849
FXUS62 KRAH 291723
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
120 PM EDT Sat Jun 29 2024

.SYNOPSIS...
Bermuda high pressure will remain locked in over central NC this
weekend. A cold front will push through the area Sunday night into
Monday.  Post-frontal high pressure will extend into the southeast
Monday and Tuesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1057 AM Saturday...

Water vapor imagery this morning depicted a de-amplified ridge over
the southeast. Further upstream, a developing trough and associated
convection was evident over the Midwest/Great Lakes region. A weak,
convectively-enhanced short-wave currently over Missouri/Illinois
will progress east across the mid-Atlantic today.

The remotely-sensed MMIC-TPW satellite product depicted a pocket of
residual drier air over much of central NC this morning. This drier
air will lift northeast and offshore today, as flow turns more sly
with increasing PWAT expected to stream in from the west late
tonight. Void of upper forcing (shunted to the north), and strong
sfc forcing, showers/storm coverage should be limited and primarily
confined to the higher terrain today. A few showers and isolated
storms could trickle into the far western Piedmont this afternoon,
and perhaps a rogue sea-breeze cell further east, but overall it
should be mostly dry today.

Given the persistent sly flow today, temperatures should once again
reach the mid 90s.  However, given the exiting residual drier air,
think that the dew points could mix out a bit more than previously
thought later this afternoon (upper 60s).  As such, heat indices may
not officially reach Heat Advisory criteria, but should hover in the
100 to 105 range.  Given that these values will be quite close to
advisory criteria, and that the experimental HeatRisk product
depicts the "Major" category over much of central NC, will let the
current Heat Advisory ride this morning.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
As of 333 AM Saturday...

The heat and humidity peak, but with good chance of thunderstorms to
bring cooling relief late day and Sunday night.

High heat and humidity will be the rule of the day at least until
scattered thunderstorms begin to develop in the early to mid
afternoon. Heat indices may very well be higher Sunday than today if
the clouds/storms hold off until mid to late day (which appears the
case for the eastern areas). Temperatures will get an early start
given the lows expected to be near 80 at many locations. Actual
highs in the lower to mid 90s are expected, with heat indices
possibly 105-109 from Raleigh and Durham south and east through the
Coastal Plain and Sandhills. Heat indices may top out near 100 in
the normally cooler NW Piedmont region before the chance of storms.

Given the high heat and humidity, instability MLCapes 2000-2500 J/kg
should result increasing the chance of strong to locally severe
storms. However, the stronger flow aloft is generally limited this
far south and southwest. SPC has placed at least the NE quad of our
region in a slight risk, with a marginal risk over the rest of
central NC. The primary threat will be local damaging wind.

Showers and thunderstorms are likely Sunday evening, especially from
the Triangle Area south and east. Hopefully, this will bring some
cooling rain for areas that have had little rainfall in the past
month. It will be cooler Sunday night after the front and hopefully
rain pass the region. Lows in the mid 60s to lower 70s expected.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 205 AM Saturday...

Aloft, a trough will progress eastward through the Northeast and mid-
Atlantic Mon/Mon night, while the mid-level anticyclone sits over
the ARKLATEX. As the trough moves away from the East Coast, the high
will once again build into the region from the west, sitting over
the TN Valley/Deep South Tue and Wed. A series of northern stream
s/w disturbances will track eastward through the northern CONUS Tue
through Fri, with each successive s/w slowly suppressing the high
southward. However, the high should generally remain over the
Southeast US through Fri. At the surface, the cold front should be
through NC Mon morning, with high pressure ridging into the area in
its wake from a high moving eastward through the Great Lakes. As the
high continues eastward through the Northeast and offshore Tue/Tue
night, it will continue ridging southward into central NC. Once the
high moves out over the Atlantic, a lee trough will develop, with
swly flow and the advection of warm, moist air into the area taking
over once again. Temperatures may actually be near to slightly below
normal Mon and Tue, but once the warm advection commences on Wed,
they will quickly rise back above normal Wed and remain above to
well above normal through the end of the week. As for rainfall,
aside from some possible lingering showers/storms in the east on
Mon, the next best chance for appreciable rainfall looks to be Fri
night.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
As of 120 PM Saturday...

VFR conditions will prevail through the 24 hour TAF period.
Scattered VFR stratocu (3.5 to 6 kft AGL) will cotninue to blossum
across the area this afternoon, but should dissipate with loss of
daytime heating this evening. Afternoon convection should mostly be
confined to the mountains and just inland of the coast, however a
stray shower/storm could trickle near KINT/KGSO later this
afternoon. Overall though, the forecast appears dry the next 24
hours.  Overnigh sub-VFR stratus should mostly be confined to the
mountains. However, some fleeting MVFR ceilings could migrate near
or at KINT/KGSO early Sunday morning. Confidence in this occuring is
too low at this time to include in the TAFs however.

Beyond 18Z Sunday: Showers and storms are forecast to develop ahead
of an approaching cold front Sunday afternoon and evening. Coverage
could develop as early as 18 to 20Z in the west, pushing east
through central NC into the evening hours. A few storms could be
strong to severe and cause strong downdrafts near or at our
terminals.  A secondary surge of showers/storms may be possible
along the passing cold front late Sunday night into Monday morning.
VFR conditions should return Tuesday and Wednesday as dry high
pressure extends into central NC. Dirurnal isolated showers and
storms will then be possible Wednesday and Thursday.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM EDT Sunday for NCZ008>011-024>028-
040>043-075>078-083>086-088-089.

&&

$$

SYNOPSIS...Luchetti
NEAR TERM...Luchetti
SHORT TERM...Badgett
LONG TERM...KCP
AVIATION...Luchetti