Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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FXUS62 KRAH 290805
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
405 AM EDT WED JUN 29 2016

.SYNOPSIS...
A cold front will progress through central NC this morning, stalling
near the coast in the afternoon. The front will begin to return
northward as a warm front on Thursday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 330 AM Wednesday...

Updated to add Dense Fog Advisory through 9 AM.

The deep moisture plume has pushed offshore southeast of the area,
with thinning of the high cloudiness. The clear and calm conditions
induced widespread fog development over the eastern half of the
state - basically areas which received rain Tuesday. Meanwhile, the
effective surface front will creep across the area early this
morning, drying out the low levels as dew points fall to the mid
60s. Broad troffing aloft with predominantly westerly flow will
induce lee troffing to assist mostly sunny skies to push highs up to
mostly upper 80s.

Both ECMWF and GFS feature a weak short wave riding the mid level
flow across the area tonight, perhaps providing enough lift to
squeeze out some showers and isolated thunder, especially in the
southeast where moisture and instability will be a little more
available. Mins will be persistence, ranging from mid 60s across the
north to 70 across the southern tier.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
As of 330 AM Wednesday...

The moisture boundary southeast of the area will be drawn inland
across the southern coastal plain in the wake of the departing short
wave on Thursday. The southwest-northeast surface trof alignment
will be parallel to the mid level flow to provide a favorable
environment for enhanced convection induced by downstream impulses
which take the easy route up the coast. Will raise PoPs to ~50%,
weighted higher towards the southeast where instability will be
enhanced by the moister atmosphere. Shear will be modest, but return
of the 2 inch PW plume and steepening mid level lapse rates could
produce isolated wet downbursts approaching severe limits. A better
defined short wave will be lifting northeast across the area early
Thursday night, which will maintain at least chance PoPs overnight.
Highs on Thursday will range mainly from 85 to 90...with mins
Thursday night mostly in the upper 60s.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 330 AM Wednesday...

Primary storm track will remain well removed from the area, with
mid/upper level energy tracking east along the US-Canadian border
through the long term period. The broad/weak mid/upper troughiness
over the region on Thursday will get replaced with low-amplitude,
quasi-zonal flow aloft by the weekend and continuing. At the
surface, a nearly stationary surface boundary/trough will reside
invof the Carolinas and will serve a focus for mainly diurnal
convection Friday and Saturday.

For several runs now, both the GFS and EC are showing surprising
good agreement in the depiction of a series of mid/upper levels
disturbances/possibly MCS activity embedded in this low-amplitude
flow that will attempt to increase coverage/convective rain chances
and potentially lead to periods of heavy rain from training
convection by late Saturday and continuing into early next week. The
quasi-stationary surface boundary should finally shift east of the
by mid-week, leading to drier conditions.

With the surface boundary stalled over the area, temperatures should
be at or slightly before normal.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
As of 330 AM Wednesday...

24-hr TAF Period: Expect IFR to LIFR conditions to persist through
12-13Z in areas that received rain yesterday, which includes the
RDU/RWI/FAY TAF sites. This low level moisture will mix out with VFR
conditions for the remainder of the TAF period, with some MVFR fog
possible towards sunrise Thursday morning in the eastern sites.

Thursday onward - broad cyclonic to near zonal flow aloft will
dominate the weather pattern through the weekend. As such, there
will be a chance of mainly diurnal, late afternoon/evening,
convection followed by late night morning stratus/fog in locations
that are affected by convection the day prior.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 9 AM EDT this morning for NCZ007>010-
024>027-040>042-075>077-085-086-088.

&&

$$
SYNOPSIS...CBL
NEAR TERM...MLM
SHORT TERM...MLM
LONG TERM...CBL
AVIATION...MLM


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