Area Forecast Discussion
Issued by NWS Wilmington, NC-- Remove Highlighting --
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FXUS62 KILM 220235
Area Forecast Discussion
National Weather Service Wilmington NC
1035 PM EDT THU JUL 21 2016
The cold front that passed to our south will continue to dissipate
as high pressure builds into the area and a piedmont trough
develops to our west Friday. Temperatures will surge back above
normal for the weekend, with the possibility of showers and
thunderstorms increasing early next week.
.NEAR TERM /THROUGH FRIDAY/...
-- Changed Discussion --As of 1030 PM Thursday...No additional changes are necessary to
the forecast. The last of the diurnal convection is dead and
inland winds are diminishing toward calm. Visibilities may begin
to drcrease inland toward daybreak where moisture content of the
boundary layer is highest, but fog isn`t anticipated to be an
issue. Discussion from 730 pm follows...
The last puffs of diurnal convection are ongoing along the
seabreeze front northwest of Georgetown. Look for this activity to
die down over the next hour as the boundary layer begins to
stabilize. With no upper level disturbances upstream there is
little reason to expect any additional showers or storms
overnight. Forecast lows have been tweaked down just slightly east
of I-95 due to very light winds anticipated in a reasonably dry
airmass for this time of year. Discussion from 300 PM follows...
Convection as was anticipated is struggling with drier air and
the the weak inversion aloft at 550 mb. A few convective towers
tried to develop along the sea breeze earlier but struggled
Current visible satellite is showing cumulus development in the
counties of Darlington, Florence, Williamsburg, Georgetown,
Marlboro, and Marion. But as of 3 PM nothing is developing over the
southwest area but areas farther to the south and west where
conditions are better convection is firing. Thus will keep a slight
chance of thunderstorms for the area mentioned above.
Overnight, skies will be mostly clear and lows will fall into the
lower 70s inland and the middle 70s at the coast.
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.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
As of 300 PM Thursday...High pressure will continue to build over
the region. Temperatures will slowly increase and low-level moisture
increases also with the high pressure dominating the region. The heat
indices will increase through the period with values at or above 105
degrees away from the coast on Saturday and Sunday when heat advisories
are expected to be posted for portions of our area.
On Saturday the Piedmont trough develops and there will be an slight
increase in chances for thunderstorms. Focus for the convection
will be along the sea-breeze front and farther to the west with
the differential heating of the Carolina Sandhills.
Highs on Friday will range from the upper 80s at the beaches to
94 inland. On Saturday, highs will range from the upper 80s on the
beaches to 96 inland. Low temperatures will be in the middle 70s
.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 300 PM Thursday...Upper level ridge holds on over the
Carolinas through early next week before breaking down a bit as a
northern stream system moves east and upper level low tracks west
from the Atlantic south of the ridge. The main ridge extending in
from the mid west will retreat westward and weaken over the
southeast but the atlantic ridge will build westward by Tues into
mid week next week. The northern stream shortwave will drive a
cold front south and east as it tracks across the Great Lakes into
New England Monday into Tuesday. This front may reach down into
North Carolina come next Wed/Thurs time frame as it gets stretched
out from west to east as ridge builds in from east and flattens
Overall, Bermuda High and Piedmont trough will be the main
players in forecast at the sfc, much of the week. The s-sw flow
around the Bermuda High will keep a more warm and humid, unstable
air mass in place with more in the way of localized convection
along sea breeze and trough inland, expected most of the week
with not too much in the way of upper level support as ridge holds
on. GFS/ECMWF both show an upper level low breaking off from
trough to the east over the atlantic and tracking westward...but
it should remain to the south of the upper ridge Mon into Tues and
should just act to displace one ridge as another builds in.
The influence of upper ridge will help to keep above normal
temperatures especially Sun/Mon as ridge extends almost directly
overhead with limited convective activity. By mid week, the
influence of the front to the north and retrogression of ridge
extending in from the Midwest should increase chc of convection
and clouds across the area which may shave a few degrees off the
max temps. Right now, it looks like heat advisory thresholds will
continue to be reached Sun through Mon and possibly into Tues
over most of the area.
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
As of 00Z...Potential for periods of MVFR/IFR/LIFR associated with
fog early Friday morning. Otherwise VFR through thIS TAF valid
There is high confidence of VFR at the terminals through midnight.
Afterwards there is an increasing chance of MVFR vsbys, mainly
inland terminals. In the pre-dawn hours patchy dense fog will develop
near the inland terminals. Since the fog will be patchy there is low
confidence of occurrence.
Winds will decrease to light and variable this evening and remain
so through the overnight hours. around mid-morning winds will become
southerly 5-10 kts, highest at the coastal terminals.
EXTENDED OUTLOOK...Brief periods of MVFR/IFR from isolated afternoon
convection Saturday through Tuesday. Otherwise expect VFR.
-- Changed Discussion --NEAR TERM /THROUGH TONIGHT/...
As of 1030 PM Thursday...No significant changes are needed to the
forecast this evening. Light southerly winds will veer more
offshore very late tonight with a landbreeze circulation.
Discussion from 300 PM follows...
The front has dissipated and winds are now northeast off the
coast and southeast to south as the sea- breeze circulation is now
well established near the coast. Wind speeds are still at 5 to 10
knots and seas are running around 3 feet. The buoys are still
detecting the 2.5 to 3 ft ground swell with a period of 9 seconds
from the southeast along the coast. Do not anticipate a change
overnight in the sea heights.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 300 PM Thursday...As the high pressure becomes established
the light and variable winds will shift to the southwest by Saturday.
Winds speeds will increase from the 5 to 10 knots to around 15 knots
by Saturday afternoon. Seas will be 2 to 3 feet on Thursday and increase
to 2 to 4 feet by Saturday in response to the increased southwest winds.
LONG TERM /SUNDAY THROUGH MONDAY/...
As of 300 PM Thursday...South to southwest winds will continue
around the Bermuda High. Winds will generally stay in the 10 to
15 kt range with a slight spike in late aftn into early eve,
enhanced by the sea breeze and piedmont trough. Seas will remain 3
ft or less with a continued 8 to 9 sec E-SE swell mixing in.
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