Area Forecast Discussion
Issued by NWS Charleston, SC
FXUS62 KCHS 260804
Area Forecast Discussion
National Weather Service Charleston SC
404 AM EDT TUE JUL 26 2016
Atlantic high pressure will prevail through much of the week while
a weak trough persists inland.
.NEAR TERM /THROUGH TONIGHT/...
Pre-dawn: The mainly clear skies overnight should continue to
prevail through daybreak, although a few pockets of stratocu and
patchy thin cirrus will likely be seen once the sun comes up.
Temps for most in the mid 70s inland to the lower 80s at the
Today: Strong and persistent deep layered ridging will continue
across the forecast area. Warm mid level temps, extensive dry air
and subsidence aloft will again to combine to negate development of
diurnal convection this afternoon across most of the forecast area.
There will be some low level moisture advection across the Florida
Panhandle and southwest Georgia this afternoon, however the better
instability and the Gulf Coast sea breezes will be removed from our
southern Georgia zones. It is unlikely isolated convection reaches
this region toward late afternoon but did maintain some slight
chance pops closer to the Altamaha River. We went with a dry
forecast at Savannah given forecast sounding trends and consensus
of dry returns from most of the convection allowing models. This
is not to say a spotty shower or tstm could develop just about
anywhere along the Georgia sea breeze corridor this afternoon, any
localized updrafts should be brief and short-lived. Persistent
temp forecast with mid 90s and a few upper 90s further inland.
Heat indices will reach 102 to 105 degrees in most areas this
Tonight: Quiet weather will persist as mid level ridging and the
surface synoptic pattern remain stagnant. Skies will be mainly
clear some late night showers off the coast once again. No changes
to forecast low temps...mid to upper 70s once again.
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
Strong mid/upper level ridging directly over the area will continue
into the second half of the workweek. At the surface, Atlantic high
pressure dominates locally with troughing well inland. POPs will
remain below climo values given the amount of subsidence aloft, with
only slight chance mainly along the sea breeze corridor Wednesday
and Thursday, and mentionable POPs left out Friday as the majority
of global model operational and ensemble members keep the area dry
Persistent heat remains the main weather story for the forecast
period. Heat indices will top out in the mid-100s daily, and though
some coastal areas will briefly approach heat indices of 110 right
along the seabreeze, no heat advisories are expected through the
period. Muggy overnight conditions can be expected with lows only
dipping to near 80 along the coast and upper 70s inland.
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
Ridging overhead will weaken heading into the weekend and POPs will
return closer to climo levels with a warm and humid airmass in place
at the surface. The ridge will slide off the Southeast Coast Sunday
and modest height falls aloft will bring more unsettled weather
early next week. A cold front associated with low pressure lifting
across the Great Lakes may reach as far south as the Carolinas
before dissipating Monday and Tuesday. Global models currently focus
moisture pooling and enhanced convective initiation near this front
across North Carolina and the South Carolina Upstate Monday and
Tuesday, and with 700mb steering flow gradually shifting more WNW,
some of this activity could advect into our area during this time.
POPs well into the chance range have been introduced for the early
part of next workweek, especially across and north of the Charleston
Temps will remain well above normal through the period as the warm
and humid airmass remains anchored over the area with ample sunshine
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
VFR through 06Z Wednesday, with little or no chance of any convection
this afternoon at either terminal.
Extended Aviation Outlook: VFR will prevail at both sites. Brief
flight restrictions possible with isolated afternoon
showers/thunderstorms mainly over the weekend.
Day to day changes have become quite subtle with a synoptic
pattern this steady. The forecast through tonight is one of
persistence with s to sw flow peaking at 15 kt late day and
overnight and ebbing below 10 kt from mid morning through the
early afternoon hours. Through tonight, seas will generally
average 2 to 3 ft. Showers and tstms are possible mainly seaward
from the pilot buoys early prior to daybreak this morning and
again late tonight.
Wednesday through Sunday: Atlantic high pressure will prevail
through the period with south-southwest winds mainly 10 to 15 knots
and seas generally 2 to 3 feet, with gusts to 20 kt and seas to 4
feet across the outer Georgia waters during the early morning hours.
A stray early morning shower/thunderstorm is possible through the
end of the workweek, with thunderstorm chances and the
associated threat for frequent lightning increasing this weekend.