Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 242325
Area Forecast Discussion
National Weather Service Columbia SC
725 PM EDT Fri Mar 24 2017
High pressure will shift to our east Saturday ahead of a front that
will move into our region late Saturday night and Sunday. A series
of systems will affect our region next week, providing a chance of
showers, and possibly thunderstorms, at times. Above normal
temperatures expected through the period.
.NEAR TERM /UNTIL 7 AM SATURDAY MORNING/...
An upper level ridge over the southeastern states this
afternoon will gradually move east overnight. Surface high
pressure off the Mid-Atlantic coast will continue to ridge into
the Carolinas and Georgia through tonight. Dry weather will
continue overnight. An onshore flow will bring increasing low
level moisture into the region tonight. Should see an increase
in late night clouds with lows in the upper 40s to mid 50s.
.SHORT TERM /7 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
Upper and surface high to slip to our east Saturday. Moisture
recovery appears shallow. Isolated showers cannot be ruled out
but chances appear to low to include in the forecast at this
time. Upper and surface lows over the Central Plains will move
NE towards the Great Lakes, with surface front moving into our
region late Saturday night and Sunday. Main upper dynamics will
remain to our north, and moisture appears will be relatively
limited with the system in our region, with precipitable water
(PW) values progged to only be around 1.2-1.3 inches. Weak
instability, diurnal heating, and frontal and possible sea
breeze convergence, could provide chance pops mainly Sunday
afternoon/early evening per model consensus, with thunder
possible given projections of weak instability.
.LONG TERM /MONDAY THROUGH FRIDAY/...
Front appears could hang up and become ill defined over the region
Monday, with band of PW values 1.2-1.3 inches remaining over the
region. Not much trigger Monday aloft, but diurnal heating and any
convergence along old front or sea breeze could provide a slight
chance showers/isolated thunder. Upper disturbance and surface
boundary progged to roll through Monday night/Tuesday time frame.
This upper energy appears will be a little farther south and a
little stronger for our region than the previous upper trough. PW
values progged to only be around 1.3 inches. Latest model guidance
appears to be trending up on POPs a tad. For now, chance POPs look
reasonable, including thunder with weak to moderate instability
projected. Both GFS and EC indicate some upper ridging over the SE
CONUS Wednesday as an upper low moves into the southern Plains,.
though a surface front appears to remain in our vicinity, to
presumably stall and eventually lift back north as a warm front
ahead of the next system. The models take the upper low to the NE
with moisture affecting our region by Thu/Fri, though confidence of
model timing and position of closed upper systems is limited late in
the forecast period. Models blend used.
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions are generally forecast through Saturday.
Surface high pressure centered offshore will continue to ridge
into the region overnight, providing an onshore flow.
Increasing moisture will result in SCT/BKN clouds with bases
5kft to 6kft. Diminishing winds tonight combined in a continued
onshore flow could result in MVFR cigs/vsbys by early Saturday
morning, but confidence is low since MVFR conditions are not
well supported by the MOS or the HRRR. Have only indicated MVFR
cigs/vsbys 11Z to 15Z at AGS and DNL where enhanced moisture
from the Savannah River could play a role. VFR conditions return
to all TAF sites by late morning Saturday as heating and
vertical mixing commences.
EXTENDED AVIATION OUTLOOK...CIG/VSBY restrictions possible
Sunday through Tuesday in morning fog and stratus associated
with an onshore flow. Deeper moisture and a frontal system near
the area may help support scattered showers and thunderstorms
with associated restrictions Sunday and Monday.