Area Forecast Discussion
Issued by NWS Charleston, SC
FXUS62 KCHS 241339
Area Forecast Discussion
National Weather Service Charleston SC
939 AM EDT SUN JUL 24 2016
Atlantic high pressure will prevail through much of the week while
a weak trough persists inland.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Minor adjustments were made for the late morning update. Influences
from the upper ridge will hold firm today as a TUTT low moves
across Florida. Expect only isolated showers/tstms this afternoon,
mainly along/ahead of the sea breeze. Highs will range form the
upper 90s inland to the upper 80s at the beaches. Dewpoints will
tend to mix out a bit during peak heating, except along the lower
South Carolina coast where dewpoints will pool back into the upper
70s/near 80 as the resultant sea breeze moves inland. Will likely
see heat indices spike into the 106-109 range in the Beaufort to
Downtown Charleston to McClellanville corridor as this occurs.
This is below the 110 Heat Advisory criteria. Again, we caution
external users on the use of bad dewpoint data from area AWOS
units an automated plots of heat index.
Although convection will remain fairly isolated, an isolated
strong/severe tstm can not be completely ruled out with elevated
DCAPE in place.
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
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.
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
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 /14Z 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.
A risk for isolated waterspouts will linger through late morning.
Visible satellite and radar already show several well defined
cloud lines offshore. The risk will gradually diminish by early
afternoon as the sea breeze begins to take shape along the
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.