Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC-- Remove Highlighting --
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FXUS62 KRAH 022349
Area Forecast Discussion
National Weather Service Raleigh NC
649 PM EST Fri Dec 2 2016
High pressure will build southeast from the northern Plains this
afternoon, reach the Ohio Valley Saturday, then extend down the
eastern seaboard Sunday. A coastal front will develop late in the
weekend through Monday, as a storm system takes shape over Texas
into the western Gulf Coast region.
.NEAR TERM /THROUGH TONIGHT/...
As of 140 PM Friday...
Sunny skies are expected this afternoon. High pressure over North
Dakota will continue to build SE with CAA over the the eastern
states including NC. The high pressure will be slow to reach the
eastern seaboard, only doing so by Saturday night and Sunday. This
will prolong the cool dry conditions for NC. Highs are expected to
reach the mid 50s to around 60, warmest in the Sandhills and far
southern Piedmont zones. A NW breeze at 10-15 mph will add to the
coolness of the air, diminishing to less than 10 mph by sunset.
Other than a few cirrus from time to time, mainly southwest, clear
skies are expected tonight. Due to the distance of the high pressure
from our region tonight, optimal radiational cooling is not expected
through the evening with at least some mixing through midnight, give
or take a few hours. Then calm conditions should allow excellent
radiational cooling late tonight. Lows generally 28-35, coldest in
the rural Piedmont.
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 145 PM Friday...
Timing of the approaching storm system that is expected to develop
over Texas and the NW Gulf of Mexico is still expected Sunday night
and Monday; however, as high pressure at the surface extends down
the eastern seaboard later in the weekend, moisture will return from
the Atlantic as a coastal front forms Saturday through Sunday. This
means increasing clouds and chilly temperatures Saturday into Sunday.
We will begin to increase the chance of light rain/drizzle with the
coastal front to the SE on Sunday afternoon and night. Depending on
how much QFP, cold air damming (CAD) will most likely develop Sunday
and linger as the system approaches early next week. We will trend
POP up Sunday afternoon and night and trend temperatures down below
guidance Sunday anticipating the development of CAD with the
cool/dry air initially in place aiding in it`s development. Many
Piedmont areas may stay in the 40s Sunday depending on timing
of rain and CAD development.
.LONG TERM /SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --As of 205 PM Friday...
A weak wave will move up the Carolina coast early Monday and
depending upon its track could bring some rain to central NC and
points east. The best chances for rain will be across the south and
east before a lull in precipitation on Monday afternoon and evening.
The real weather maker of the long term will be Monday night and
Tuesday with a Miller B scenario that will bring two lows out of the
deep south, one which will move up the coast and the other west of
the Appalachians and up through the Tennessee Valley. The upshot is
an extended period of rain Monday night and Tuesday with enough
dynamic to bring some heavier amounts to the area. That being said,
forecast soundings are very stable with a strong warm nose over the
area that will be hard to overcome so the threat for any thunder at
this time seems low but a change in the track of the coastal low
could change that. Warmer but a large temperature gradient across
the area with low 50s in the Triad to low 60s in the southeast.
Wednesday and Thursday will be tranquil and mild with clear to
scattered clouds. A few showers cross the region Thursday evening in
advance of a much colder airmass moving southeastward from the
central US. Precipitation should be well east of the area by the
time surface temperatures fall to or below 0C. 1000-500 mb
thicknesses in the 1510 to 1520 range on Friday so max temps will
be in the 40s. Minimum temperatures Friday night will be in the 20s,
perhaps in the upper teens in the Triad.
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.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --As of 645 PM Friday...
24 Hour TAF Period: VFR conditions are expected to continue through
the 24 hour TAF period as surface high pressure builds into the area
from the northwest. This will lead to generally a light west to
northwesterly wind tonight, with a northwesterly wind in the 5 to 10
mph range on Saturday. Some high level cloud cover will begin to
stream into the area on Saturday.
Outlook: VFR conditions are expected Saturday into Sunday. However,
medium confidence in lowering CIGS Sunday or Sunday night, MVFR to
possibly IFR conditions are possible as a coastal front develops.
Rain should hold off, but the chance of drizzle may develop over the
western Piedmont in the damming region around KGSO/KINT as early as
Sunday night. IFR VSBYS possible in these areas Sunday night, MVFR
to VFR VSBYS in the east.
Periods of MVFR to IFR CIGS and VSBYS expected Monday through
Tuesday depending on how quickly the storm system expected
to develop over the NW Gulf of Mexico spreads deep moisture into
NC. High confidence in rain/fog/low CIGS sometime early next
week. Timing still in question.
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