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000
FXUS62 KCAE 091054
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
654 AM EDT Sun May 9 2021

.SYNOPSIS...
High pressure will slide further away from the region today as
low pressure moves toward the Ohio Valley allowing strong
southerly flow and increasing moisture. A cold front will move
into the region Monday and stall just south of the area resulting
in rain chances through Thursday with below normal temperatures
more likely by midweek.

&&

.NEAR TERM /THROUGH TONIGHT/...
High pressure well off the SC Coast will slide further into the
Atlantic basin as low pressure moves from the central Plains
into the Ohio Valley tonight. This will move a weak frontal
boundary currently near the NC/SC border northward while
tightening the pressure gradient. Winds this morning will become
strong and gusty with gusts around 25 mph from late morning
through the early evening hours. With these winds have issued a
lake wind advisory from 11am through 7 pm. The winds will also
cause issue with fire danger so have issued an SPS for increased
fire danger also through 7 pm. With sunset the wind gusts will
diminish however winds will remain between 8 and 10 mph into
tonight as moisture continues increasing and clouds lower and
thicken. With the cold front moving closer to the area have kept
slight chance pops for the central and western Midlands as well
as the CSRA around daybreak. High temperatures this afternoon
will be in the low to mid 80s with lows tonight in the low to
mid 60s.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Zonal flow aloft will begin to shift to weakly southwesterly which
will increase PWATs through the course of the day, increasing
to over 1.25" by afternoon. Shortwave looks to move through a
bit earlier, before some of the deepest moisture moves into the
area so while showers will be possible, QPF will be light. Winds
remain out of the SW at the surface with the cold front
approaching the area as warm advection will lead to temperatures
in the low to mid 80s, even with additional clouds and chances
for rain. Instability will remain mostly weak over much of the
area but HiRes models indicate that any capping inversion should
sufficiently weaken by mid afternoon. As a result, include a
chance for thunderstorms but coverage will likely be isolated
with limited forcing. Best chance for storms will likely be
associated with the cold front itself which won`t move into the
area until Monday evening from the north, with the front
becoming more diffuse as it moves into the forecast area. Mild
conditions Monday night with clouds remaining in place and a bit
of boundary layer wind.

High pressure moving in behind the cold front has trended stronger
in the past few model runs so have cut back pops for Tuesday with NE
winds promoting cold and dry advection, especially for the northern
Midlands. Moisture gradient will still be at least close to the
southern forecast area so have kept chance pops in the CSRA. Highs
expected to be around 5 to 10 degrees cooler across the area as
drier air moves into the low levels but mid level moisture will
still lead to clouds across the forecast area. Modest moisture
return Tuesday night with SW flow aloft returning and shortwave
moving through the area will increase chances for showers. Tuesday
night also expected to be cooler with lows in the low to mid
50s.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
With the trend of stronger high pressure centered north of the area,
expect an additional cold front to somewhat supers moisture to
the south Wednesday. The degree of which remains in question
but GEFS ensemble probabilities have been trending drier towards
EC members so have cut back a bit on pops Wednesday, favoring
this drier trend. Temperatures will be much cooler Wednesday
with highs remaining in the 60s with additional cold advection
across the area and plenty of cloud coverage. How much moisture
gets pushed south Wednesday into Wednesday night will depend on
chances for precip Thursday as SW flow will allow deeper
moisture to return but again GEFS members favor higher QPF and
better chances in general for rain. Temperatures will continue
to be below normal through the end of the week with drier
conditions as a more amplified trough moves through with NW flow
developing behind it. Expect moderating conditions into the
weekend.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
High confidence in VFR throughout the TAF period.

Low pressure will move northwest of the area through the period
and push a weak frontal boundary near the NC/SC border northward
and away from the area. This will result in a tightening
pressure gradient and winds becoming strong and gusty. Winds
will remain light and variable through 14z then become southerly
between 8 and 10 knots and further increasing to 12 to 14 knots
with gusts up to 24 knots from 16 through 23z. Winds gusts will
diminish with sunset however winds will remain 8 to 10 knots
through the end of the period. Low clouds will begin moving into
the terminals around 10/09z however confidence in rain before
the end of the period is too low to include. Sustained winds
tonight will prevent fog development.

EXTENDED AVIATION OUTLOOK...Restrictions possible in showers
and thunderstorms through Thursday as weak low pressure and a
frontal boundary slowly cross over the region.

&&

.FIRE WEATHER...
Relative humidity this afternoon will fall to around 25 percent
and combine with surface winds around 15 mph with gusts around
25 mph to produce increased fire danger.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
GA...Lake Wind Advisory from 11 AM this morning to 7 PM EDT this
     evening for GAZ040-063>065-077.
SC...Lake Wind Advisory from 11 AM this morning to 7 PM EDT this
     evening for SCZ016-018-020>022-025>031-035-037-038-041-
     115-116-135>137.

&&

$$