606
FXUS62 KCAE 061450
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
1050 AM EDT Sun Apr 6 2025

.SYNOPSIS...
Temperatures will be well above normal again today. A weak cold
front will sink into the Carolinas/Georgia this evening and
overnight. A secondary more significant front will move slowly
through the forecast area on Monday, bringing widespread showers
and possible thunderstorms. Much cooler temperatures expected
behind the front early next week before near average
temperatures are expected into next weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Key Message(s):

- Showers and thunderstorms will approach the FA late
  today/tonight
- Breezy conditions over area lakes today

10:45 AM Update: Radar is beginning to show some isolate light
returns in the imagery over the past 30 minutes or so. Not
entirely sure this is reaching the ground. However, SPC
mesoanalysis does indicate some moisture convergence and
isentropic lift in this area. So, it does seem reasonable if
some locations see some light rain. Guidance suggests this
chance for rain should be out of the area by early afternoon, so
have adjusted the grids to include a slight chance of showers
for the western half of the forecast area to reflect this.

Early-morning discussion: Early this morning, the KCAE VAD wind
profile shows a 40 to 45 kt LLJ a couple kft off the surface.
This will mix out this morning allowing wind gusts to pick up
shortly after sunrise. SW wind gusts of around 30 mph will be
possible this morning when the jet mixes down then again in the
afternoon as deep mixing develops ahead of a cold front. A Lake
Wind Advisory is in effect from 9 AM through midnight.

Upper level ridging over the Southeast will weaken today
allowing a trough over the central US to shift slightly east.
Ongoing convection along and ahead of a cold front will also
shift eastward through the near term. Outflow from this
morning`s convection could encroach on the western FA late this
afternoon and trigger additional showers and thunderstorms which
propagate eastward through the evening. However the main front
will still be well west of the FA through midnight and ridging
will still be in place into the early evening. This could hinder
additional development as the outflow progresses east. The
higher rain chances will be later tonight when ridging shifts
further offshore and the front itself moves into eastern GA and
the SC Upstate. PWAT values will likely exceed 1.7 inches
(greater than 250 percent of normal) across the western FA as
diffluent flow aloft strengthens. Strong forcing near the front
and deep moisture advection will support convection late tonight
into early Monday morning. Thunderstorms will be possible this
afternoon through the overnight but weak instability limits the
overall severe threat. Locally heavy rain may be the greater
threat given deep south-westerly flow parallel to the
front/outflow boundary and abnormally high atmospheric moisture.
Storms may train over the same area tonight leading to flash
flooding. Total rainfall amounts will generally range from 0.75
to 1.5 inches but the HREF localized PMM rain amounts point to
locally higher amounts of above 2 inches, especially in the
CSRA. Highs will be in the mid to upper 80s, well above normal.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Key Message(s):

- Showers and thunderstorms likely throughout Monday.
- Periods of heavy rain and a few strong to severe storms
  possible mainly into the afternoon hours.
- Cooler temperatures Tuesday.

Monday and Monday Night: An upper trough and the slow moving
cold front approach the region into Monday morning as 40-50 kts
of southwesterly to southerly flow at 850 mb sets up as well
with showers and possible thunderstorms moving in from the
northwest. EC ensemble and GEFS members continue to be
consistent in showing PWAT`s that reach nearly 250 percent of
normal throughout Monday with NAEFS IVT values approaching the
99th percentile into the afternoon. The best chance of
widespread rain showers and possible thunderstorms seems to come
from the late morning and into the evening where the front
begins to move into the FA and better synoptic forcing is
realized through upper divergence, increased 500 mb height
falls, and some PVA as the upper trough moves in as well. In
terms of severe thunderstorm potential, instability into the
morning hours seems rather meager with only a couple hundred
J/kg of MUCAPE, but as high res models have begun reach toward
early Monday afternoon, a tongue of MUCAPE values between
600-900 J/kg develops near the I-95 corridor, possibly extending
further north, just south of I-20, as steeper low and mid level
lapses rates are seen. The aforementioned LLJ and enhanced
500mb flow brings bulk shear values near 50-60 kts with up to
150-250 m^2/s^2 of sfc-1km SRH. This all suggests the greatest
risk for strong to severe storms will exist mainly south of I-20
and along the I-95 corridor starting in the late morning,
continuing into the early evening with the main risk being
strong wind gusts, though a low tornado risk is not out of the
question as shown in the SPC`s Day 2 Marginal risk (level 1 out
of 5) over the eastern CWA.

In terms of rainfall, not much has changed in the forecast as
the slow moving cold front, ample moisture, and enhanced
synoptic forcing from the late morning into the evening brings
expected QPF amounts between 1-2" where locally higher amounts
will be possible in areas with training showers/storms. This
training potential could bring possible localized flooding
concerns as well, but there is lower confidence at this time in
the exact location of training showers/storms. Temperatures vary
more across the FA with the cold front moving through with a
gradient from the low to mid 70s NW to the upper 70s in far
eastern spots.

Tuesday and Tuesday night: Morning temperatures start in the
mid to upper 40s as the front clears the area and upper
troughing begins to move out of the region with PWAT`s generally
under 0.50". Northwest to northerly flow and some cold
advection, keeps temperatures slightly below normal, in the mid
to upper 60s as we keep mostly clear skies. Surface high
pressure begins to slide just north of the FA into the evening
and overnight hours but some gradient winds and near 20 kts of
flow at 925 mb looks to keep winds elevated overnight. Besides
winds remaining elevated, strong radiational cooling conditions
are expected into Wednesday morning, allowing temperatures to
fall into the upper 30s, but if winds remain calmer than
expected, lower temperatures into the mid 30s could be possible.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Key Message(s):

- Temperatures near average expected through much of the
  period.
- Mostly dry until next rain chance toward end of period.

Weak upper ridging builds in for much of the mid week and
toward the late week as NAEFS PWAT values remain under 0.50" for
much of the period, leading to dry weather. Surface high
pressure north of the FA continues to slide out toward the late
week, keeping northerly to northeasterly winds and temperatures
that are below average Wednesday before reaching near average
for the rest of the period. Global guidance shows a sharp upper
trough digging in across the upper Midwest with a possible cold
front moving into the area toward Friday, bringing increasing
rain chances as moisture starts to increase ahead of this front.
As the trough slides over the northern Gulf into the weekend, a
surface response in the form of a coastal low riding up the
East Coast could be possible with the GFS operational runs being
the most aggressive with this solution, but there remains a
good amount of uncertainty in this.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
Mainly VFR for much of the TAF period.

OGB/AGS/DNL reporting MVFR/IFR cigs at the beginning of the TAF
period. Expect these cigs to continue, at least periodically,
through 14z. There is an outside chance these low cigs could
make it to CAE/CUB, but chances too low to include in the TAF.
In addition, a low level jet around 35-40 kts is being observed
via the VAD wind profiler, so there will likely be some LLWS,
but marginally meeting criteria at best. Once these clouds mix
out, VFR and breezy conditions expected this afternoon, with
south-southwest winds gusting to 20-25 kts. Gusts diminish
overnight, but sustained winds remain elevated due to an
approaching front. Rain showers, and potentially a few
thunderstorms, along with associated cig and vis reductions
start moving near the terminals around 02z with them becoming
more likely after about 06z.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...Lake Wind Advisory until midnight EDT tonight for SCZ016-018-
     020>022-025>031-035-037-041-115-116-135-136.
GA...Lake Wind Advisory until midnight EDT tonight for GAZ040-
     063>065-077.

&&

$$