Area Forecast Discussion
Issued by NWS Wilmington, NC-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS62 KILM 202316
Area Forecast Discussion
National Weather Service Wilmington NC
616 PM EST Fri Jan 20 2017
A warm front just north of the area will drift slowly back
south as low pressure lifts off to the northeast tonight.
Another area of low pressure will move through Saturday into
Saturday night. A more complex and potent storm system will
affect the Carolinas on Sunday with potential for severe
weather. Total rainfall amounts should amount to one to three
inches. This storm system will slowly depart through Monday
leaving high pressure for Tuesday and Wednesday. A cold front
will move across the area on Thursday.
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
-- Changed Discussion --As of 615 PM Friday...Temperatures remain elevated in the lower
to mid 60s this evening as a light southerly flow continues
behind a departing warm front. Still anticipating a mainly dry
overnight period, with rain changes marginally increasing around
daybreak. Previous discussion follows:
Warm front is located north of forecast area with all obs
showing southerly winds with temps just into the 70s and
dewpoint temps near 60. Pcp remains fairly inexistent with only
a spotty light shower possible through this evening. Breaks in
the clouds have led to periods of sunshine and soundings
continue to show plenty of dry air in the mid to upper levels
working down through the column through this evening as winds
veer to the west. Therefore have kept previous forecast leaving
pops out of forecast through most of tonight.
The warm front just north of area will drift south as low
pressure pulls away tonight. Winds will become very light and
variable at the surface while low level flow will veer from SW
to W before backing around to the SW again by morning. This will
allow moisture to increase through the column once again and
have included some potential for pcp toward daybreak. Not
expecting measurable rainfall tonight, although some spotty
drizzle may occur tonight, as well as, low stratus and fog
development and have included areas of fog in the grids at this
time. Widespread fog may turn dense overnight as dewpoints
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.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
As of 300 PM Friday...Shortwave riding up from the southwest
on Saturday will increase lift and potential for pcp through
Sat. Models show this wave of low pressure exiting the coast
Sat night while a potent shortwave digs down through the gulf
coast. The associated surface low will deepen as it reaches the
western Carolinas late Sun aftn. Expect a break in convection
through Sat eve but expect an uptick in pcp toward Sun morning
and convection to become strong to possibly severe on Sunday
aftn into Sun evening. Pcp water values will reach up to 1.5
inches Sat aftn, diminishing slightly into Sat night before
increasing again through Sunday as LLJ reaches up to 45 to 50
kts. The best bulk shear values come Sun aftn into early
evening up over 80 kts. SPC has most of area in slight risk for
severe weather on Sunday. QPF should be on the high side this
weekend with up to 1 to 3 inches possible with some localized
flooding possible as well as contributing toward possible river
flooding into early next week.
.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 300 PM Friday...Anomalously deep stacked low pressure will
move through the central Carolinas on Friday. Most of the
precip/convection with this system will occur before the long term,
but as spokes of vorticity move overhead Monday, a few showers will
be possible through the day. The cold front tailing this system will
drag offshore Monday night, but by then the atmosphere will be too
dry for any further showers, and the only noticeable difference will
be somewhat cooler air Monday night and Tuesday, when temps will
drop to just slightly above seasonable norms.
Any cooldown is short lived, as the quick mid-level pattern allows
ridging to blossom quickly once again across the Southeast. The
Wed/Thu timeframe appear very warm, with 70s returning to the area,
ahead of a strong cold front progged to cross the Carolinas early on
Thursday. This cold front may signal the beginning of a regime
change, as a large trough dives into the eastern CONUS with
seasonable or even below seasonable temperatures possible at the
end of the week.
.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
As of 1730Z...VFR conditions will deteriorate after midnight
tonight as elevated dewpoints and low-level moisture transport
work into the area. IFR ceilings expected AFT 6Z, with VSBYS of
1/2-2SM overnight through end of the taf cycle. IFR conditions
may not be widespread but will prevail over a large portion of
SE NC and NE SC from late tonight through Saturday morning with
OCNL -RA AFT 15Z.
Extended outlook...IFR/LIFR likely continuing Saturday morning.
Tempo MVFR or lower ceilings and visibility expected in showers and
thunderstorms Saturday afternoon through Sunday night. Thunderstorms
will have the potential for strong to severe wind gusts Sunday
afternoon and night.
-- Changed Discussion --NEAR TERM /THROUGH TONIGHT/...
As of 615 PM Friday...Latest obs show seas in the 2 to 3 ft
range with SW winds of 10 to 15 kts. This fits in well with the
going forecast. No changes anticipated to the overnight period,
previous discussion follows:
A warm front north of waters leaves all waters in S-SW winds
through tonight. Seas will remain 2 to 3 ft this afternoon in S
to SW winds 10 to 15 kts.
As the low moves north tonight the front should drift south
lightly producing more variable winds mainly over northern
waters, but remaining very light. Seas will remain 2 to 3 ft.
Winds in the northern waters may be E-NE overnight but will come
back around to the E-SE through Sat morning while winds above
the surface will shift back to the SW by morning. There is some
concern for sea fog development and reduced visibility late
tonight and have included through a good portion of the weekend.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 300 PM Friday...A shortwave will track up from the
southwest on Saturday. This will aid in enhanced lift and
potential for more widespread shwrs and iso thunderstorms over
the waters as another wave of low pressure moves through. Most
of the waters will experience warm moist air streaming over the
cooler waters. This could produce sea fog through much of the
weekend. A more favored SW trajectory through Saturday will lead
to better chances of fog. By Sunday, a more potent storm system
will move up from the southwest with increased potential for
strong convection. Winds will become more on shore while
increasing up to 20 to 25 kts. This persistent and increased
southerly push will drive seas up from 2 to 4 ft Sat up to SCA
thresholds by late aftn or early eve on Sun and possibly
reaching up to 7 to 9 ft Sun night.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
As of 300 PM Friday...Strong low pressure moving through the
central Carolinas will drag a cold front across the waters late
Monday into Tuesday. Gusty SW winds will reach 20-25 kts ahead
of this front driving seas to 5-8 ft, before a wind shift occurs
by Tuesday morning to the NW followed by a slow decrease in
speed. An SCA will likely be needed all of Monday and perhaps
into Tuesday morning, before conditions improve below headline
thresholds. NW winds Tuesday will fall slowly from around 20 kts
early, to 10 kts late, and then will back again to the SW
Wednesday with an increase in speed once again. Wave heights
will fall to as low as 2-3 ft late Tuesday thanks to the slowing
speeds and offshore wind component, but will ramp back up again
to 3-5 ft late in the period.
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