Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC-- Remove Highlighting --
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FXUS62 KRAH 281425
Area Forecast Discussion
National Weather Service Raleigh NC
1025 AM EDT SUN AUG 28 2016
High pressure will persist over the region through today. An upper
level disturbance over the Atlantic will then drift west along the
Carolina coast Monday and Tuesday.
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --As of 1025 AM Sunday...
Little change required to the near term forecast.
Patches of low clouds/stratus have begun to erode. This should lead
to mostly sunny or partly cloudy skies at most locations by mid day.
12Z upper air analysis depicts an area of high pressure at the
surface and aloft extending sw-ne across most of the western
Piedmont. Subsidence associated with this feature should inhibit
convective development later this afternoon. In the east, low level
analysis depicts a weak trough and attendant weak moisture
convergence along the eastern periphery of our forecast area. This
should aid in the development/maintaining isolated to scattered
convection later this afternoon. Best threat for a shower or storm
should be confined to locations east of I-95, and more so in
vicinity of Goldsboro and Clinton.
850MB temps are about 3 deg C cooler compared to same time Saturday.
This supports afternoon temps a solid 5-7 degrees cooler than
Saturday. This yields max temps this afternoon near 90 to the lower
A steady east-ne confluent onshore flow aided by the approach of a
developing tropical depression off the NC coast will result in
variably cloudy skies and a threat for showers along the east-se
fringe of our forecast area. Otherwise expect mostly clear-partly
cloudy skies elsewhere. Overnight temps near 70-lower 70s.
-- End Changed Discussion --
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 400 AM Sunday...
Monday looks fairly similar to today, with the upper low drifting
inland over SC and briefly stalling. A strong moisture gradient
will set up again with the surface ridge and deeper mixing in
the west, and better moisture/instability over the coastal plain.
A weak offshore surface low drifting toward the NC coast will have
little impact here, and scattered showers and a few storms will
again be confined to the southern coastal plain. Highs in the
upper 80s and lower 90s. Lows monday night in the upper 60s and
.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 226 PM SATURDAY...
WV imagery this morning depicts an increasingly well-defined mid to
upper level low off the SERN U.S coast. The forecast models continue
to indicate this feature will drift W --around the SRN periphery of
the initially strong sub-tropical ridge centered over the Middle
Atlantic states-- and stall along the SERN U.S.
coast early this week, before shearing out and lifting away from the
region through the middle of the week.
The presence of this mid-upper low, and a NRN stream trough forecast
to migrate across the NERN U.S through early week, will cause the
preceding sub-tropical ridge to succumb over the Middle Atlantic
states and ultimately split, with one center expected to retrogress
into the central U.S. and the other retreat into the central N.
Atlantic Ocean. A broad trough will develop between the two /over
ERN U.S./ through the end of the week.
This pattern aloft will play an important role in what becomes of
the now well-advertised tropical wave along the NRN coast of Cuba
this morning, which the models now generally agree will enter the
ERN Gulf of Mexico early to mid-week. Significant model spread
regarding the track and timing of the associated low develops
thereafter, though it seems reasonable that low will eventually be
influenced by the aforementioned ERN CONUS trough aloft and be drawn
NEWD through or along the SERN U.S coast, with an associated
increased probability of rain, through the end of the forecast
Of greater predictability will likely be a NRN stream cold front
forecast to settle through the SRN Middle Atlantic states and
Carolinas Thu-Fri, with an accompanying chance of convection
maximized in central NC Thu-Thu night. Cooler and drier conditions
in post-frontal high pressure ridging across the Middle Atlantic
region would follow, though the duration of this post-frontal regime
will hinge upon what happens with the tropical low and associated
moisture potentially approaching from the south later Fri and Sat.
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
As of 650 AM Sunday...
Stratus spreading westward from the coastal plain into the Piedmont
may reach RDU before starting to lift through the morning hours. RWI
and FAY, and maybe RDU, can expect LIFR conditions to slowly improve
to IFR and MVFR by 15z, with generally VFR conditions this
afternoon, outside of a few showers or isolated storms around FAY.
Tonight should be very similar to last night, with stratus spreading
across the area from east to west after 06Z, potentially making it a
little further west and increasing confidence of IFR/LIFR as far
west as RDU.
Outlook: VFR conditions will prevail during the daytime this week,
with early morning stratus/fog likely given continued easterly flow,
and the best chance of afternoon convection will be around FAY and