Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC-- Highlight Changed Discussion --
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FXUS62 KRAH 080751
Area Forecast Discussion
National Weather Service Raleigh NC
251 AM EST Thu Dec 8 2016
Weak high pressure over the Carolinas will weaken and shift east
tonight. An arctic cold front will move through the area Thursday,
followed by an expansive arctic high for the weekend.
.NEAR TERM /THROUGH THURSDAY MORNING/...
As of 750 PM Wednesday...
The warm and more moist advection from the southwest has already
become evident over NC, especially just above the surface through 5k
feet. Cirrus and cirrostratus were also increasing in the fast flow
up at jet stream level from the Tennessee Valley. Either cloudy or
becoming cloudy will be forecast for the rest of the night. We will
also raise temperatures a few degrees given the dew points were
already in the 40s outside of the NW Piedmont (30s). Lows generally
should bottom out in the lower to mid 40s as the clouds thicken up.
There may be some light fog; however, with the increasing stratus it
appears that widespread or dense fog is not likely at this time.
Other than a minimal chance of some very light rain or sprinkles,
there appears to be little in the way of mechanisms to produce
anything more that some shallow lift for measurable rain. Expect
only a few hundredths in the western Piedmont by 12z.
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
As of 320 PM Wednesday...
Any light warm advection driven precip Thursday morning will
shift east and may consolidate or become a little more showery as
fgen strengthens and the cold front sweeps across the area.
Northwest flow and increasing cold advection will clear skies by
midday to early afternoon, though the brunt of the cold advection
will likely be delayed until later Thursday night. Highs should
reach the low to mid 50s.
Strong CAA will continue Thursday as expansive Arctic high begins
east into the region. Overnight will fall into the mid 20s to
upper 20s with a steady wind near 10mph and wind chills in the
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --As of 245 AM Thursday...
Expect highs on Saturday to be similar to Friday, albeit a few
degrees warmer, as arctic high pressure centered over the region
begins to modify. The latest 00Z GFS/ECMWF guidance remains as
divided as previous runs with regard to the timing/evolution of the
next shortwave/surface low/cold front anticipated to approach the
Carolinas from from the west early next week. Since long range
guidance has failed to converge on a similar solution thus far for
Sunday/Monday, forecast confidence remains well below normal. As
such, little change will be made to the long term forecast (Sun-Wed)
at this time. -Vincent
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.AVIATION /06Z THURSDAY THROUGH MONDAY/...
As of 1230 AM THURSDAY...
Weak/shallow upglide/WAA ahead of an arctic cold front that
will move through the area between 12 to 18z Thursday will result in
the development of IFR to MVFR CIGS areawide between 06 to 12z.
Some patchy/spotty light rain is also possible, but MVFR VSBYS
should be the lowest category forecast.
Strong post-frontal low-level dry cold air advection will clear out
the Sub-VFR ceilings from west to east between 12 to 18z. Expect
sustained west-northwest winds to 8-12kt, with gusts into the 18 to
22kt range, strongest in the west.
Outlook: VFR conditions are expected through the weekend. The next
chance of sub-VFR conditions will be early next week.