Area Forecast Discussion
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FXUS62 KILM 280758
Area Forecast Discussion
National Weather Service Wilmington NC
358 AM EDT Tue Mar 28 2017
The risk for showers and perhaps an isolated strong thunderstorm
will occur today ahead of a cold front which will move through
late tonight. Relatively cooler and drier high pressure will build
in from the north late Wednesday into Thursday. Showers and thunderstorms
are expected as warmer and more humid air returns Friday ahead
of a cold front which will move offshore early Saturday. Some of the
thunderstorms may be strong to severe Friday and Friday night. The
weekend should be dry as high pressure takes hold. Then early next
week, a southern stream system will again bring the risk for showers
.NEAR TERM /THROUGH TONIGHT/...
As of 300 AM Tuesday...A healthy warm and moist southerly
return flow along with clouds have kept temps up in the 60s most
places with dewpoint temps well into the 50s. This juicy air
mass ahead of a cold front will set the stage for an increasing
chc of shwrs/tstms through today. ML CAPE will reach over a 1000
J/kg as heating of the day occurs with increasing LLJ and
dewpoint temps up around 60. Expect increasing coverage through
the morning hours from west to east with increasing shear and
upper level support mainly over NC. The cloud cover may slow the
destabilization process but decent elevated CAPE early on will
be aided by heating of the day and upper level support to
produce added lift and potential for storms with gusty winds and
hail in isolated stronger storms. SPC has most of central and
eastern NC in a marginal risk for SVR weather diminishing as the
shortwave tracks off shore by late aftn. There may be some
lingering shwrs/tstms along the coast into early evening
depending on how fast the shortwave traverses the area.
Southerly winds will veer slowly to the SW and become gusty through
the day before shifting to the W by Tues evening as trough moves
through. Expect plenty of clouds through the day but some breaks or
brightening will allow temps to reach up toward 80 most places. The
increasing SW flow will fight against inland movement of sea breeze
and therefore the stable air behind sea breeze will remain pinned
closer to the coast. Overall expect increasing westerly flow aloft
and drier air to put an end to convection across the area by late
aftn with some lingering clouds into the evening. Pcp water values
up around 1.4 inches in the aftn will drop under an inch by midnight
as winds from the sfc up through the mid levels become westerly and
eventually northwest overnight. Clearing should take place overnight
although some residual low level moisture will remain into the
morning. Temperatures will drop off slowly as the cold front will
not actually make it through until the early morning hours on
Wed. Low temps should be in the mid 50s most places.
Although the official surf zone forecast season has not started yet,
local beaches will see an increase in rip current activity today.
This a result of a healthy SE ground swell affecting the local
waters and increasing the surf.
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As of 300 AM Tuesday...Cold front will be offshore Wed morning.
Strong high pressure centered across eastern Canada will begin
to ridge south across the Carolinas later Wed and Wed night. A
wedge will develop Wed night and persist into Thu before the
ridge begins to weaken and shift offshore Thu night. Dry weather
Wed into Thu as partial sunshine returns. A potent southern
stream system will approach from the W Thu night. Clouds will be
on the increase later Thu and especially Thu night. The system
has slowed down some, but will continue to advertise a slight
chance/small chance of showers and thunderstorms, mainly
overnight Thu with the lowest risk across the Cape Fear area and
the highest across the I-95 corridor and westward.
The cool air Will be slow to arrive and so highs on Wed should
still be well above normal, upper 70s to lower 80s with marine
influences keeping the coastal communities in the lower to mid
70s. Highs Thu will be in the upper 60s to lower 70s with
perhaps some mid 70s across portions of the Pee Dee. Lows will
be mainly in the 50s.
.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 300 AM Tuesday...Next in series of potent southern stream
systems will impact the eastern Carolinas Fri and Fri night with
a categorical risk for showers and thunderstorms developing.
The combination of significant upper level support and strong
and deep moisture return and lift provides at least the
opportunity for a more widespread and significant rainfall
event. There will be some risk for strong to severe
thunderstorms during this time. 0-6 km effective bulk shear
parameters are not particularly impressive. However, instability
does grow with mixed layer CAPE values on the order of 500 to
1000 J/kg as the warm front should move to our N. Mid-level
lapse rates are forecast to be rather modest. The potential is
there for an active day/night leading into the weekend, although
magnitude is certainly still a question mark.
In the wake of this system, dry weather and near to above
normal temps are expected for the weekend as mid-level ridging
builds across the area and surface high pressure builds from the
NW and N. Attention then will turn westward as next southern
stream system along the Gulf Coast Sun night lifts to the NE and
drags a warm front to the N. This will again bring deep
moisture into the Carolinas, and with that, showers and
thunderstorms early next week. Given timing differences between
long range models and a general slower trend as compared to 24
hours ago, will cap POPs in the chance category until we can
gain better resolution as to when the highest risk for showers
and thunderstorms will occur.
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
As of 06Z...VFR conditions will last until around daybreak as
upper disturbance reaches the area. Expect mainly MVFR SHRA but
an increasingly unstable air mass will produce isolated IFR
TSTMS mainly from 13Z thru 21Z with coastal terminals mainly
after 15Z. Winds will veer slowly through the day but may see a
slight backing along coastal terminals in the afternoon due to
sea breeze. Generally looking at SSW to SW winds 5 kt or less
overnight and picking back up to SW 10-15 kt during daylight
Tue. A cold front will lag behind the convection and will likely
push thru late Tue night into early Wed. Kept fog out of the
forecast as winds remain up overnight with plenty of clouds.
Extended outlook...MVFR and possibly IFR conditions possible from
fog Wed morning. MVFR/IFR conditions due to showers and
thunderstorms Fri/Fri night.
NEAR TERM /THROUGH TONIGHT/...
As of 300 AM Tuesday...SSW winds 10 kt or less will veer and
increase through today as gradient tightens a bit between high
pressure off shore and an approaching cold front. By this
evening winds will become more westerly remaining around 10 to
15 kt. Seas will increase but will remain in the 2 to 4 ft
range over SC waters and 3 to 5 ft in NC waters. The greater off
shore westerly wind component overnight will push most of the 5
fters beyond our local waters leaving 2 to 4 ft by morning.
Winds my spike up a bit as cold front crosses the waters Wed
A longer period SE swell will continue to reach our local waters
from a rather deep low pressure system well offshore from the SE
U.S. Coast forecast to move northeast, further away from the U.S.
mainland. Boaters navigating to and from area inlets on Tue could
encounter rough wave conditions especially during an outgoing tide
combined with the incoming 10+ second period swell.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As of 300 AM Tuesday...Cold front should be offshore at the
start of the period. Strong high pressure across eastern Canada
will build south and eventually wedge across the Carolinas Wed
night and Thu. The strong ridge should then move offshore Thu
night. N winds Wed morning will veer to NE. NE winds Wed night
and Thu will then veer to SE Thu night. Sustained wind speeds
will increase to 15 to 20 kt Wed night and remain in that range
through the end of the forecast period. Seas will build to 3 to
5 ft by Wed night and then remain in that range for much of Thu
before perhaps subsiding about a foot Thu night.
LONG TERM /FRIDAY THROUGH SUNDAY/...
As of 300 AM Tuesday...A Small Craft Advisory is likely for all
waters Fri and Fri night with conditions possibly lingering
Slow moving area of low pressure will be moving across the Ohio
Valley Fri. Its accompanying warm front will move across the
waters Fri. As low pressure moves offshore of the Mid-Atlantic
states late Fri night and Sat morning, it will strengthen and
drag a cold front across the waters. High pressure will slowly
build across the area from the N and NW Sat night and Sun.
SE winds Fri morning will become S and then SW Fri night. The
wind direction will become westerly early Sat morning and then
NW by Sat afternoon. N winds Sat night will become NE overnight
Sat with NE winds persisting into Sun before veering to easterly
during the afternoon.
The strongest winds are expected Fri and Fri night, up to 20 to
25 kt. Seas late Fri and Fri night will build to 4 to 7 ft and
around 8 ft at frying Pan Shoals. Seas during Sat will only slowly
subside as backswell from departing storm system impacts the
waters. Seas should drop below advisory levels by late Sat and
to 2 to 4 ft on Sun.