Area Forecast Discussion
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FXUS62 KRAH 220600
Area Forecast Discussion
National Weather Service Raleigh NC
100 AM EST Wed Feb 22 2017
High pressure extending along the East Coast will move offshore
tonight. A slow-moving upper level trough will cross the Southeast
and Mid Atlantic states through Wednesday night.
.NEAR TERM /THROUGH TONIGHT/...
As of 950 PM Tuesday...
Cloud cover continues to increase across the area overnight in
advance of split mid level trough to the west of the area. However,
with the main energy aloft expected to pass to the south of central
NC, coupled with a dry low and mid level air mass to start, expect
only small chances for rain overnight. The best chance of rain is
expected across the far west/northwest piedmont where we may see
some spotty waa showers in advance of a mid/upper level low tracking
across the deep south. With gradually increasing and thickening
clouds from the west to east, expect lows will generally range from
the mid to upper 40s NE to the lower 50s SW (with maybe even a few
mid 50s far SW).
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
As of 650 PM Tuesday...
The light low level flow from the E and SE will keep low level
moisture streaming into the area, banked up against the higher
terrain, resulting in partly (east) to mostly (west) cloudy skies
Wed. Forcing for ascent remains fairly weak, as the weak mid level
flow limits DPVA. Moist isentropic upglide will also be weakening
through the day, confirmed by GFS precip progs showing a batch of
morning precip over the NW Piedmont shifting ENE across VA where
upglide will be deepest. The very weak and shallow moist upglide
will persist through Wed night, with stratus, patchy fog, and a risk
of drizzle or very light showers, particularly over the west. But
models continue to generate very little to no precip over most of
our CWA as the weakening mid level shear axis shifts to our east and
850 mb flow decreases and become more westerly, yielding a stagnant
column with plentiful moisture in the lowest few thousand feet.
Aside from good chance to low-end likely pops in the extreme NW Wed
morning, expect fairly low chances for much of the area from midday
Wed through Wed night. Expect areas of fog to develop late Wed night
as dewpoints steadily climb. With thick cloud cover lodged over the
NW Piedmont Wed and greater sunshine over the east with continued
very warm thicknesses, we`ll see wide-ranging highs Wed, from around
60 NW to the lower 70s SE. Lows Wed night around 50 to 55. -GIH
.LONG TERM /THURSDAY THROUGH TUESDAY/...
As of 300 PM Tuesday...
Thursday is starting to look pretty dry as a low pressure system
moves across the Florida Peninsula and into the Atlantic. A low
pressure system to the west is slower to develop then model
solutions showed over the last several iterations. This leaves
central NC in a moisture gap for much of the end of the work week
with both Thursday and Friday looking drier and fairly warm with
highs in the low to mid 70s on Thursday and in the mid to upper 70s
As the parent low makes its way to the Great Lakes region it will
push a cold front eastward over the Appalachians and into central NC
on Saturday/Saturday evening. The tail end of the moisture moves
across the state with northern areas of the forecast area more
likely to get rain than southern areas. QPF looks very meager on the
raw model output but there will be some instability around and if
some showers or thunderstorms were to form some areas could locally
see up to a half of an inch of rain but this is likely to be the
exception rather than the rule. Thus not as much help to the
abnormally dry situation as we had hoped.
While Saturday will still be warm ahead of the front with temps in
the mid to upper 70s, the airmass does modify on Sunday and high
temps drop back near 60 degrees which is much closer to normal this
time of year. Temperatures will modify back through the 60s on
Monday and back towards the 70s on Tuesday with dry conditions
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --As of 100 AM Wednesday...
24-Hour TAF period: Somewhat of a low-confidence TAF forecast the
next 24 hours. However, the expectation is for fog/low stratus to
develop across the east around 08-10Z and in the north and west
around 09-12Z. Cigs could drop into the LIFR range though visbys are
expected to remain MVFR or VFR. The duration of sub-vfr cigs and the
extent of improvement beyond the 12-15Z time frame is variable
across the area, but expect the best chance for and greatest
improvement to be at KFAY and KRWI. KINT and KGSO could remain MVFR
through late in the TAF period. The best chance for light rain will
also be at KINT and KGSO through the overnight and into early
Wednesday afternoon. The greatest uncertainty/variability will
likely be at KRDU, but will keep the trend there closer to that of
KFAY and KRWI for now.
Looking ahead: With continued southeast flow through Friday, the
early-morning sub-VFR cigs and visbys will likely be a reoccurring
theme. Low clouds may scatter out enough during the daytime hours
for a return to VFR. Winds will slowly veer through the period ahead
of the approaching cold front. Showers and sub-vfr conditions will
also be possible ahead of the front, which is expected to move
through Central NC on late Saturday. A return to VFR conditions is
expected for Saturday night/Sunday.
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