Scientific Forecaster Discussion
fxus62 kilm 211039
Area forecast discussion
National Weather Service Wilmington NC
635 am EDT Sat Sep 21 2019
a gradual warming trend is expected in the days ahead with
skies remaining fair to partly cloudy, and very little chance
of rain in the upcoming period.
Near term /through Sunday/...
surface streamlines this morning reveal a high pressure circulation
centered over the inland northeast corner of SC, centered between
Hyman and Hannah. This feature is holding in check a coastal land-
breeze boundary adjacent to it along the NE SC coast, earlier
producing a zone of clouds from Georgetown to Holden Beach. Onshore
wind today will allow moisture remnants to transition to afternoon
cumulus inland, but mostly sunny will characterize much of the day
for many if not most locations. 1-4 degrees warmer today than
yesterday, more notable inland, lesser change by the coastal zones.
Primary hazard today resides in the surfzone of area beaches, as
lingering swell will maintain a few strong rip currents, on the
official last weekend of Summer, before equinox 9/23/350am EDT, and
with moderate to large crowds expected, rescues are anticipated.
Into Sunday, although onshore, moist maritime flow continues to
spread inland, it remains shallow, with desert-like air above 6000
feet. As such we have pop values too low for inclusion through the
period, outside of an isolate marine shower well out. Daytime
temperatures Sunday are expected to be similar to today. If there is
any difference, we might see a bit more cumulus Sunday, and patches
of fog into daybreak of slightly increased coverage.
Short term /Sunday night through Monday night/...
high pressure will shift farther off the NC coast Sun night with
a light return flow, becoming more southerly through Mon as a
dry cold front approaches from the northwest. The ridge gets
suppressed slightly farther south on Monday while mid to upper
trough swings across the Great Lakes, pushing this cold front
south and east. It will push this front through the Carolinas,
but the ridge aloft will begin to build back up from the south
helping to suppress any pcp, but do expect some clouds. The
moist return flow will push dewpoints up a bit with overnight
lows in the low to mid 60s most places. Highs on Mon will be in
the mid 80s to near 90.
Long term /Tuesday through Friday/...
quiet wx expected next week as a dry cold front moves farther
off shore Tuesday, followed by high pressure for the remainder
of the week. Minor perturbations over the top of the upper ridge
may produce a spotty shower, but for now will keep pcp out of
forecast Wed into thurs. High pressure will dominate Fri into
the weekend as deep ridge of high pressure builds over the
southeast. Conditions will be more Summer-like with dewpoints in
the mid to upper 60s and day time highs in the mid 80s to around
Aviation /12z Saturday through Wednesday/...
VFR. The only low-end exception, 2-4sm br early portion of taf
period from 09-12z. Light/calm wind becoming southeast this afternoon
5-11 knots. The wind direction will bring Atlantic moisture
inland, resulting a few fair-weather afternoon cumulus of
limited vertical extent.
Extended outlook...VFR, except localized to patchy fog early
mornings through early next week.
favorable seas for mariners, very little steepness or wind-
sea, dominated by swell from the east between 11-13 seconds, as
Humberto's back-thrown wave-train continues a fade trend. By
Sunday however, we will receive additional wave-trains, Jerry
fore-runners and a more more local southeast wave from the southeast at 7
seconds. Still, all this will 'not' raise any advisories as
wave-heights remain low.
The longer period waves although not large, may cause standing
wave turbulence in entrances during outgoing tides. No thunderstorms
this period, isolated marine showers in and near the Gulf
A weak and dry front will approach from the northwest Mon night into
tues while Jerry passes by well east of the waters. This should
kick S-SW winds up a bit late Mon and should swing winds around
to a more off shore direction on tues. High pressure will shift just
east of the local waters and dominate Wed through the remainder
of the week. Seas in the 2 to 3 ft range Sun night will increase
up to 3 to 4 ft Mon night into tues. Overall expect seas in the
2 to 4 ft range with longer period southeast swells mixing in.
SC...high rip current risk through this evening for scz054-056.
NC...high rip current risk through this evening for ncz106-108.