Area Forecast Discussion
Issued by NWS Charleston, SC
FXUS62 KCHS 241049
Area Forecast Discussion
National Weather Service Charleston SC
649 AM EDT SUN JUL 24 2016
Atlantic high pressure will prevail through much of the week while
a weak trough persists inland.
.NEAR TERM /THROUGH TONIGHT/...
Update: No major changes were made to the previous forecast.
Waterspouts will again be possible in any showers/storms offshore.
Today: The area will remain between Atlantic high pressure to the
east and an inland trough east of the mountains. This will
maintain a warm southerly flow regime which will boost
temperatures to above normal levels again with mid to possibly
upper 90s inland and closer to 90 near the coast. Dewpoints should
lower to around 70/lower 70s most places away from the coast
during peak heating and thus heat indices should mostly stay 105
degrees or less. The sea breeze looks to be the main forcing for
convection and thus we maintained rain chances at 20 percent,
although they could ultimately be a bit higher depending on
mesoscale boundary interactions. Instability and DCAPE will be
sufficient for a few storms to potentially produce severe wind
Tonight: Any lingering convection should diminish early with
mostly dry conditions overnight as upper level low pressure to the
south moves west into the Gulf of Mexico. Some light patchy fog
will be possible, mainly where rain recently falls and skies
clear. Lows will mostly range from the mid 70s inland to near 80
at the coast, although some of the normally cooler inland spots
could reach the lower 70s.
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
Fairly quiet weather expected through the period as broad mid/upper
level ridging maintains influence over the local area. The surface
pattern will be rather stagnant, with Atlantic high pressure the
dominant feature and a weak trough inland. Dry air in the mid levels
and weak subsidence will keep convective coverage pretty limited,
especially Monday when precipitable water values drop to under 1.4
inches. Perhaps the more active day of the bunch (likely still low
coverage) would be Wednesday when moisture is a bit better. Current
forecast features no more than 20% chances. Organized severe threat
is low, but certainly cannot rule out an isolated severe storm this
time of year.
Gradual warming trend will be underway with high temperatures in the
low/mid 90s Monday warming to mid/upper 90s by Wednesday. No heat
advisories expected as heat indices only peak in the 100-105
range. Lows mainly in the mid to upper 70s.
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
The synoptic pattern will change very little in the long term
period. Mid/upper level ridging will persist through late week. At
the surface, the primary features will be Atlantic high pressure and
a trough of low pressure inland. A weak front may approach late
week, however it will likely stall and eventually dissipate before
reaching the local area. Fairly typical summertime PoP scheme in the
forecast, generally 20-30% chances. Coverage will peak in the
afternoon and evening when instability is greatest. Another period
of above normal temperatures with highs forecast in the mid/upper
90s and lows in the mid/upper 70s.
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
VFR to prevail for the most part through 12Z Monday. Isolated
afternoon showers/thunderstorms could impact the terms, mainly
16-21Z, as the sea breeze pushes inland.
Extended Aviation Outlook: Brief flight restrictions possible each
afternoon with isolated showers/thunderstorms. Otherwise, VFR.
Today/Tonight: Atlantic high pressure will prevail with winds
remaining mostly from the south. Speeds will be 15 kt or less,
highest early this morning and this afternoon near the coast with
the sea breeze. Seas mainly 2-3 feet, highest near the Gulf
Stream. Also, conditions appear somewhat favorable for waterspouts
again. May issue a Marine Weather Statement later this morning to
Monday through Friday: Atlantic high pressure will persist while a
weak trough sits inland. South/southwest winds will generally be 15
knots or less, peaking in the afternoon with the sea breeze
circulation and then again overnight. No small craft advisories
anticipated. Seas 2-3 feet on average.