Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 101408
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
908 AM EST Mon Dec 10 2018

.SYNOPSIS...
Clouds and occasional rain will continue today into tonight as
a final area of low pressure develops across the eastern
Carolinas. A little snow could mix in late tonight into Tuesday
morning as precipitation ends, but no accumulation is expected.
Temperatures will remain below normal Tuesday through Thursday
as high pressure moves across the Carolinas. Another low
pressure system should bring more rain Friday and Saturday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 915 AM Monday...No changes to the forecast this morning
and no surprises. Dreary day with light rain and drizzle from
time to time. Bigger challenge arrives tonight regarding if or
when any light wintry precipitation occurs. Latest high
resolution guidance really hasn`t changed much with regards to
this as well. Previous discussion follows:



A cold and dreary Monday expected today as highs
remain stuck in the upper 30s inland to lower 40s along the coast.
Temperatures this chilly are approaching 20 degrees below
climatology in many places. This is a result of low pressure off the
coast associated with yesterday`s wind/rain event. Moderate
northerly flow on the west side of this system continues to drag
cold air into the Carolinas. Atop the surface layer is easterly low
level warm advection/isentropic upglide to keep the clouds socked in
and also leading to a gradual ramping up of some light rain, with
northern zones being favored over southern. Surface and low level
trough then sink southward away from the region later tonight and
the sense of thermal advection switches to cold. As the moisture
wanes towards daybreak the precipitation will be capable of mixing
with snow flurries as it shuts off. The lack of any warm layer will
preclude freezing precipitation while the diminishing ascent and
available moisture precludes any chance of accumulation.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 300 AM Monday...The last strong shortwave aloft should be
exiting the coast around sunrise Tuesday. The back edge of the
deeper moisture up should push offshore between 8-10 AM, taking
any lingering light precipitation out to sea. As low-level cold
advection continues there is some concern about what form
lingering precip might take. The 00Z NAM has a fairly cold low-
level profile that would support snow, or at least a snow/rain
mix Tuesday morning. The 00Z ECMWF and GFS show a continuing
warm nose centered on 925 mb (~2500 feet AGL) that would melt
falling hydrometeors to rain. In either case surface air temps
could be very close to freezing in Burgaw, Wilmington, and
Southport. Fortunately any precip falling Tuesday morning
should be very light, perhaps just trace amounts, with dry
weather developing even at the coast by late morning.

Skies should be clear inland by 10 AM, with clear skies
developing for the Grand Strand and Cape Fear area by early
afternoon at the latest. Highs Tuesday should only reach the
upper 40s to around 50, a good 10 degrees below normal.

Surface high pressure centered along the Gulf Coast will build
eastward Tuesday night and will reach the Carolinas on Wednesday.
Large diurnal ranges are expected Tuesday night into Wednesday
with lighter winds and clear skies. Lows should fall into the
20s almost down to the beaches Tuesday night, and highs Wednesday
to rise to 51-55 degrees. The high will nudge offshore Wednesday
night, allowing a return flow to begin, with lows 30-35 except
warmer near the beaches.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 325 PM Sunday...High pressure will shift across the
region on Wednesday and a wedging pattern develops on the lee
side of the Appalachian mountains and a coastal trough/front
develops Wednesday evening into Thursday. A strong mid-level
trough drops down over the Red River area on Thursday and will
work its way across the the Mid- Atlantic coast by late weekend.
At the surface, a strong low pressure area develops over the
Ark-La-Tex Thursday and swings eastward up the Appalachians
mountain chain. This will put our area in the warm sector on
Friday and a good chance of rain with thunderstorms on Friday
into Friday night. The weekend will dry out.

A warming trend is expected ahead to the surface front on Friday
with temperatures dropping back a bit on the weekend. Maximum
temperatures in the lower 50s on Wednesday will warming into the
lower to middle 60s on Friday before settling back into the 50s over
the weekend. The low temperatures will be in the lower to middle 30s
Wednesday night and they will warm into the lower 40s to lower 50s
for the remainder of the forecast.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
As of 12Z...High confidence in IFR conditions through the majority
of the TAF period. Light rain at the coastal terminals along with
some light drizzle at the inland terminals will persist
intermittently through this evening keeping low-levels saturated.
Majority of the rain will fall this morning although we could see a
break in shower activity between 15Z-20Z with increasing shower
chances as the bulk of the moisture moves southward this afternoon
and evening. A light mixed precip shower is possible (provided
enough moisture still exists) at FLO as the precip begins to taper
off around 02Z-05Z and cold northerly air deteriorates the lingering
warm nose. High confidence in conditions improving to VFR inland and
MVFR at the coast by the end of the forecast period.

Extended Outlook...MVFR Mon evening into Tuesday. VFR through Thu
before a return to MVFR Fri potentially due to another coastal
low.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
As of 300 AM Monday...Advisory flags to be flying for the
duration as well as beyond. Slow moving low pressure off the the
northeast slow to exit due to strengthening energy aloft
through midday today. Chilly high pressure sprawled across the
eastern U.S. paired with the offshore low will keep the gradient
moderately strong locally supporting both advisory-worthy wind
and seas, the former continuing out of the north.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 300 AM Monday...The final area of low pressure in our
strong weekend storm system will exit the coast early Tuesday,
allowing high pressure along the Gulf Coast to build eastward
across the Carolinas on Wednesday. Breezy offshore winds and
considerable large backswell from the offshore low on Tuesday
will necessitate an extension of the Small Craft Advisory. By
Wednesday wind speeds should die down below 10 knots with seas
falling to only 1-3 feet.

LONG TERM /THURSDAY THROUGH FRIDAY/...
As of 325 PM Sunday...High pressure will move over the waters
and will transform into the classic coastal trough and wedging
high pressure on the lee side of the Appalachians pattern. Winds
will begin this period from the northwest at 10 to 15 knots and
will become light and variable as the coastal trough develops.
Winds increase from the southeast at 15 to 20 knots on Friday
and seas will increase with a small craft advisory expected
again of Friday.

&&

.CLIMATE...
As of 300 AM Monday...Wilmington`s rainfall Sunday amounted to
1.22 inches at the airport, pushing the annual total to a new
all-time record of 97.67 inches. Additional rainfall today &
tonight could add another tenth of an inch to this total. This
would leave us roughly 2.2 inches short of 100 inches for the
year. Looking ahead toward the next storm system late in the
week, a tight rainfall gradient is expected along the coast as
maritime instability could play a role in precipitation
distribution. Latest WPC progs indicate around 2 inches possible
Thursday through Friday night.

Odds are looking very good we`ll break the 100-inch barrier in
Wilmington. See https:/weather.gov/ilm/RaceTo100 for details.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...Coastal Flood Advisory until 1 PM EST this afternoon for
     NCZ107.
MARINE...Small Craft Advisory until noon EST Tuesday for AMZ254-256.
     Small Craft Advisory until 9 PM EST Tuesday for AMZ250-252.

&&

$$
SYNOPSIS...TRA
NEAR TERM...MBB/SHK
SHORT TERM...TRA
LONG TERM...RH
AVIATION...21
MARINE...
CLIMATE...



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