159
FXUS62 KCAE 011824
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
224 PM EDT Mon Jul 1 2024

.SYNOPSIS...
A cold front will move south of the area this afternoon and
tonight. Slightly cooler and drier air will spread into the area
through Tuesday. Moisture will slowly increase across the area
mid to late week. High pressure building aloft by mid to late
week will result in well above normal temperatures by the
weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
KEY MESSAGES:
- Scattered showers and storms expected this afternoon in the
  eastern and southern Midlands.

Surface ridging is building across the Mid-Atlantic, pushing a
back door front across the area from the northeast as of 18z,
with distinct cool and dry advection filling in behind in NC and
northeast SC. Dew points across NC are now in the low 60`s and
50`s in most spots with PWAT`s down below 1.0". Enough moisture
however is lingering across the area ahead of the front to
support some showers and thunderstorms in the eastern Midlands
and CSRA throughout the afternoon and evening, but should remain
fairly isolated; instability is very limited as is any sort of
notable low-mid level shear, so the severe threat is low. Gusty
northeast winds are expected throughout the afternoon thanks to
strong mixing immediately ahead of and behind the front. Cool
dry advection overnight will yield the coolest temps in quite
some time with morning lows in the mid-upper 60`s.


&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
KEY MESSAGES:
- A brief respite from the heat and humidity.

Tuesday and Tuesday night...The upper trough will be off the New
England and Mid Atlantic coast with an upper ridge to our west
across the lower Mississippi Valley. The front appears to move
south of the area and drier and cooler air will advect south
from North Carolina. Precipitable water decreases to less than
an inch in the northern Midlands to near 1.5 inches south. RH
values 35% north to near 60% south. The Nam model is much
cooler than other guidance mainly due to considerable low
cloudiness. Think these clouds are a little overdone, but clouds
may linger in the southern areas until drier air spreads south
in the afternoon. So went with a consensus incorporating the NBM
25th percentile temps. This gives me mid 80s across the region.
The air mass appears mainly stable in the afternoon and think
at most, an isolated shower is possible in the southeast
Midlands and CSRA. But cut pops from previous forecast and
overall NBM pop guidance. Overnight temps near or slightly below
normal, 65 to 70 degrees.

Wednesday and Wednesday night...The upper ridge will be building
east across the area and expect subsidence to increase. Moisture
appears tor remain quite low across the region although late in
the day, precipitable water increases in the Piedmont around
850mb ridge. Air mass appears stable. So, expect temperatures to
warm a bit to near normal values and any showers should be quite
limited. Lowered the pops to mainly less than 15 percent, i.e.,
below the NBM mean pop.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
KEY MESSAGES:
- Heat and humidity returns back to the region as high pressure
  aloft rebuilds once again.

The upper ridge builds across the area and precipitable water
increases again to near or above 2 inches, especially by the
weekend. High confidence we will be at least reaching heat
advisory criteria by Saturday and possibly excessive heat
conditions as max temps reach 100 degrees or a little higher. As
moisture increases late week and the Piedmont trough sets up to
provide some low level convergence, expect an unstable air mass
leading to scattered mainly diurnally driven thunderstorms. The
upper ridge shifts to the coast over the weekend as a series of
low amplitude trough move from the northern Plains across the
Great Lakes/Upper Mississippi Valley. This will push a weak
front toward the area, possibly moving into the area Monday.
Ensembles are showing precipitable water > 2 inches by Sunday as
moisture flux increases ahead of the frontal system. Chance of
afternoon and evening thunderstorms possibly increasing a bit as
the front approaches.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
VFR conditions likely at all TAF locations through the period.

A back door front is pushing in from the northeast, forcing some
showers-storms to form across eastern SC. Some shower-storm
activity is possible near OGB later this afternoon and evening,
so continued a vcts mention through 00z at OGB. Gusty winds
likely ahead of and behind the approaching backdoor front,
gusting up to 15-20 knots. There will not be much in the way of
a wind shift however, with winds out of the northeast ahead of
and behind the front. Otherwise a scattered 4-6k foot cu deck
will linger throughout the afternoon for all sites. Some stratus
is likely Tuesday morning but should remain VFR.

EXTENDED AVIATION OUTLOOK...Morning stratus and afternoon
shower- storms likely Wednesday and each day through the end of
the week.

&&

.FIRE WEATHER...
KEY MESSAGE(S):
-Increased Fire Danger mid to late week.
-Rainfall probabilities remain relatively low mid week.

Increased fire danger during the Independence Day Holiday week,
especially late week as temperatures rise again to well above
normal values. Scattered afternoon and evening thunderstorms
possible may aid current dry conditions.

&&

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

&&

$$