Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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FXUS62 KRAH 241354

Area Forecast Discussion
National Weather Service Raleigh NC
955 AM EDT MON OCT 24 2016

A dry cold front will cross central North Carolina later this
afternoon. High pressure will build over the area tonight and remain
through the mid-week period.


As of 955 AM Monday...

The cold front expected to drop south-southeastward through NC later
today is currently analyzed just south of the Ohio River and Mason-
Dixon line, denoted by little more than a shift in surface winds and
perhaps a slight cooling (the notably cooler/drier air is still back
over WI/MI, behind a diffuse reinforcing front). The air mass
preceding and along the front is quite dry, noted on both WV imagery
and upstream upper air data, with stable mid levels, and model
projections of no precip with this front -- and only some high thin
clouds -- appears validated. Winds just aloft at 850 mb have been
rather brisk from the WNW at 25-35 kts overnight, especially across
our north, and this deep flow from the WNW to NW has contributed to
the overall drying. The presence of some high level moisture in
tandem with the also-favorable vertical thermal and kinematic
structure has fostered orographically enhanced cirrus clouds,
although these should be on the decline as winds aloft weaken a bit
with increasing lapse rates aloft with heating/mixing. Based on warm
thicknesses around 15 m above normal and good insolation today, have
nudged up highs to 74-79. -GIH

Previous discussion from 623 AM: A cold front over the Ohio Valley
ATTM will drop SE this morning and uneventfully move across central
NC during the mid-day or afternoon hours. With dry conditions
prevailing both pre-and post-fropa, look for mostly sunny conditions
with temps climbing into the mid 70s before fropa.  For tonight,
high pressure will begin building into our area from the NW in the
wake of the front. Clear skies and cool temps with lows in the lower
to mid 40s.


As of 310 AM Monday...

High pressure and dry conditions will provide fair weather during
this time.  Temps will run a few deg below normal in the wake of
Monday`s front.  Highs in the mid 60s and lows in the lower 40s.


As of 340 AM Monday...

Dry and slightly unseasonably cool high pressure ridged down the
Atlantic coast lingers but begins to weaken on Wednesday.
Meanwhile...a rather low amplitude upper trof moves east across the
Great Lakes/Ohio Valley with its associated surface frontal system
approaching on Thursday. Low level flow veers around southerly ahead
of the front, with associated moisture and warm air advection
conspiring to produce showers in the west early Thursday and across
central NC during afternoon and evening. The strongest upper forcing
remains north of the area as we remain on the wrong side of the
upper jet, but do see low level wind directional convergence
focusing rather narrowly over the eastern CWFA late day...
coincident with the best...albeit nearly-anemic instability. Will
refrain from mention of rumbles amidst the showers, but will
modestly increase PoPs in the east. Highs Wednesday and Thursday
will be in the mid to upper 60s...with some lower 70s south on
Thursday due to longer duration of the warm air advection.

Heights build a bit for Friday and Saturday, with highs mostly from
70 to 75 ahead of a reinforcing short wave approaching Sunday which
will produce a weak shot of cool air advection and keep highs mostly
in the upper 60s.


As of 623 AM Monday...

Latest KRAX VWP shows llws relaxing, and expect this to further
improve after sunrise, thus will remove it from our 12z tafs.
Otherwise, VFR conditions will continue through the TAF period under
mostly clear skies. Westerly SFC winds will gust between 15 to 20kt
in advance of a dry cold front passage this afternoon, then becoming
north to northeast tonight and gradually diminishing.

Beyond 12z Tuesday through Friday...the next chance for sub-vfr
conditions will be Thursday, assoc with the passage of the next cold
front, which will have more moisture and better chance for rain.
Otherwise, VFR conditions expected.




NEAR TERM...Hartfield/np
LONG TERM...mlm is the U.S. government's official web portal to all federal, state and local government web resources and services.