Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 02/25/21

Area Forecast Discussion

National Weather Service Columbia SC

 1035 PM EST Wed Feb 24 2021

.SYNOPSIS...
High pressure over the area today will move offshore and away
from the region tonight as a weak cold front approaches from the
north. Clouds will increase Thursday with showers returning to
the forecast late Thursday night through Friday as Gulf moisture
overspreads the area. Friday will be a cool day but warmer
temperatures should return for the weekend. Showers will be
possible over the weekend and into early next week.

&&

.NEAR TERM /UNTIL 7 AM THURSDAY MORNING/...
A dry air mass will remain over the region despite surface high
pressure shifting east offshore giving way to an approaching
weak cold front that is moving into the Ohio Valley this
afternoon. Skies should remain clear through the night but there
is a forecast 25-30 knot low level jet which should help keep
the boundary layer somewhat mixed, preventing ideal radiational
cooling. The modification of the air mass combined with mixing
overnight will result in warmer overnight lows generally in the
mid 40s. May have some better cooling over the CSRA, which will
not have such a strong low level jet and therefore a more
stable airmass.

&&

.SHORT TERM /7 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
Thursday: Weak cold front with limited moisture moves into the
area tomorrow which will lead to some clouds developing during
the day but low levels remain dry. This front will limit warm
advection across the area but still expect a warm day. Once
again favored MOS consensus which has performed best with highs
the past few days and it hasn`t really been close. Highs in the
upper 60s to mid 70s is consistent with our local max
temperature scheme as well. Thursday night, moisture will
continue to increase across the area with flow aloft shifting
southwesterly. Isentropic lift will increase in the western area
but backed off a bit on rain until Friday morning with low
levels still needing to moisten up.

Friday: Increasing isentropic lift across the Piedmont Friday
leading to rain developing early which will reinforce weak wedge
conditions, especially in the NW forecast area. The entire area
will be much cooler with increased clouds with highs in the 40s
in the wedge and low 60s in the southern forecast area.
Shortwave moves through Friday afternoon with moderate rain
possible, although amounts will be higher to the NW. SREF mean
remains around a third of an inch in the Piedmont and a couple
tenths in Columbia, although there is still considerable spread.
Rain should taper off Friday night as the upper energy pushes
north and a ridge begins to build over the area.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Models continue to favor a strengthening ridge over the area
this weekend with MOS trending warmer and NAEFS showing heights
in the 90th percentile across the area. With the increase in
the amplitude of the ridge, the stalled boundary to the north
will have limited effects on much of the area. Have trended
drier for Saturday as a result. With SW flow in this deeper
ridge, moisture will continue to increase into Sunday with
ensemble members in good agreement in PWATs rising to above an
inch across the entire forecast area. While forcing will likely
be limited, cannot completely rule out rain with moisture so
high, especially in the north closer to the front. Considerable
uncertainty beyond the weekend as this boundary begins to slip
south. With plenty of moisture there will likely be a decent
batch of rain early next week but timing is very uncertain,
evident by the spread in the NBM. Also uncertainty as to if the
front stalls or pushes through the area which will impact both
temperatures and precip chances through midweek.

&&

.AVIATION /04Z THURSDAY THROUGH MONDAY/...
VFR conditions to continue for the TAF period.

As high pressure continues to remain anchored over the region,
clear skies will continue through Thursday morning. The breezy
conditions we saw earlier this afternoon have died down and
winds will remain light out of the southwest overnight.
However, with fairly strong low level flow of 30 knots at 1k
feet, some LLWS is expected overnight. Currently, guidance and
AMDAR soundings suggest that the LLWS will not be strong enough
to meet TAF thresholds, but its something to be aware of.

For Thursday, as a weak cold front approaches the area, some
scattered cloud cover at roughly 15k feet is expected to develop
by mid-morning. Winds will generally stay around 5 knots during
the day, out of the southwest in the morning and becoming
northerly as the front passes in the afternoon. No precipitation
is expected from this front but a broken deck around 10k feet
should develop along with the frontal passage. Despite the weak
front, conditions are expected to remain VFR through Thursday
evening.


EXTENDED AVIATION OUTLOOK...Increasing confidence for
restrictions Friday through Sunday as the front stalls and
shortwave passes across the region.

&&

.HYDROLOGY...
River and reservoir levels continue falling with a couple area
rivers remaining above minor flood stage. Levels will continue
slowly falling over the next couple days.

&&

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

&&

$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
HYDROLOGY...