Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 02/06/21

Area Forecast Discussion

National Weather Service Columbia SC

 803 PM EST Fri Feb 5 2021

.SYNOPSIS...
Drier air has begun moving into the region as a cold front
slides south of the area. The front will stall tonight then
return northward Saturday spreading rain across the area through
Saturday night. A series of weather systems will provide
unsettled weather and chances of showers Monday through the end
of next week.

&&

.NEAR TERM /UNTIL 7 AM SATURDAY MORNING/...
Surface analysis as of 0z places the cold front near the I95
corridor, most noticeable in the robust dew point gradient and
westerly winds behind the front. Low level dry air is quickly
funneling into the area from the west with dew points in the
Upstate in the teens. ACARS soundings out of CLT do indicate a
fairly deep layer of dry air in the low levels which should
continue to move over much of the Midlands through tonight. The
front will stall just south of the forecast area which will
limit the intrusion of dry air in the southeastern FA. A
shortwave currently moving through the deep south will approach
the southern FA early tonight leading to increase chances for
rain showers where there is lingering moisture. With the
moisture gradient so tight, have limited shower chances to far
southeastern FA with the best chance in the Coastal Plain with
chances decreasing after midnight. Mid and high level clouds
continue to pass over the area but some clearing is expected in
the Piedmont. With winds decreasing, expected fairly strong
inversion to develop where clearing is observed, leading to a
low temperature gradient tonight with min temps in the low 30s
in the NW and near 40 in the SE.

&&

.SHORT TERM /7 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
A low will form along the stationary front across the Gulf and
Florida as the upper level trough moves into the Central US
Saturday morning. By afternoon, high pressure will move
northeast and off the Mid Atlantic coast. Moisture will increase
across the region as the stationary front transitions into a
warm front and begins to move northward. Weak isentropic lift
will trigger some light showers in the early afternoon. Forcing
continues to look extremely limited, so not expecting any
thunderstorm activity. Highs will be in the low 50s. PWATs
continue to increase with upper southwest flow, increasing to
1-1.2 inches by evening. The surface low will move up along the
Gulf and across eastern Georgia and South Carolina with
increasingly widespread rain overnight. Some heavy periods
possible, with an average of .3-.5 inches falling overnight.

A few wet flakes are still not out of the question in northern
and westernmost parts of the forecast area late Saturday night.
Surface temperatures will continue to be above freezing across
the FA, so if flakes do mix in, still wouldn`t expect any sort
of accumulation. Majority of precipitation will be rain. Dry air
begins to move in at lower levels early Sunday morning. Front
completely moves through around daybreak Sunday with very weak
cold air advection. Moisture will be mostly moved out as
downslope winds completely dry out low levels. Some wispy mid
level clouds, otherwise sunny. Highs in the mid to upper 50s,
with lows around normal in the mid 30s.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
High pressure will be over the region Monday with dry conditions
in place through the day then move eastward as low pressure
develops over the western Gulf States. The low will move through
the SE US Tuesday and with increasing moisture rain will return
to the area. With cold air stretched from the Great Lakes
through New England expect a weak surface boundary to remain
over the region and act at a mechanism for showers. Wednesday
night another low pressure system will be developing along the
far western Gulf Coast with southerly flow advecting moisture
northward from the Gulf into much of the region. This will again
result in increasing chances of showers especially during the
day Thursday. Temperatures will be above normal for Tuesday with
near normal for the remainder of the long term.

Through much of the long term models have differing solutions
with significant run to run changes. This has left confidence in
any specific model solution low especially for Wednesday and
Thursday.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
High confidence in VFR conditions through 15z then deteriorating
conditions expected by 18z through the end of the forecast
period.

The cold front has pushed through most of the forecast area this
evening and radar imagery shows rain well south of the
terminals. Winds have shifted to the west behind the front and
will gradually weaken through the evening becoming light and
variable.

Skies will remain overcast through the period with cigs
gradually lowering early Saturday morning as the next upper
trough approaches and overrunning isentropic lift overspreads
the region. Rain looks to hold off until after 18z but will move
over the area from south to north between 18z-00z as cigs fall
into the MVFR range as the lower level saturate.

After 21z, cigs will lower further, possibly into IFR range but
confidence not high enough to forecast at this time, and vsbys
will begin to lower in rain. Winds will veer more to an easterly
direction through the afternoon with speeds around 5 to 7 knots.

EXTENDED AVIATION OUTLOOK...Periods of restrictions are likely
Saturday night as low pressure lifts northward. There should be
a break from the unsettled weather on Sunday and Monday before
the next system moves in for mid-week.

&&

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

&&

$$