Chappells, South Carolina Weather Forecast Discussion

577
FXUS62 KCAE 211739
AFDCAE
Area Forecast Discussion
National Weather Service Columbia SC
139 PM EDT Sun Sep 21 2025
.SYNOPSIS...
High pressure builds into the region with above average
temperatures expected again on Sunday. Dry conditions continue
to start off the work week, then rain chances will be on the
increase from mid- week onward.
&&
.NEAR TERM /THROUGH TONIGHT/...
Key message(s):
- Dry with temperatures above normal today
Surface high pressure over New England will allow surface
ridging to extend along the East Coast and into the forecast
area. NE flow has pushed drier air into the FA than the
previous few days. This will hinder any convective development
this afternoon with rainfall unlikely. GOES derived PWAT values
over the region are from 1 to 1.2 inches, down from 1.5 inches
the day before. Highs will be a degree or two lower than
yesterday but still above normal with values in the mid to upper
80s. Low temperatures tonight will also a couple degrees
cooler, in the low to mid 60s.
Tonight, as surface high pressure lifts out of New England,
ridging over the FA weakens and low level flow into the
terminals becomes more easterly. This will usher in some low-
level moisture and the potential for low clouds and patchy fog.
A 20 kt low level jet (LLJ) tonight will favor stratus over fog.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Key message(s):
- Warm and mainly dry to start off the work week.
Another beautiful stretch of weather is expected to start off
the work week as we careen towards the end of astronomical
summer. Weak upper level trough axis will continue to work its
way northeastward during this period, gradually losing
amplification and being replaced by increasing heights by
Tuesday night. This weakening shortwave will allow the surface
ridging that is present across the area today to lose its punch
and shift eastward into the Atlantic. The result will be a
gradual shift in our low-level flow with southeasterly flow
gradually becoming southwesterly by early Wednesday. Despite a
modest, slow increase in PWs during this period, the upper level
pattern will remain unfavorable for widespread precipitation.
The only real chance may be Tuesday evening as the sea breeze
works its way into the coastal plain, aided by surface onshore
winds. Highs will bump up from the upper 80s on Monday into the
low 90s on Tuesday as heights begin to slowly rise over the
area. Lows should remain in the mid 60s.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Key message(s):
- Rain chances return for mid to late week.
- Above normal temperatures through Thursday, then turning
  cooler.
Deep troughing is forecast to develop across the central US,
shifting into the eastern CONUS gradually as the period
progresses. Deep southwesterly flow is shown by global models
and their ensembles, with PWs continuing to rise ahead of the
approaching trough and surface front. PWs by Thursday and Friday
are forecast to rise up into the 140%-160% of normal range
(~1.8"-2.0") which will foster showers and thunderstorms both
THursday and Friday as the front slowly moves through the
region. Ahead of this, temps are forecast to be quite warm, with
highs possibly in the mid 90s on Wednesday as heights rise into
the 588dm range. Thursday could see temps approach this level,
but potential clouds and rain showers cloud whether or not temps
will get that warm on Thursday. Friday through Sunday looks to
feature more normal temps, though there is significant
uncertainty in this period. Guidance is very mixed on what
happens with the deep, amplified trough as it pushes into the
southeastern US. We have had a tendency towards cut off lows
recently, so my hunch is to think that may happen with this
trough. However, the spread amongst teleconnections forecasts
makes larger scale forecasting in this timeframe difficult as
well, so it is hard to say that forecaster confidence beyond
Friday`s forecast is any higher than low at this point. It does
look like next weekend should favor temps nearer to normal but
really lacking confidence to say much more than that at this
time.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Restrictions possible again tonight.
NE flow has pushed drier air into the forecast area than the
previous few days. This will hinder any convective development
this afternoon with rainfall unlikely. Winds today will be out
of the NE through the day. A 20 kt LLJ tonight will make
widespread fog less likely. However as surface high pressure
lifts out of New England, ridging over the FA weakens and low
level flow into the terminals becomes more easterly. This will
usher in some low-level moisture and the potential for low
stratus or fog. The HRRR which performed well with the deck of
low clouds into eastern NC the previous night suggests IFR or
lower ceilings into eastern SC tonight. Given the recent
performance of the HRRR and the persistent restrictions at AGS
and OGB the past few days, we felt confident enough to include a
few hours of restrictions at the two sites. The other terminals
also could also experience ceiling restrictions if the stratus
pushes far enough inland. Restrictions should dissipate by 15Z
with ENE winds around 5 to 10 kts through the afternoon.
EXTENDED AVIATION OUTLOOK...Periods of early morning
fog/stratus remain possible, especially at AGS and OGB through
early next week. Moisture increases mid-week leading to
increasing chances for rain and widespread restrictions.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...None.
GA...None.
&&
$$

NWS CAE Office Area Forecast Discussion