Scientific Forecaster Discussion
fxus62 kchs 200308
Area forecast discussion
National Weather Service Charleston SC
1008 PM EST sun Feb 19 2017
high pressure will extend across the region through the week. A cold
front will impact the area Saturday and be followed by high pressure
Near term /until 6 am Monday morning/...
late this evening: no changes needed to the going forecast.
Clear skies prevail and temperatures are falling into the mid
50s in many areas. Lows still look on track for the upper 40s
for most areas away from the coast with a chance for some mid
40s well inland.
Tonight: conditions will be quiet/dry through the overnight
period. Deep-layered high pressure will build over the southeast
behind a mid/upper lvl trough of low pressure departing over
the western Atlantic, supporting strong radiational cooling over
the area as winds become light/calm under clear skies. In
general, lows will dip into the upper 40s inland to low/mid 50s
near the coast.
Short term /6 am Monday morning through Wednesday/...
Monday and tuesday: an impressive deep layered ridge will hold
across the eastern U.S. Through Tuesday. Strong subsidence coupled
with warming mid-level temperatures will maintain above normal
temperature with highs warming into mid-upper 70s away from the
coast each day. Lows Tuesday morning will drop into the lower-mid
50s with upper 50s along the coast. Highs each day will be tempered
a bit by varying amounts of cirrus, but would not be surprised to see
a few locations hit the 80 degree mark, especially across interior
southeast Georgia. Weak isentropic assent will initiate early
Wednesday morning as high pressure shifts offshore of the mid-
Atlantic coast and subtle coastal troughing forms off the northeast
Florida coast, but any risk for measurable rainfall will remain
displaced well to the west.
Wednesday: moisture return and weak isentropic assent will dominate
as high pressure shifts farther offshore into the Atlantic. Not
overly impressed with the chances for measurable rainfall given
model soundings still show lingering subsidence, so slight chance
pops will be maintained. High will once again warm into the mid-
upper 70s away from the beaches.
Long term /Wednesday night through Sunday/...
Atlantic high pressure will generally prevail until a cold front
likely moves through Saturday or Saturday night. An upper trough
combined with a surface coastal trough should lead to some showers
Wednesday. Then more showers, and possibly some weak thunderstorms,
are expected Thursday/Friday given the onshore flow/sea breeze and
increased instability. A cold front will then approach Friday night,
possibly pushing through as early as Saturday morning, and
additional showers/storms are possible. Cooler/drier high pressure
should then return for the end of the weekend. Temperatures will be
above normal through the period, possibly meeting/exceeding record
levels mid to late week away from the coast.
Aviation /03z Monday through Friday/...
VFR conditions will prevail at both chs and sav terminals through
Extended aviation outlook: VFR.
this evening and tonight: winds/seas will remain well below Small
Craft Advisory levels as a mid/upper lvl trough of low pressure
exits over the western Atlantic and is replaced by deep-layered high
pressure. Northwest winds will prevail early, then veer to north
late with speeds peaking near 10-15 kt. Seas will range between
Monday through friday: east to northeast winds will prevail through
Tuesday before veering to a more southerly regime Wednesday through
Friday as high pressure shifts out into the open Atlantic. There
significant concerns through the period.