Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area Forecast Discussion
National Weather Service Charleston SC
638 PM EDT WED JUL 27 2016

Atlantic high pressure along with an inland trough will prevail into
early next week.


KCLX reflectivity data shows the resultant sea breeze is finally
picking up steam and moving inland. Dewpoints are pooling into the
mid-upper 70s along the coast as it moves inland yielding heat
indices 105-108. Warm and humid conditions will persist overnight
as expansive high pressure holds firm. Lows will range from the
mid-upper 70s inland to the lower 80s at the coast. 

Changes for the early evening update include:
* Introduced some thermal local effects into the gridded
  forecasts. Nudged overnight lows up a few degrees along the
  Broad and Savannah Rivers as well as Lake Moultrie and the far
  eastern portions of Lake Marion.
* Lowered pops area wide to <10%.

The rest of the forecast is on track.


Atlantic high pressure will continue to extend westward over the
forecast area while a trough persists inland. This pattern will
maintain warmer than normal temperatures with highs generally in the
upper 90s inland but even near 90 at the coast. Heat indices will
peak around 105 degrees for most areas each afternoon, although
could briefly reach near 110 near the coast as the sea breeze pushes
inland. Unfortunately there will not be much relief at night either
with lows in the mid to upper 70s most places and closer to 80 at
the coast. Showers and thunderstorms will be few and far between
with the best chances coming Saturday when some deeper moisture
approaches from the northwest.


West-southwesterly low level flow keeps a warm and humid airmass in
place through the long term period. Increasingly unsettled weather
will ensue as the ridge continues to slide off the Southeast coast
and deep-layer moisture increases early next week. Global model
solutions begin to diverge significantly heading into the middle of
next week as a deteriorating cold front may approach the area
Tuesday night into Wednesday. POPs have been increased well into the
chance range, especially north of I-16, to account for this. Temps
will remain at least a few degrees above normal through the



Extended Aviation Outlook: Brief flight restrictions will be
possible with afternoon showers/thunderstorms this weekend.


Tonight: The deep layer ridge and Atlantic surface high pressure
will bring south to southwest winds averaging 15-20kt this evening
and overnight. Seas will average 2-3 ft nearshore waters and
building to 3-4 ft offshore waters.

Thursday through Monday: Atlantic high pressure will prevail
along with an inland trough. This pattern will favor south to
southwest winds that will gust near Advisory levels /25 knots/ at
times, mainly along/off the Charleston County coast during late
afternoon/evening due to the sea breeze. Seas mostly 3 feet or
less, but 4 feet at times near the Gulf Stream.






National Weather Service Glossary of Abbreviations