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000
FXUS62 KRAH 191433 CCA
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
1030 AM EDT Fri Apr 19 2024

.SYNOPSIS...
A weak backdoor front over northeast North Carolina will slowly lift
back north as a warm front this afternoon. A cold front will cross
the region late tonight into early Saturday, and then settle just to
our south late Saturday. A wave of low pressure will track along the
front Sunday into Monday, bringing unsettled conditions and cooler
temperatures.

&&

.NEAR TERM /TODAY AND TONIGHT/...
As of 1030 AM Friday...

...Isolated strong to severe storms remain possible this afternoon
and evening...

There has been little change in previous thinking with only minor
adjustments to ongoing forecast. While confidence in the coverage
and precise timing of the shower/storm chances is lower than usual,
confidence is high that impacts will be localized/isolated in
nature.

Complicating the forecast was last night`s back-door cold frontal
passage, which can be identified by the leading/western edge of a
< 1000kft stratus layer that has advanced westward into the western
Piedmont and western Sandhills. This shallow layer of cooler and
drier air may delay the northward retreat of the aforementioned
front to the north and the northward expansion/development of
instability across the area, especially if we see any light
precip/rain into the stable layer as the lead precip band
moves east.

Speaking of a lead precip band, a band of pre-frontal showers, which
is associated with a sheared vorticity axis moving through the area,
has just traversed the mtns and will move east into the western
Piedmont over the next few hours. Initially instability is absent,
but as the warm front lifts north and as we get into peak afternoon
heating, weak to moderate buoyancy, maximized generally south of HWY
64, should lead to an increase in convective coverage and intensity
over central and eastern NC during the afternoon and evening.
Enhanced by pockets of dry air in the mid levels(owing to w-nwly
flow aloft), favorable DCAPE central NC will make isolated wind
damage the primary threat, followed by marginally severe hail.

Closely on the heels of the lead convection, another area of showers
and storms accompanying the arrival of the cold front into the area
will move in from the NW towards sunset and will progress across the
area through 06z. Will also have to monitor these storms for severe
potential but loss of heating and increasing BL CIN should result in
weakening intensity and coverage, with largely dry weather expected
after 1 or 2 AM.


Expect highs today to range from lower/mid 70s NE to mid/upper 80s
SW, followed by upper 50s to mid 60s for lows.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
As of 350 AM Friday...

The weekend will start out partly to mostly cloudy before becoming
mostly cloudy to cloudy with slight rain chances easing in. The cold
front will have pushed into our SE sections by Sat morning and will
progress SSE, settling into N SC as low pressure drifts southward
into the SC Midlands. A much cooler air mass will gradually build
in, although the most dense air will initially be held up by the
higher terrain, allowing for good afternoon mixing and highs that
will be cooler but still a bit above normal, in the 70s with near 80
in the far S. Despite the westerly mid level flow on the S side of
the broad trough, PW across the S and SE, near the surface front,
will remain elevated, at or over 1" through Sat night, as the
noticeably cooler air finally pours in from the NNW. While forcing
for ascent is largely quite weak or even absent heading into Sat
night, we will see slowly improving moist upglide across the south,
up and over the low level frontal zone, resulting in a reinforcing
of low level stability and groundward moistening of the column,
necessitating low chances for light rain, mainly S of Hwy 64,
starting late Sat going through Sat night. Lows from the upper 40s
N to upper 50s S. -GIH

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 219 AM Friday...

Sunday: Flow aloft turns swly Sunday and Monday increasing low-level
moisture advection into the southeast. Ensembles and deterministic
guidance are in pretty good agreement at this point pinning a sfc
cold front, instability, and the highest anomalous moisture along
the coastal areas and offshore. Rain chances will still increase
throughout the day Sunday (highest POPs still across our far
southeastern zones) but primarily light to moderate stratiform rain
is expected through Monday morning. Sfc flow will remain nnely,
promoting a cool, wet, and breezy day with highs in the upper 50s to
lower 60s. QPF ranges from a few tenths of an inch (N) to about a
half of an inch (S).

Monday through Thursday: Any lingering rain Monday morning will pull
off to our east by early afternoon.  A few additional scattered
showers may be possible Monday afternoon/evening with the passing of
a strong vort max, but overall Monday should largely be dry. Tuesday
will follow suit under nwly flow aloft.  By Wednesday, a sheared
vorticity feature will ride through the Mid-Atlantic. This may spawn
a few scattered showers, but overall coverage should be minimal. Dry
weather continues under nwly flow aloft on Thursday.

Temperatures Monday will remain cooler than normal be cool in the
mid 60s. Temps will rise into the mid 70s Tuesday through Thursday.

&&

.AVIATION /12Z FRIDAY THROUGH WEDNESDAY/...
As of 645 AM Friday...

INT/GSO: VFR conditions are likely to hold through the next 24 hours
at INT/GSO, with clouds thickening early this morning and remaining
largely broken through this evening, but with VFR bases. Isolated
showers are possible from late morning through mid afternoon (15z-
19z) at INT/GSO, followed by a potential for isolated storms into
early evening (19z-02z) as a cold front approaches. Shower/storm
chances will end by mid evening, as the front pushes to the E.
Surface winds will be light, under 10 kts, starting from the NE
before shifting to SE, then SW, then NW after nightfall behind the
front.

RDU/RWI/FAY: These sites will see continued IFR to low-end MVFR
stratus early this morning, lasting through much of the morning,
until around 15z, with the longest duration at RWI and a slightly
earlier end at RDU/FAY. VFR conditions are expected to return by
17z, but with thickening clouds. Isolated showers are possible
starting in the mid afternoon (mostly after 18z), with a few
thunderstorms possible from mid afternoon through late evening
(mainly 20z to 03z), ending thereafter with dry conditions expected
after 05z tonight. Another round of MVFR to IFR conditions is
expected across the NE and E late tonight (starting around 05z)
through Sat morning, particularly affecting RWI/FAY. Surface winds
will be light and variable, under 10 kts.

Looking beyond 12z Sat, after mostly dry weather Sat (except a
slight rain chance at FAY) as the front settles just to our S, a
wave of low pressure tracking along the front will bring a high
chance of sub-VFR conditions and rain from Sun afternoon through
early Mon. Rain chances may linger esp at FAY Mon night, but
otherwise VFR conditions are expected Mon through Tue. Showers and
storms are possible Wed ahead of a cold front. -GIH

&&

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

&&

$$

SYNOPSIS...Hartfield
NEAR TERM...CBL
SHORT TERM...Hartfield
LONG TERM...Luchetti
AVIATION...Hartfield