035
FXUS62 KRAH 081820
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
120 PM EST Fri Nov 8 2024

.SYNOPSIS...
A back-door cold front will sag slowly south across NC through the
afternoon and early evening. High pressure will build into the area
from the north tonight and Saturday. Moisture will begin to
overspread the area from the west Sunday, ahead of a cold front that
will move through the area Monday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 950 AM Friday...

The Dense Fog Advisory was allowed to expire. The forecast otherwise
remains unchanged from below.

Previous discussion issued at 200 AM Friday...

Limited by the very dry mid and upper levels, latest hi-res model
guidance continues to depict isolated showers and/or sprinkles this
morning and through the afternoon as the front slips south. So far,
convection has been next to none. Thus, reality is under performing
and that will likely be the case until mid to late morning, when
weak buoyancy develops via tempered heating/insolation.

Low-level post frontal dry air advection will lead to north-south
scouring out of the morning fog and stratus. Highs today ranging
from mid/upper 70s across the north, with lower 80s elsewhere.

Substantial sfc pressures and CAA from the north will get underway
tonight. While this will be a marked cool down from the past several
days, lows tonight will still average 7 to 12 degrees above normal.
Lows ranging from mid/upper 40s north to lower/mid 50s south.

&&

.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
As of 200 AM Friday...

Aloft, the amplifying sub-tropical ridge will progress eastward
through the eastern US Sat/Sat night, while a low lifts newd from
the central Plains to the upper MS Valley. At the surface, high
pressure will continue ridging swd through the area Sat/Sat night as
the center of the ~1029mb high progresses esewd from the eastern
Great Lakes through the Northeast US. Expect the weather to be dry
Sat/Sat night. Temperatures should be near to slightly above normal,
with highs in the low/mid 60s NE to upper 60s SW. Lows are a bit
trickier, as increasing cloud cover Sat night may dampen the degree
of radiational cooling. Low level thicknesses are forecast to be in
the 1340-1355 meter range (from NW to SE), with generally calm to
light winds, especially across the north and northwest. For now,
expect lows generally in the low mid 40s, with some upper 30s
possible in the usual cooler spots and where the clouds are latest
to fill in.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 240 AM Friday...

Aloft, the sub-tropical ridge will progress eastward off the East
Coast on Sun, while the low continues enewd through the upper MS
Valley and into the Great Lakes. As the low moves ewd through the
Great Lakes and into southeast Canada Sun night/Mon, the attendant
trough will move eastward through the mid-Atlantic and Carolinas,
then shift offshore Mon eve/night. There will likely be a secondary
low tracking ewd across southern Canada Mon/Mon night, however the
medium-range guidance varies wrt how far south the attendant trough
will extend. Regardless, the trough will likely amplify swd along
but off the East Coast late Tue/Tue night. This could also impact
the strength/timing of the sub-tropical ridge as it approaches from
the west Tue/Tue night and through the area Wed/Wed night. The next
potential weather system will follow the ridge, but details remain
too uncertain for specifics at this time. At the surface, as the
high moves out over the Atlantic on Sun the ridge should gradually
weaken, holding on longest over the northwest Piedmont. As the next
cold front approaches from the west Sun night/Mon, a pre-frontal
trough will strengthen over the area, eroding what is left of the
ridge. The front should move sewd through the area late Mon/Mon
night, with Canadian high pressure ridging swd into the area for Tue
and Wed. There could be another fropa Thu/Thu night, but details
remain unclear.

Precipitation: The best chance for rain in the extended forecast
will be ahead of the cold front late Sun through Mon/Mon night.
Initially, the rain may be more stratiform in nature owing to
isentropic lift as warm moist air overruns the lingering ridge. This
could set up a period of CAD over the northwest Piedmont late
Sun/Sun night. If a CAD wedge does take hold, it should erode early
Mon as the pre-frontal trough strengthens. Precipitation should then
become more showery in nature, moving sewd through the area ahead of
the front. Coverage and amounts remain a bit uncertain at this time.

As for temperatures, if the CAD scenario plays out, temperatures may
need to be lowered in the NW Sun into Mon, but for now expect highs
Sun ranging from around 60 degrees NW to low 70s SE and lows Sun
night in the mid 50s to low 60s SE. Assuming the wedge erodes Mon,
highs should range from low/mid 70s north to mid/upper 70s south.
Temperatures should gradually decrease through mid-week, but
generally remain above normal.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
As of 120 PM Friday...

A slow-moving cold front, and lingering low-level moisture along and
ahead of it, will maintain a risk of MVFR ceilings for another hour
or three at FAY, RWI, and RDU. Following high pressure will favor
VFR conditions otherwise and elsewhere through the 18Z TAF period.
Nely flow behind the front will strengthen and become gusty for a
short time after sunrise on Sat, then weaken through the afternoon.

Outlook: "Return", sly flow, and associated moisture advection,
will contribute to the inland development/expansion of MVFR ceilings
late Sat night-early Sun. These ceilings are likely to lower to IFR
over the Piedmont, where rain and cold air damming will become likely,
later Sun-Sun night, then continue through early Mon. A chance of
showers will accompany a passing cold front late Mon-Mon night, with
following high pressure and VFR conditions through the middle of
next week.

&&

.CLIMATE...

Record High Minimum Temperatures:

November 8:
KGSO: 57/1975
KRDU: 64/1895
KFAY: 65/1946


.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...CBL
NEAR TERM...MWS/CBL
SHORT TERM...KC
LONG TERM...KC
AVIATION...MWS/Helock
CLIMATE...RAH