Area Forecast Discussion
Issued by NWS Wilmington, NC-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS62 KILM 301135
Area Forecast Discussion
National Weather Service Wilmington NC
735 AM EDT Thu Mar 30 2017
A wedge of high pressure will weaken and move offshore today.
Showers and thunderstorms are expected to overspread the area
late this afternoon and this evening and then persist overnight
and into Friday ahead of a warm front. Some of the thunderstorms
could be strong to severe late tonight into Friday. A cold
front will follow later Friday or Friday night. The weekend
should be dry as high pressure takes hold. Low pressure early
next week will bring more showers and thunderstorms. Brief high
pressure may be followed by another round of showers and
thunderstorms next Thursday and Thursday night.
.NEAR TERM /THROUGH TONIGHT/...
As of 300 AM Thursday...The wedge of high pressure remains across the
area this morning under weak ridging aloft. A slow moving storm
system currently in the Mississippi Valley will move east
today. This in turn will weaken the surface high pressure along
with the mid level ridge. High resolution models are very
consistent on some convection developing just to the west of our
CWA this afternoon on what will be the convergence area of the
retreating ridge and stronger southerly flow with the main storm
system. There is about 400 J/KG of CAPE so a rumble of thunder
cannot be ruled out. Most of the area should remain dry however.
For later tonight, more convergence showers should develop and a
streamer off the Atlantic could advect across. The "main" line of
convection will move across just after 1200 UTC Friday. No real
storyline regarding temperatures other than readings have warmed
slightly for today. I also jogged up morning lows for Friday as a
breezy, showery scenario with early lows takes place.
Finally regarding severe potential, which SPC has placed most of our
area in a marginal risk in the latest day one outlook, as per their
discussion, difficult to pinpoint the risk but overall feel with the
stronger wind fields arriving just after 12z Friday, that will be
the window of greatest threat for our area.
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 300 AM Thursday...A broad area of low pressure will be
moving across the Ohio Valley and central Appalachians and Mid-
Atlantic states Fri with a complex frontal system trailing
south. A warm front and its associated isentropic lift will be
moving across the Forecast Area Fri with widespread showers and
thunderstorms expected. We may become dry slotted Fri ahead of a
cold front which will move across the area later Fri or Fri
night. High pressure will then build from the N Sat and Sat
night as a mid- level ridge builds across the Southeast.
There continues to be a risk for strong to severe thunderstorms
Fri. The timing of this system should help to mitigate the risk.
However, 0-6 km effective bulk shear values will be in the 40 to
50 kt range and instability does increase with mixed layer CAPE
values peaking in the 500 to 1000 J/kg. Low level jetting
increases to 40 to 45 kt. Thick clouds and rainfall should help
to mitigate the instability, especially early on, but a period
of dry slotting may allow clouds to thin during Fri which could
support greater instability and increase the severe risk.
Highs on Fri will be in the mid and upper 70s with lower 70s at
the south facing beaches. Any significant breaks in the clouds
may allow temps to surge into the lower 80s Fri afternoon. Lows
late Fri night will drop into the mid and upper 50s with around
60 at the beaches. Highs on Sat will range from the mid to upper
70s with a few 80 degree readings possible across inland
locations. It will be a little cooler Sat night, mainly lower
to mid 50s.
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 300 AM Thursday...Strong low pressure will be pulling NE across
the Canadian Maritimes Sun as high pressure becomes well
established across the Carolinas. The center of the high will
move E of the area Sun night as next in series of potent
southern stream systems across the Ark-La-Tex Mon moves east
across the southern Appalachians and Carolinas Tue, then
accelerates to the NE and intensifies offshore of the Mid-
Atlantic states late Tue and Tue night. Yet another area of low
pressure and its associated frontal system will approach the
area Wed night with its greatest impacts across the eastern
Carolinas expected Thu/Thu night.
The system early in the week has the potential to bring strong
to severe thunderstorms. This very progressive pattern is
expected to bring rainfall, some of which will be significant.
After a dry Sun and Sun night, Pops will be increasing Mon with
the most widespread coverage of showers and thunderstorms likely
Mon night with a decreasing trend on Tue. A return to dry
weather Tue night through Wed night may very well be followed by
more showers and thunderstorms Thu/Thu night.
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --As of 12Z...Some stratus around this morning near KLBT and KILM
primarily. Will add scattered stratus below 1 kft at KILM and
tempo IFR ceiling at KLBT through about 14z.
Expect scattered to broken cumulus and stratocumulus to develop
as heating gets underway, at times ceilings will drop to MVFR.
For later this afternoon and tonight, expect ceilings to lower
with showers and thunderstorms increasing from SW to NE with
the coastal terminals the last to experience widespread shower
and thunderstorm activity very late in the valid TAF period. Expect
ceilings and visibilities to drop to MVFR and IFR in rain.
Extended outlook...MVFR to IFR conditions likely persisting
into at least the first part of Fri. More showers and
thunderstorms developing Mon and through Mon night will have the
potential to produce flight restrictions.
-- End Changed Discussion --
-- Changed Discussion --NEAR TERM /THROUGH TONIGHT/...
As of 700 AM Thursday...A Small Craft Advisory has been issued
for all waters late tonight through Fri and into Fri night.
Winds will continue to slowly relax through the morning hours
allowing the seas to follow into a 2-4 foot range as the wedge
of high pressure responsible for the conditions weakens and
begins to retreat. Winds will increase once again late tonight
from the southeast in a range of 15-20 knots and seas will
follow well into small craft criteria by Friday morning.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 300 AM Thursday...Small Craft Advisory conditions will be
ongoing at the start of the period and are expected to wind down
A broad area of low pressure will be moving across the Ohio
Valley and central Appalachians and Mid-Atlantic states Fri
with a complex frontal system trailing south. Widespread
showers and thunderstorms, some of which will be strong to
possibly severe, will be ongoing at the start of the period as a
warm front moves across the waters.
The wind direction will be S, veering to SW Fri and then W and
finally NW toward Sat morning with passage of the cold front.
Winds will generally be NW Sat although winds will have a
tendency to back ahead of reinforcing cold and dry push. Winds
will then veer back to NW Sat eve and to NE overnight Sat. Wind
speeds will be 20 to 25 kt Fri, diminishing to around 15 kt
overnight Fri into Sat before diminishing further later Sat and
Sat night as high pressure becomes firmly established.
Seas will be 5 to 7 ft Fri, subsiding slowly to 3 to 5 ft Fri
night due to backswell and then to 2 or 3 ft late Sat and Sat
LONG TERM /SUNDAY THROUGH TUESDAY/...
As of 300 AM Thursday...Small Craft Advisory conditions
likely developing Mon and continuing into Tue. Gusts to gale
force can not be ruled out.
Strong low pressure will be pulling NE across the Canadian
Maritimes Sun as high pressure becomes well established across
the Carolina waters. The center of the high will move E of the
waters Sun night as next in series of potent southern stream
systems across the Ark-La-Tex Mon moves east across the southern
Appalachians and Carolinas Tue, then accelerates to the NE and
intensifies offshore of the Mid-Atlantic states late Tue and
The worst of the marine conditions with the system early next
week will come Mon afternoon, peaking Mon night and Tue morning.
Numerous to widespread showers and thunderstorms will be impacting
the waters during this time. Sustained wind speeds will be up
to 25 to 30 kt with higher gusts. The direction will be SSE to S
on Mon, veering to SW Mon night and eventually to the W later
Tue. Seas will be building Mon and peaking in the 6 to 9 ft
range Mon night and early on Tue.
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-- Changed Discussion --SC...None.
MARINE...Small Craft Advisory from 11 PM this evening to 2 AM EDT
Saturday for AMZ250-252-254-256.
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