Scientific Forecaster Discussion
fxus62 kchs 260608
Area forecast discussion
National Weather Service Charleston SC
208 am EDT Fri may 26 2017
high pressure will linger over the region through this weekend. A
weak cold front is expected to slowly slide over the coastal plain
early next week.
Near term /through today/...
early this morning: no changes needed to the going forecast.
Clear skies and tranquil conditions will prevail.
Friday, mid levels should begin the day zonal with slight rises from
the west during the afternoon hours. Low level flow will remain from the
west-southwest through the day. The combination of full insolation and west-southwest
winds should yield increasing low level thicknesses. High
temperatures are forecast to range in the mid 80s inland to the low
80s across the beaches.
Short term /tonight through Sunday/...
weak ridging aloft will build slowly through the period. At the
surface, elongated high pressure stretching from the Gulf of Mexico
into the Atlantic Basin will remain in control. Though boundary
layer flow will be mainly southwesterly, low-to-mid-level flow will
be westerly, resulting in drier downsloping conditions precluding
mentionable pops for most. The exception is areas near and north of
Lake Moultrie, where some modest destabilization and moisture
pooling associated with a disturbance north of the area may allow
some showers/thunderstorms to scrape the area.
Low level thickness values suggest highs in the mid-90s Saturday and
Sunday, but with some mid level cloud cover and afternoon cumulus
possible, have moderated the forecast both days. Still, with the
seabreeze trapped near the coast, lower-90s can be expected
everywhere except the beaches both days. Afternoon dew points in the
lower 70s Sunday will contribute to heat index values approaching
100 for some areas along the Highway 17 corridor.
Long term /Sunday night through Thursday/...
the surface cold front will approach the area through the first
half of the week as the trough aloft slides east, bringing the
potential for another period of unsettled weather Monday through
Aviation /06z Friday through Tuesday/...
Extended aviation outlook: VFR.
offshore winds will diminish to 10-15 kt overnight, while winds
10 kt or less will become common on Charleston Harbor and
On Friday, southwest winds are forecast to remain gusty, but
less than advisory levels. Wave heights are expected to range
between 1-2 feet within 10 nm and 2-3 feet beyond 10 nm.
Friday night through monday: high pressure will prevail across
the coastal waters into early next week. Moderate breezes will
persist across the waters through the period, with winds
approaching advisory criteria at times mainly for the Charleston
County nearshore waters, where the gradient will be tighter
thanks to a weak disturbance north of the area. Seas will be 2
to 3 feet, with higher seas possible beyond 40 nm at times.
tide levels will trend higher each day as we approach the new moon
and perigee this Friday. Despite the unfavorable wind direction,
minor coastal flooding is possible along mainly the South Carolina
coast with the evening high tide cycles Friday through the