream
upper trough phases with some northern stream energy knocking
down the upper ridging with PWATs rising to 150-200 percent of
normal.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Showers and thunderstorms likely this afternoon and evening.

A front over the region will keep ceiling restrictions in place
through the day. Showers and thunderstorms will develop along
the front this afternoon leading to periods of heavy rain and
additional restrictions. Winds east of the front will be out of
the SSE while winds behind the front will be NW. This may cause
periods when terminals bounce between wind direction or become
variable through the evening.

Tonight, convection should diminish through the evening with
rain exiting the forecast area on Thursday morning. Low level
moisture overnight will keep ceilings down. IFR conditions are
most likely but LIFR will also be possible. Visibilities could
also be reduced at times overnight, particularly at AGS and OGB
or locations that receive heavy rainfall this afternoon.

Winds will pick up out of the N on Thursday morning with gusts
up to 25 kts possible. Conditions should improve through the day
Thursday with sites possibly returning to VFR by 18Z but
confidence is low.

EXTENDED AVIATION OUTLOOK...Breezy winds on Thursday and Friday
behind a front. Widespread restrictions unlikely through
Monday.

&&

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

&&

$$


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