Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 270653
Area Forecast Discussion
National Weather Service Columbia SC
253 AM EDT Thu Apr 27 2017
A frontal boundary approaching from the west today will provide a
chance of mainly afternoon and evening showers and thunderstorms, a
few possibly severe. Fair and warm Friday through Sunday. A front
will provide a good chance of showers and thunderstorms Monday.
Generally fair with seasonal temperatures expected Tuesday and
Wednesday. Another significant weather system will affect the
.NEAR TERM /THROUGH TONIGHT/...
Upper ridge will shift to our east. Upper trough over the Central
CONUS. Main upper energy emerging from the base of the trough will
shift NE into the Midwest/Great Lakes region, remaining mainly to
our north. Surface front will approach from the west. Increasing SW
flow ahead of the front with breezy conditions possible. Indications
are that wind gusts will remain below lake wind advisory criteria.
The SW flow ahead of the front will provide warm temps and
increasing moisture. Associated batch of showers and thunderstorms
expected to approach the CSRA/NW Piedmont this afternoon and early
evening then gradually weaken late this evening and early tonight as
the activity shifts farther east, as main upper energy remains to
our north and with loss of heating. However, indications of moderate
instability and shear provide a threat that a few of the storms
could reach severe limits. SPC has most of our FA in a MRGL risk of
severe today. Hi-Res models indicate convection diminishing as it
pushes into the forecast area with a general window of about 3-6
hours between 21z-03z before instability wanes.
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
Upper high will build off the SE coast, while upper trough deepens
into a closed low well to our west, providing generally fair weather
and warm temps. Increasing low level moisture combined with the warm
temps may provide a slight chance of diurnal convection Sat/Sun.
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
GFS/EC continue to appear in good agreement with overall pattern.
Upper low to shift NE from the southern Plains into the upper
Midwest Monday. A front and associated band of convection will shift
east into our region Monday/Mon nt. Front appears will shift
offshore Tue, possibly returning as a warm front late Wed ahead of
the next approaching upper trough and cold front, that both
models indicate could affect our region by Thu. Generally
accepted guidance blend thru the period.
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
Generally expect VFR conditions through 12z then possible MVFR
cigs moving into the CSRA through 16z or so.
Moisture will be on the increase today with strengthening
southerly flow between offshore high pressure and an
approaching weak cold front. Fog not expected to be an issue
this morning with persistent boundary layer winds from a 30
knot low level jet. HRRR and MOS guidance suggesting
stratocumulus will move into the region after 12z. The NAM
Bufkit momentum transfer tool indicated gusts 20 to 25 knots
during the afternoon. Lingering mid-level capping as indicated
by the models may help limit thunderstorm coverage as front
pushes into the region. However think some showers will reach
terminals around 00z so included VCSH at 23z AGS/DNL and 00z
EXTENDED AVIATION OUTLOOK...Widespread IFR stratus and fog
associated with the remnants of a front may occur during the
early morning hours Friday and Saturday. Widespread IFR stratus
may occur mainly during the early morning hours Sunday with
increased moisture ahead of a cold front. Gusty winds and
restrictions in thunderstorms may be an issue with the front