Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC
FXUS62 KRAH 200612
Area Forecast Discussion
National Weather Service Raleigh NC
112 AM EST Fri Jan 20 2017
An upper level trough will pivot northeast across western North
Carolina into this morning. This will be followed by a brief quiet
period Friday afternoon and night. A strong storm system is expected
to affect the region over the weekend into Monday.
.NEAR TERM /OVERNIGHT/...
As of 935 PM Thursday...
Evening upper air analysis depicts a narrow ridge of high pressure
over the state. Immediately on the back side of the high, clouds
were thickening/lowering with patches of light rain developing over
the southern mountains. The ridge is expected to drift offshore
later tonight, leading to increasing cloud cover over our region,
with a good chance for light rain by daybreak across the western
Piedmont. At this time, the bulk of the rain should remain west of
the Triangle, and west of Fayetteville through 7 AM. Rain chances in
the Triangle and Fayetteville quickly reach their peak by mid-late
Mid evening temperatures varied from near 40 across the far
northeast to the upper 40s/around 50 over the far south and west.
As clouds thicken overnight, expect temperatures to hold steady or
rise a degree or two prior to the arrival of the precip. Min temps
will vary from the upper 30s/around 40 northeast to the mid 40s west.
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
As of 255 PM Thursday...
Rain is expected over the region Friday morning... tapering off
from the west during the afternoon. QPF will be highest in the NW,
lowest SE, ranging from around 0.25 NW to less than 0.10 SE.
Temperatures will remain rather cool or held down by the rain
and clouds. Light flow even behind the departing system will
generally yield cloudy skies with some breaks during Friday
Expect highs in the 50s north, lower to mid 60s south.
Friday night... Patchy fog and variably cloudy skies expected as
we will be between systems. The main issue is the potential
for dense fog if we get some partial clearing. Lows in the upper 40s
to mid 50s.
.LONG TERM /Saturday through Thursday/...
As of 230 PM Thursday...
A wet, but mild spell is on tap for the weekend into early next week
as a strong cutoff low pressure area digs into the Midwest and
across the Gulf states before lifting up the Atlantic coast on
Tuesday. Timing confidence is fairly high, while finer details of
potentially how much rain where are still somewhat murky. There
appear to be at least 3 distinct periods of potential showers as
this slow-moving system taps into the Gulf and feeds abundant
moisture north up the Atlantic coast. An initial short wave and
associated surface warm front will be lifting northeast, steered by
an upper ridge over the eastern seaboard on Saturday, with showers
spreading north into the area by afternoon and lingering through
Saturday night. Shower coverage may be a bit diminished on Sunday,
but mid level instability and upper dynamics (particularly upper
divergence in the exit region of a jet streak rounding the base of
the upper low) should support isolated thunder in the afternoon
through Sunday night. Finally, we should see some lighter, wrap
around showers linger through Monday into Monday night as the upper
low lifts out to the northeast.
All told, widespread rainfall amounts exceeding 1.5 inches are
expected over the 3 day period. Rain should be spread out enough
over the period to preclude any flooding on larger streams and
rivers, but some localized flooding in urban areas is possible given
the potential for stronger convection on Sunday and Monday. Highs
Saturday and Sunday will be in the 60s, cooling to mid 50s to lower
60s Monday in modest northerly cool air advection on the backside of
the low level circulation.
Cold air will remain bottled up over the northern Conus, so
temperatures will remain mild with as mid level ridging migrates
across the area Tuesday through early Thursday. Abundant sun will
help induce a bit of a warmup, with highs around 60 Tuesday warming
to the mid 60s on Wednesday. A cold front will be approaching on
Thursday, which looks to be mostly dry and we will still be shielded
from arctic sir in the wake of the front, so highs should still
reach the upper 50s to lower 60s.
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
As of 110 AM Friday...
24 Hour TAF period: VFR conditions across the area this morning
should remain so for the next few hours before ceilings start to
come down at the Triad sites in advance of a system that is expected
to track through the area later today. Expect MVFR after 9Z with IFR
following shortly after, closer to 12Z. Eastern sites will come down
a few hours later from west to east. Short term models show
precipitation moving into the Triad around 12z and losing intensity
as it crosses the northern tier. This will leave some question as to
whether or not KFAY will see any rain or not. Other sites to the
east still should see some light rain late morning through early
afternoon before the system quickly moves out to the northeast.
Conditions should begin to improve thereafter.
Long term: Expect fog early Saturday morning and then attention
turns to a stronger system expected to bring the possibility of
thunderstorms to the area on Saturday. Conditions should return to
VFR on Sunday.