Area Forecast Discussion
Issued by NWS Charleston, SC
FXUS62 KCHS 251933
Area Forecast Discussion
National Weather Service Charleston SC
333 PM EDT MON JUL 25 2016
Atlantic high pressure will prevail through much of the week while
a weak trough persists inland.
.NEAR TERM /THROUGH TONIGHT/...
Convection has struggled today given increasing heights aloft and
extensive mid-level dry air noted on water vapor imagery. While a
brief, transient shower could still develop along/head of the sea
breeze through late afternoon, expect dry conditions to prevail
through the evening and overnight hours. Warm and humid
conditions will persist with lows ranging from the mid 70s inland
to the lower 80s at the beaches, Downtown Charleston and around
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
A persistent weather pattern is in place as strong Atlantic
mid/upper-level ridging extends across the Southeast and a weak
trough remains far inland. PWATs are generally under 2 inches, which
is close to normal for this time of year, but more noticeable is the
lack of instability across our area each afternoon (CAPEs struggling
to reach 1,500 J/kg). This will limit the convective potential and
coverage. Have trimmed POPs to only a small portion of our GA
counties Tuesday afternoon, where some convection across northern FL
could move northward. The slight chance POPs remain in the forecast
mainly along the sea breeze corridor and inland Wednesday and
Thursday. Early morning land-breeze formation will likely result in
some convergence along and just off the coast each morning. Storms
forming along this boundary should remain isolated and weak with a
couple of waterspouts the primary concern.
Temperatures will remain above normal due to the warm airmass
already in place, WSW flow through the low/mid levels and subsidence
aloft allowing for plenty of sunshine through midday each day. Heat
indices will top out in the mid to upper 100s each day, with a few
areas possibly near 110 degrees briefly in the afternoon before the
sea breeze moves through and lowers them.
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
Hot and humid conditions will continue through the weekend as
ridging persists overhead and Atlantic high pressure remains at the
surface. A weak cold front may approach from the north Friday or
Saturday, but will likely dissipate before reaching the area.
Afternoon thunder chances across land areas, and morning thunder
chances over the waters, trend closer to climo in the long range,
with dry air/subsidence aloft gradually moderating through the
weekend. High temps will continue to reach the mid-to- upper 90s
away from the immediate coast through the weekend assuming minimal
debris clouds and convection abates until mid-to- late afternoon
A pattern change could come as early as Monday as weak upper level
troughing begins working into the eastern U.S.
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
Expect VFR conditions through at least 18Z Monday. Very low
probability for direct impacts to either terminal from an isolated
shower or possibly thunderstorm, but most likely time frame is
18-21Z this afternoon. Patches of shallow ground fog are possible
at either terminal early tomorrow morning but more substantial fog
that would cause impactful vsby reductions appears unlikely.
Extended Aviation Outlook: VFR will prevail at both sites. Brief
flight restrictions possible with isolated afternoon
showers/thunderstorms mainly late week.
Tonight: Typical summer marine weather is on tap with south to
southwest winds less than 15 kt. Seas 2-3 ft.
Tuesday through Saturday: Atlantic high pressure will allow south to
southwest at 10-15 kt to prevail. Gusts around 20 kt are expected
with the afternoon sea and overnight land breezes. Seas will range
from 1-3 ft, except some occasional 4 footers across the outer