Area Forecast Discussion
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FXUS62 KRAH 021849
Area Forecast Discussion
National Weather Service Raleigh NC
140 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/...
As of 335 AM Friday...
Sunday is expected to be a dry and cold day with high pressure to
the north eventually moving offshore by Sunday night and although
weak, could end up being an in-situ damming situation by Sunday
night into early Monday morning. Highs sunday only in the upper 40s
to low 50s. Lows Sunday night in the upper 30s to lower 40s.
On Monday a weak wave will move up the Carolina coast 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 night. Highs in the mid 50s and lows
in the low to mid 40s.
The real weather maker of the long term will be Tuesday and Tuesday
night 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 on 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.
The rain will end Tuesday night and Wednesday and Thursday should be
drier with highs near 60 degrees.
.AVIATION /18Z Friday through Tuesday/...
As of 1230 PM Friday...
High confidence in VFR conditions for the next 24 hours. NW winds
10kt this afternoon will diminish to less 5kt tonight.
Looking beyond 12z Sat: VFR conditions are expected Saturday into
Sunday. However, medium confidence in lowering CIGS Sunday or Sunday
night, MVFR to possibly IFR 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.