Scientific Forecaster Discussion
fxus62 krah 230559
Area forecast discussion
National Weather Service Raleigh NC
155 am EDT Fri Jun 23 2017
low pressure will pass by to our northwest, crossing the central
Appalachians Friday night into Saturday morning, before moving off
the mid Atlantic coast. This will drag a trailing cold front through
our area late Saturday through Saturday night. High pressure will
follow bringing cooler and drier air into our region for next week.
Near term /through 12z/today/...
as of 155 am EDT Friday...
A large area of showers with locally heavy rain is expected to move
NE across western and northern NC through 12z/today. Since the air
mass is increasingly tropical with dew points well into the 70s and
pw's 2+ inches, some locally heavy rain with rainfall of 1+ will
likely occur. It appears that the heaviest rain should affect the
foothills from hky to mwk, but may also affect parts of the northwest side
of The Triad including Winston-Salem. We will have categorical pop
in the NW, ranging to 30 pop in the southeast through 12z. Very little
lightning was noted with this large area of heavy showers due to the
low topped convection in the tropical air mass. We will omit
thunderstorm chances at this time. Lows 68-73 northwest to southeast.
Short term /Friday/...
as of 323 PM EDT Thursday...
The plume of high >2.0" precipitable waters over the Carolinas briefly lifts
away from the area, before a secondary surge late Friday night
and Saturday as the remnants of Cindy approach from the west. There
will also be a void in forcing over the region on Friday as well,
with only insolation and the inland retreating seabreeze boundary
acting on the continued moist/muggy low-level airmass. Will have
a small chance/scattered pops across the southeast, otherwise
After extensive morning stratus, highs should rebound quickly in the
warm sector reaching the lower 90s se, with mid to upper 80s northwest.
Breezy SW winds to 20-25 miles per hour.
Long term /Friday night through Thursday/...
as of 323 PM EDT Thursday...
The lower/mid tropospheric remnants of Tropical Storm Cindy are
forecast to become increasingly sheared and will accelerate
northeastward through the southern mid-Atlantic states early Saturday as it
gets picked by the westerlies ahead of the northern stream trough
digging into the central US.
With the remnant circulation/pv anomaly associated with Cindy
expected to pass north, so will the heavy rain/flooding threat, with
quantitative precipitation forecast amounts having decreased significantly across the
area. Instead, a concentrated area of warm moist advection, along the
leading edge of a 800 mb 50kt llj, will fuel a band of showers and
thunderstorms into western NC, that will weaken as they progress
eastward into the central and eastern Saturday morning as the
better support aloft lifts off to the northeast. Convective
re-development is then expected during the afternoon
and evening, as the lead cold front moves into the area, before
stalling near the coast Saturday night into Sunday. Scattered
in the west, to possibly numerous showers and storms in the
east are possible Saturday afternoon, with a few strong to severe
storms possible in the east. Additionally, with the front forecast to
stall out, some localized/isolated flooding is possible as storms
train along the stationary boundary.
A stronger disturbance aloft in the cyclonic flow across the eastern
half of the country is expected to approach and move across the area
early next week, along with an associated cold front. This will give
US another chance for some showers and storms on Monday into Monday
night, along with a push of drier and cooler air, with highs by
Tuesday possibly struggling to reach 80 across the Piedmont and some
low temps dropping into the mid to upper 50s by Wednesday morning.
Aviation /06z Friday through Tuesday/...
as of 155 am Friday...
Showers with IFR conditions expected at kgso and kint over to krdu
through 12z/today, with IFR ceilings at kfay and krwi. Showers will end
from the SW between 09z-12z but IFR conditions will linger through
15z or so. MVFR ceilings will become VFR between 18z and 21z with a
gusty SW wind at 15-25kt.
Looking beyond 00z Sat (fri evening), scattered showers and
thunderstorms with a gusty SW wind at 15-25kt are expected Fri
evening, lasting into Sat morning, with prevailing sub-VFR
conditions late Fri night through daybreak Sat.
Generally VFR conditions will return saturday; however, MVFR
conditions with scattered showers and storms are expected from krdu
eastward Saturday afternoon and evening. Then a return to VFR
conditions are forecast Saturday night through early next week with