-- Discussion containing changed information from previous version are highlighted. --
597
FXUS62 KRAH 190550
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
150 AM EDT Sun May 19 2024

.SYNOPSIS...
A cold front will move south across southern NC and SC Sunday
morning. High pressure will follow and extend across the southern
Middle Atlantic through Tuesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 930 PM Saturday...

Surface observations as of 01z show a sharp theta-e gradient from
north to south as a front extending from near Charlotte eastward
towards Fayetteville and just south of Clinton and separates
temperatures in the mid 70s to the south from low/mid 60s to the
north. Regional radar shows mostly showers and isolated storms along
the front with trailing stratiform precipitation back into cooler
air behind the front. This front is expected to sag south through
04/05z and shift the lingering instability and associated showers
and storms out of the area while stratiform rain and an isolated
rumble of thunder may linger for a few more hours into the night. A
compact 500mb shortwave visible in WV imagery over the lower
Tennessee Valley will slowly pivot east-southeast and support
continued showers along the front through the night, but should
mostly be south of the forecast area.

Areas of low overcast may continue to lower through the night and
lead to some patchy fog, most likely in the northern Coastal Plain
into portions of the Northeast Piedmont. Expansive low cloud cover
will keep over night temperatures relatively steady through the
night behind the front with lows in to low 60s to upper 50s.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
As of 220 PM Saturday...

By Sunday morning, surface low pressure should be off the NC/SC
coast with a positively tilted upper trough axis extending across
the Delmarva Peninsula through North Carolina into northern Georgia.
Both the surface low and the upper trough will move east through the
daytime, with the trough axis near the Atlantic coastline by the
evening. High-resolution and synoptic models have continued the
trend from the last couple days of showing drier conditions overall.
It now appears that locations north of US-64 should be dry through
the day, with a slight chance of showers to the south of that and a
chance of thunderstorms along the southernmost border. Any
precipitation should come to an end by the evening, with dry
conditions overnight. The upper trough will help to keep conditions
mostly cloudy through the morning, then at least some partial
clearing will occur during the afternoon. Northeasterly flow should
occur through the day, becoming lighter overnight, but the cold
advection on the backside of the surface low should make Sunday the
coolest day out of the next seven. Some locations across the
northeast should remain in the upper 60s, but otherwise highs will
be in the lower 70s.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
As of 134 PM Saturday...

Monday through Wednesday: Aloft, the trough should be offshore, with
the sub-tropical ridge building from the southern plains to the
Northeast US early Mon. While the trough should linger off the mid-
Atlantic coast through Wed night, the ridge will shift slightly
sewd, extending from the lower MS Valley to the mid-Atlantic by 12Z
Wed. The ridge axis will generally remain over the area through at
least Wed night, albeit continuing to drift sewd. At the surface,
the ridge will remain in place through Mon night, while the low
sits/drifts eastward offshore. The surface high will settle south
over the mid-Atlantic coast through Tue before drifting eastward
over the Atlantic, but continuing to ridge westward toward/into the
area, on Wed. A warm front may lift northward through the area Wed
as the high moves away, with a lee trough strengthening over the
area Wed night. While Mon should be largely dry, there is still the
possibility for a brief period of lingering light rain early.
Otherwise, the forecast through Wed night is currently dry. As for
temperatures, there some continued uncertainty in highs on Mon, but
for now expect low/mid 70s east to upper 70s west. Lows should
generally be in the low to mid 50s Mon night. Expect temperatures to
moderate through mid-week.

Thursday onward: A northern stream low will track enewd through the
western Great Lakes and into Ontario Canada Wed/Thu. The ridge will
be suppressed sewd Thu/Fri as a s/w tracks from the mid-MS Valley,
enewd into the northern mid-Atlantic/Northeast US. This wave may
briefly amplify the larger scale trough over the Northeast and mid-
Atlantic Thu night/Fri. There is the potential for showers/storms
across the area with this disturbance Thu/Thu night. Meanwhile,
another s/w will move through the southern/central Plains Thu,
through the mid-MS Valley Thu night/Fri, then enewd through the
Appalachians Fri/Fri night. There are still some timing/location
difference between the medium-range model solutions, so those
details remain unclear. However, there will be another chance for
showers/storms with this system if/when it track through the mid-
Atlantic/Carolinas Fri/Sat. Expect continued near to above normal
temperatures through Sat.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
As of 150 AM Sunday...

Widespread, generally IFR ceilings throughout cntl NC this morning
will lift through MVFR after 14-15Z and scatter to VFR from
northwest to southeast - first at INT/GSO and latest at FAY.

Looking ahead: After a return to VFR conditions this afternoon,
lingering boundary layer moisture could result in sub-VFR cigs again
late tonight and Mon nights. Otherwise, expect largely VFR
conditions Mon through Wed. The next chance for sub-VFR conditions
will be Thu/Thu night with cold front and associated chance of
showers and storms.
-- End Changed Discussion --

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...MWS
NEAR TERM...Swiggett
SHORT TERM...Green
LONG TERM...KC
AVIATION...MWS/KC