Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS62 KRAH 300646
Area Forecast Discussion
National Weather Service Raleigh NC
245 AM EDT TUE AUG 30 2016
Tropical Depression Eight will approach the Outer Banks of North
Carolina later today or tonight, before lifting northeastward into
the Atlantic Wednesday. A cold front will approach from the
northwest Wednesday, then push southeastward through North Carolina
on Thursday. Cool high pressure will start to build into the area
from the north Thursday night and Friday, as what is now Tropical
Depression Nine tracks northeast off the Southeast coast.
.NEAR TERM /THROUGH TONIGHT/...
As of 950 PM Monday...
TD 8 continued to be located about 150 miles SE of Cape Hatteras
moving slowly NW this evening. However, little
if any strengthening has been noted per the latest Intermediate
Advisory issued at 800 PM by the NHC.
Otherwise, the mean flow around the mid level low located off of the
GA coast and high pressure to our north continued to be from the NE.
A low level dew point boundary was pinned down in the SE Coastal
Plain with higher pressures and dry air inland.
The area of showers and a few thunderstorms that tracked SW across
the SE Coastal Plain again this afternoon has dissipated. Only a few
clouds lingered in the wake of these showers in the SE, with mainly
partly cloudy to mostly clear skies elsewhere.
With the dew points lower or drier tonight by 2-5 degrees compared
to those of 24 hours ago, especially over the Piedmont, we may see
more lows in the 60s over the northern Piedmont by daybreak.
Otherwise, expect partly cloudy to mostly clear skies. Lows 62-72.
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
As of 135 PM Monday...
Moisture will increase over central NC on Tuesday as an E/NE onshore
flow expands westward across the state, with PWAT values rising in
comparison to today as , the shear axis extending N/NNW into the
area (from a stalled upper level low offshore the GA/FL coast) today
is expected to shift W/SW into western NC, upstate SC and northern
GA. As a result, forcing will largely be absent Tue/Tue night. In
fact, subsidence is likely to be present over portions of central/
eastern NC on the western periphery of TD #8 Tue aft/eve (progged to
be a marginal tropical storm by then) as it approaches the NC OBX.
With the above in mind, will indicate a dry forecast over central NC
Tue/Tue night, with the best chance for precip along the Carolina/
Southeast coast. Expect partly cloudy skies with highs in the upper
80s to near 90F. Lows Wed in the upper 60s to lower 70s. -Vincent
.LONG TERM /Thursday through Monday/...
As of 245 AM Tuesday...
Thu/Thu night: Precip concerns for NC Thu/Thu night include a low
pressure area projected by some models to be just off the southern
NC coast early Fri, as well as the cold front approaching from the
NW, driven by a digging northern stream trough swinging through the
St. Lawrence valley and Northeast states. The former feature, if it
occurs, is likely to impact only our far SE sections (where PW will
be higher) early in the day, while the latter should bring a broken
band of showers and a few storms across the entire CWA later in the
day and into the evening, a result of marginal instability and deep
layer shear, upper divergence in the right entrance region of the
jet extending from northern VA to the Canadian maritimes, and low
level mass convergence and moisture pooling ahead of the front. But
coverage should be limited somewhat by the preceding low level
downslope component to the low level flow. Will keep a pop in the
far SE early, then retain a trend up to good chance pops Thu
afternoon, trending down in the late evening and overnight from NW
to SE. Highs 87-92 on the last day of above-normal temps prior to
frontal passage. Lows 65-70.
Fri-Mon: The circulation around what is now TD9 may pull a few
tropical showers into our far SE Fri as it tracks toward the NE off
the SC/NC coast, along with enhanced surface winds and gusts from
the northeast. But otherwise our weather heading into the weekend
will be largely driven by the cool high pressure building in from
the north, pulling in below-normal thicknesses and a markedly drier
air mass that will last into Mon, albeit with some modification as
the mean weak trough eases eastward just off the East Coast as
heights build in the west due to the building mid level ridge
through the Miss Valley and Ohio Valley. Weather may remain a bit
unsettled over the eastern CWA near the baggy upper trough axis, but
otherwise will have a dry forecast. Highs mostly in the lower-mid
80s and lows in the lower-mid 60s. -GIH
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
As of 130 AM Tuesday...
24 hour TAF period: VFR conditions should prevail for most of the
TAF period but there will be the usual period of MVFR stratus
possible, especially from KRDU eastward. This should be fairly short
lived and conditions will return to VFR a little after sunrise.
Northeasterly winds will remain in place for the duration of the
TAF period at 5-10 kts.
Long Term: Fairly dry conditions for much of the week with the
biggest threat for showers and thunderstorms in the extreme eastern
locations. A better chance for sub-VFR conditions near the end of
the week as what is now tropical depression nine makes a pass to