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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KRAH 250809
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
409 AM EDT Thu Apr 25 2024

.SYNOPSIS...
As the cold front settles off the Southeast US coast today, cool
high pressure will slowly ridge southward into central NC through
tonight. The surface ridge will remain over central NC through
Friday night slowly shifting east and south through the weekend.

&&

.NEAR TERM /TODAY AND TONIGHT/...
As of 315 AM Thursday...

As of the 06Z surface analysis, the cold front was about halfway
through central NC, between the Triad and Triangle. The front should
continue sewd through the area over the next few hours and be
offshore by daybreak. An area of low pressure is expected to develop
along the front off the Carolina coast today, but should remain
offshore. In the wake of the front, winds will become nely, with
cool high pressure ridging into NE portions of the area during the
day, then continue sswd through the area overnight as the surface
high settles sewd over the Northeast US. Expect largely dry weather
across central NC through tonight, however an isolated shower invof
the southern Coastal Plain cannot be completely ruled out later this
aft/eve should a seabreeze develop and drift that far inland. Expect
low stratus to develop across the area as boundary layer moisture
increases in NE flow off the Atlantic. Additionally, with increased
isentropic lift as relatively warm, moist air advects into the area
over the cool surface ridge, clouds may also develop in the 700mb to
850mb layer. Some high clouds could also develop as a weak
disturbance aloft tracks SE through the area tonight. Highs today
should range from mid 60s over the northern Coastal Plain and along
the NC/VA border to mid/upper 70s along the NC/SC border. Tonight,
increasing cloud cover and stirring should inhibit radiational
cooling, however with CAA and low-level thicknesses in the 1340m to
1360m range, expect lows to bottom out in the low 40s NE to low 50s
south.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
-- Changed Discussion --
As of 345 AM Thursday...

A sub-tropical high will strengthen from the Gulf of Mexico nwd and
across the Southeast this period. Immediately preceding the
associated ridge axis, a 700 mb-centered warm front, and "warm
advection wing" accompanying a cyclone that will lift across the
cntl Plains and upr MS Valley, will overspread the OH Valley and srn
Appalachians on Fri and srn Middle Atlantic and Carolinas Fri night.

At the surface, strong/1030-1035 mb, cP high pressure will build
from srn QC swd and across New England and the nrn Middle Atlantic
coast, with associated temperate enely flow directed across cntl NC.

A veering wind profile from enely at the surface through nwly in the
mid-levels, and associated implied WAA, will contribute to the
development and maintenance of a layer of high-based stratocumulus
over particularly the NC Piedmont this period. Meanwhile, a band of
Fgen, WAA, and saturation accompanying the 700 mb warm front noted
above will spread enewd and across cntl NC between 00Z-12Z Sat,
during which time the associated lift may sufficiently deepen the
combined saturated layer to support patchy light rain over the nw NC
Piedmont. A slight chance of rain has been introduced there Fri
night to account for this possibility.
-- End Changed Discussion --

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
As of 400 AM Thursday...

A mid/upr-level anticyclone and ridge will build across and offshore
the South Atlantic states through Monday. A weak shortwave trough
will then briefly weaken the ridge as it migrates across the ern US
Tue-Tue night, followed by a re-strengthening and retrogression of
the sub-tropical ridge across the lwr MS Valley and Deep South
during the middle of next week.

At the surface, cP high pressure will continue to migrate swd along
and just offshore the Middle and South Atlantic coasts through early
next week. As the high drifts swd and steadily modifies, it will
direct seasonably mild ely flow across cntl NC Sat and much warmer
sswly flow Sun-Wed. A pre-frontal/lee trough and following cold
front will then accompany the aforementioned shortwave trough over
the ern US late Tue-Wed. Associated probability of showers/storms
should be diurnally-maximized with the pre-frontal/lee trough, which
will likely move across the srn Middle Atlantic Piedmont and Coastal
Plain Tue afternoon and evening, with dry conditions in cntl NC
until that time. It appears at this time that the synoptic cold
front may not reach cntl NC, and instead only the pre-frontal trough
and perhaps outflow will do so and settle across the forecast area
by Wed morning. As such, continued well above temperatures are
likely to persist Wed, as will a slight chance of diurnal convection
given the presence and proximity of the lee trough and outflow that
may linger from Tue afternoon-evening convection.
-- End Changed Discussion --

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
As of 135 AM Thursday...

24 hour TAF period: Some IFR vsbys have developed over the eastern
half of central NC, with KRWI the only TAF terminal experiencing
restrictions as of 06Z. LIFR cigs and vsbys are expected at KRWI
later tonight. The question is if this will impact KRDU and/or KFAY
as it spreads west-southwestward tonight. For now will continue to
hint at the possibility in the TAFs at KRDU and KFAY, but will wait
until confidence increases to include lower restrictions. Otherwise,
expect VFR conditions to dominate through the TAF period. Winds will
become nely to ely Thu/Thu eve in the wake of the front, increasing
into the 6-10 kt range at times. A stray shower over the Coastal
Plain will be possible, but given the low confidence in occurrence
will leave out for now.

Outlook: Sub-VFR conditions are expected Thu night into Fri morn and
possibly again for a brief period during the pre-dawn hours Sat
morn. Otherwise, largely VFR conditions are expected through Mon.
There is also a non-zero chance for some patchy light rain, mainly
in the Triad, Fri night/Sat, otherwise generally dry weather is
expected through Mon.

&&

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

&&

$$
SYNOPSIS...KC
NEAR TERM...KC
SHORT TERM...MWS
LONG TERM...MWS
AVIATION...KC