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692
FXUS62 KRAH 050144
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
944 PM EDT Tue Jun 4 2024

.SYNOPSIS...
A series of mid-level disturbances will move east and interact with
an unseasonably moist airmass over NC through Thursday. A pre-
frontal trough and cold front will move across the area Thursday
evening through early Friday.

&&

.NEAR TERM /TONIGHT/...
-- Changed Discussion --
As of 944 PM EDT Tuesday...

Shower/tstm activity coverage has decreased during the past couple
hours with loss of heating...however radar continues to show several
outflow boundaries and very isold showers along those boundaries
slowly moving across parts of central NC.  Meanwhile, we`re keeping
our eyes on the cluster of tstms moving across upstate SC and the
far western NC Piedmont.  While the intensity is trending down with
that activity, some of the CAMS suggest what`s left of it crossing
parts of central NC during the late overnight or pre-dawn hours.
That said, while the shower coverage right now appears to be on the
decrease, we`re going to keep at least slight chance PoPs across the
western and central parts of our CWA overnight due to the
aforementioned features.  It`s also worth noting that recent water
vapor loop hints at a weak MCV on the southern end of that cluster,
so another reason to keep PoPs going overnight as that feature moves
east tonight.  Lows tonight within a couple deg of 70.
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
As of 225 PM Tuesday...

Upstream MCVs will continue to influence central NC`s sensible
weather during this period as Bermuda high pressure remains in
control.

The first MCV, currently over central TN, will likely traverse
central NC during the 1st half of the diurnal cycle. Isolated to
widely scattered weak convection is possible as this feature moves
through the area during what is otherwise poor diurnal timing.

In the wake of the lead MCV, possible remnants of another MCV
associated with the linear cluster over NE TX and lower MS Valley,
could potentially move through the area during peak afternoon
heating, with re-development of showers and storms from west to east
across the area during the afternoon and evening. Deep layer shear
increases slightly, but is still weak, and should mitigate the
severe threat. Mean storm motion should also be higher than recent
days, but given moist PWATs of 1.9-2.0", some localized flash
flooding remains possible. Isolated to widely scattered
showers/storms could linger overnight, especially with renewed lift
from an elongated shortwave trough extending south from the mid-
latitude cyclone over southern Ontario.

Highs into the mid 80s to around 90 F, with some lower 80s possible
over the NW Piedmont where the second round of convection could pop
off earlier. Lows in the mid 60s to lower 70s with areas of stratus
expected.


&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
As of 305 PM Tuesday...

An oblong upper low will be positioned from Manitoba through
southern Ontario and Upper Great Lakes Thurs morning with an
occluded surface low stacked underneath over Ontario. Enhanced
southwesterly flow centered around 850mb will overspread central NC
through the early morning into the evening hours with boundary layer
mixing supporting 20-30 mph wind gusts, highest in the Coastal Plain
into the Sandhills. A weakening ribbon of vorticity is forecast to
spread from the southern Appalachians Thur morning through the
Coastal Plain by the evening hours. This band is expected to produce
a narrow band of showers/storms traversing across the forecast area
with a deepening trend as it overlaps with better pool of
instability over the Coastal Plain into the Sandhills. Despite
increased flow around 850mb, flow aloft is rather weak with central
NC displaced southeast of the better dynamics aloft. This will
result in relatively weak deep layer shear with a majority of the
speed shear confined to the lowest 3km. This may result in loosely
organized clusters tracking along the lead cold front. Severe threat
predictability is low at this time, but sub-severe wind gusts and
small hail in the deepest updrafts certainly seem possible through
the early evening hours.

A reinforcing cold front will move through Thurs night into Fri
morning and will bring in drier air with dew points falling to the
50s by Fri afternoon. Deep layer moisture will dry out with PWATs
falling to around 0.8 inches (approaching the 10th percentile for
GSO) and will lead to a dry and more comfortable forecast for Fri
through Sun. Steady moisture advection from the west and southwest
with periods of troughing over the eastern CONUS will bring back
mostly diurnal chances for showers/storms for early next week.
Behind the cold front, temperatures will generally waver around near-
normal values.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
As of 725 PM Tuesday...

Generally VFR conditions will continue outside of widely scattered
showers and thunderstorms through around midnight. Some low stratus
and fog will be possible between 09z and 15z, mainly in areas that
had heavy rain on Tuesday (KRDU and KGSO/KINT).

Outlook: Scattered showers and thunderstorms associated with a cold
front that is expected to come through the region late Wednesday
Thursday will result in flight restrictions of MVFR or lower in some
areas. VFR conditions are expected to return Friday through the
weekend before another disturbance moves into the region early next
week.

&&

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

&&

$$
SYNOPSIS...MWS
NEAR TERM...np
SHORT TERM...CBL
LONG TERM...Swiggett
AVIATION...Badgett/CA