Area Forecast Discussion
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FXUS62 KILM 211530
Area Forecast Discussion
National Weather Service Wilmington NC
1130 AM EDT THU JUL 21 2016
The cold front that passed to our south will continue to dissipate
as high pressure build into the area and a piedmont trough
develops to our west Friday through the weekend. Temperatures
will surge back above normal for the weekend, with the possibility
of showers and thunderstorms increasing early next week.
.NEAR TERM /THROUGH TONIGHT/...
As of 1130 AM Thursday...Morning soundings are showing drier air
at GSO and MHX and an inversion around 550 mb at MHX today.
Instabilities are down by half in the northeast 2/3 of the
forecast area and this reflects where the best and less favorable
chances of convection are this afternoon. A chance of
thunderstorms are possible mainly from Andrews to Dillon as the
best moisture and instability is this area. Also, the sea-breeze
may see an isolated thunderstorm with the best chances from
High temperatures are expected to be in the lower 90s inland and
the upper 80s at the beaches.
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 345 AM Thursday...NO POPS being fcst in this 2 day period.
Increasing heat combined with the humidity, will result in heat
indices shy of Advisory criteria on Friday but should break
through thresholds and become widespread on Saturday.
High pressure aloft will bake the Central U.S. this period. One
of its ridge axis`s will extend just north of the area during this
weekend. With dry and warming air in the mid levels, along with
primarily subsidence aloft, the ILM CWA will see a decent
convective lid across the region thruout this period. Clouds will
be limited to diurnally driven cu/sc this period...enhanced by the
sea breeze. In all, no POPs. Widespread 90s for both days, with
sfc dewpoints slowly increasing and becoming widespread 70s by
Saturday. Mixing from aloft may bring down some 60 degree
dewpoints inland on Fri but likely not the case for Sat. Will
indicate Heat Advisory conditions for Sat in the HWO.
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 3 AM Thursday...500mb ridge right overhead Sunday and Monday
and this should keep hot temperatures and little to no precipitation
chances in the forecast. Guidance is showing some areas hotter
Sunday vs Monday while other guidance reverses this trend. In the
end unless the sea breeze dictates otherwise along the coast both
days appear quite similar and both likely candidates for Heat
Advisories. The ridge may be more stalwart than previously though
especially according to the 00Z GFS which now shows little to no
retrogression and thus a similar hot and humid forecast. We may now
have to wait until Wednesday for just enough retrogression of the
ridge from some vorticity centers to stream across the area in the
resulting NW flow. This could temper the heat and also lead to
better chances of thunderstorm, maybe strong to severe ones.
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
As of 12Z...Patchy areas of MVFR/IFR possible due to fog this
morning and Friday morning. Otherwise expect VFR with an isolated
shower or thunderstorm possible this afternoon.
Latest observations depict patchy fog this morning creating areas
of MVFR. Expect conditions to improve to VFR area-wide within the
next hour or two, continuing through the rest of today with an
isolated shower or thunderstorm possible. Light and variable winds
this morning will become east-northeasterly and then east-
southeasterly by this afternoon, with sustained winds around 10
kts or less. Overnight, winds become nearly calm with the potential
for MVFR due to fog towards morning.
EXTENDED OUTLOOK...Brief periods of MVFR/IFR from isolated
afternoon convection through Saturday. Otherwise expect VFR.
NEAR TERM /THROUGH TONIGHT/...
As of 1130 AM Thursday...The stationary front continue to
dissipate and high pressure will build in over the waters
overnight. Winds are light from the north to northwest with seas
of 3 feet. The 3 ft swells are from a east-southeast to southeast
with a periods of 8 and 11 seconds.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 400 AM Thursday...High pressure will build across the
waters from the High`s center offshore from the SE States during
this period. Inland, the Piedmont trof will become a mainstay
during this period. The 2 features will combine and affect the
area waters with winds becoming SW thruout on Fri and continuing
thru Saturday. The mesoscale sea breeze will result in S to SSW
winds nearshore each aftn and evening and provide the increased
wind chop. The sfc pg will be somewhat relaxed Fri with wind
speeds generally around 10 kt. The sfc pg tightens Sat thru Sat
night with wind speeds at 10 to 15 kt with gusts up to 20 kt
possible Sat Aftn thru Sat Night. Significant seas will run 2 to
occasionally 3 ft on Fri with the 1 to 2 foot ese-se ground swell
dominating. For Sat, increasing SW winds will build the local wind
chop and when added to the 1 to 2 foot ground swell, significant
seas will run 2 to 4 ft. No convection being forecast this period.
LONG TERM /SUNDAY THROUGH MONDAY/...
As of 3 AM Thursday...A very unsettled set of changing
conditions. This is not only fairly typical during the heart of
summer but it becomes even moreso during a heatwave. Winds will be
10-15kt and southwesterly with a piedmont trough in place while
the Bermuda high is displaced eastward of its normal position.
Seas will average 2 to 3 and occasionally 4 ft.