212
FXUS62 KCAE 301819
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
219 PM EDT Sun Jun 30 2024

.SYNOPSIS...
Hot and humid conditions continue, with afternoon and evening
showers and thunderstorms this afternoon through the evening
ahead of an approaching frontal boundary. The front is expected
to bring slightly cooler and drier conditions to start off the
work week, but building high pressure will allow the return of
temperatures near the century mark by mid to late week.

&&

.NEAR TERM /THROUGH TONIGHT/...
KEY MESSAGES:
- Heat Advisory in effect during the afternoon and early
  evening.
- Scattered to numerous showers and thunderstorms possible this
  afternoon/evening ahead of a cold front.

Scattered cumulus is developing ahead of an approaching front
and we steadily destabilize early this afternoon. Water vapor
imagery clearly shows the approaching shortwave aloft, and some
evidence for a deformation was seen earlier. THis deformation
likely helped strengthen a mid-level cap and keep cloud cover
suppressed longer than expected this morning-afternoon, so
temps jumped up near 100 F in many spots. Convection has mostly
remained across NC early this afternoon as the strongest
synoptic forcing has pushed north, but convection will steadily
become more widespread over the Midlands later this afternoon.
Hi-res guidance is doing a decent job thus far and generally
shows between 1000-1500 ML CAPE developing within a very weak
shear regime during the mid- afternoon and evening. So while
coverage should be fairly widespread this evening, the severe
potential should remain isolated with little-no organization
expected. Convection should fall off quickly after 00z,
lingering a bit longer in the eastern Midlands and coastal
plain.


&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
KEY MESSAGE(S):
- A brief respite from the heat and humidity.

Monday and Monday night...Upper trough centered over the
northeast CONUS will shift off the coast by evening. The strong
upper ridge over the southern Plains will begin to build back
east. At the surface, the frontal boundary will be near the
southeast Midlands in the morning then shift slowly to the
south as dry air spreads south from North Carolina. Near the
front, precipitable water is expected to be at or above 2
inches. Precipitable water will be much lower across the
northern Midlands...in the 1.0-1.5 inch range by afternoon. CAM
models suggest scattered showers will develop in the moderately
unstable air mass near the front by mid morning and slowly shift
south and east during the afternoon. Focus for more widespread
convection should be in the coastal plain near the sea breeze
and frontal convergence by later in the afternoon. Area in
general cold advection so, max temperatures should be
significantly cooler than previous days...in the 85 to 90 degree
range with lingering cloudiness into into the afternoon and
cooler at night with lows into the mid to upper 60s.

Tuesday and Tuesday night...The latest GFS/ECMWF suggest the
front will move a little further to southeast with moisture
mainly confined to the coastal plain. Lowered the pops a bit
especially across the central and northern Midlands where based
on the grand ensemble guidance and deterministic models, the
precipitable water is likely to be less than 1.5 inches. Weak
easterly/north-easterly flow supports cooler temps, mid to upper
80s and lows in the mid to upper 60s.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
KEY MESSAGES:
-Heat and humidity return as high pressure aloft rebuilds.
-Rainfall probabilities remain relatively low.

Ensembles indicate the anomalously strong upper ridge...up to
about 2 standard deviations above normal...over the Midwest
will build east over the area during the mid to late week
period. This will result in well above normal temperatures,
NBM max temperature guidance is around 100 degrees each day into
next weekend. The probabilistic guidance shows 50% or higher
chance of max temperatures in excess of 100F both Friday and
Saturday with increasing moisture. Isolated diurnal convection
should develop primarily near the remnants of a frontal boundary
on Wednesday and then primarily near the sea breeze front
Independence Day through Saturday. The ridge appears to weaken
by next weekend as another front approaches the area, so
scattered showers/thunderstorms expected as moisture increases,
especially by Sunday.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
VFR conditions expected through the early afternoon before
shower-storms likely at all sites.

Scattered 4-6k foot cumulus is developing across the region
this afternoon ahead of an approaching front. Scattered showers
and thunderstorms are expected to develop between 18-20z,
becoming more widespread from 21z onward. VCTS and a tempo TSRA
group are mentioned for all TAF sites through this time period.
Winds outside of these showers-storms will remain fairly light,
up to 10 knots from the south. Storm activity will cease after
02z across the area and widespread stratus is likely to develop
for all TAF sites overnight into Monday; confidence is shaky on
whether LIFR conditions will occur, but IFR conditions are
expected for all sites.

EXTENDED AVIATION OUTLOOK...Shower and storms likely across the
coastal plain, possibly impacting OGB Monday afternoon.
Additional stratus and afternoon shower-storms likely Wednesday
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 and precipitation chances remains relatively low.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...Heat Advisory until 7 PM EDT this evening for SCZ016-018-
     020>022-025>031-035-037-038-041-115-116-135>137.
GA...Heat Advisory until 7 PM EDT this evening for GAZ040-063>065-
     077.

&&

$$