Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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FXUS62 KRAH 281642
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
1245 PM EDT SUN AUG 28 2016

.SYNOPSIS...
High pressure will persist over the region through today. An upper
level disturbance over the Atlantic will drift west toward the
Carolina coast through Tuesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
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
90s.

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.

&&

.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
lower 70s.


.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
period.

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 /18Z SUNDAY THROUGH FRIDAY/...
As of 1245 PM Sunday...

There is high confidence that VFR conditions will prevail across the
western Piedmont of central NC through Monday night as an area of
high pressure at the surface and aloft extends overhead. Surface
winds out of the northeast may be breezy at times Monday, gusting
between 14-18kts.

Along and east of the highway 1 corridor, periods of cloudiness will
occur, resulting in MVFR/IFR ceilings, with the lowest ceilings
expected between 09Z-15Z Monday. A few showers may skirt in vicinity
of KFAY and KGSB , and south of KRWI this afternoon through early
evening, and again Monday afternoon. The difference in pressure
between the high to the west and the approach of tropical depression
to our east will yield breezy northeast winds Monday of 10-14kts
with occasional gusts near 20kts.

The above conditions expected to occur again Tuesday. Forecast
confidence lowers for the remainder of the work week as model
guidance offering varied solutions concerning the approach of a low
pressure system from the south-southwest, and a cold front from the
nw. At this time, the risk of adverse aviation conditions appear
greater at KFAY and KRWI, and less so at KRDU, KGSO, and KINT.

&&

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

&&

$$
SYNOPSIS...BS
NEAR TERM...WSS
SHORT TERM...BS
LONG TERM...MWS
AVIATION...WSS


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