Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 231557
Area Forecast Discussion
National Weather Service Columbia SC
1157 AM EDT SAT JUL 23 2016
High pressure will be in control of the region through early next
week. A weak frontal boundary will approach from the north around
the middle of next week. Mostly dry weather and hot temperatures
this weekend will give way to scattered showers and thunderstorms
next week. Temperatures should remain above normal.
.NEAR TERM /THROUGH TONIGHT/...
Under mostly clear skies temperatures have already risen into the
lower 90s at most locations with a few cumulus beginning to
develop. Upper level ridge continues pushing into the eastern US
with weak southwesterly flow at the surface. Although instability
is moderate there is drier air at the mid levels with minimal
upper level support. As such expect a slight chance of
thunderstorms this afternoon and evening with convection rapidly
dissipating with sunset. High temperatures this afternoon will be
in the upper 90s to low 100s with lows tonight in the mid 70s.
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
The mid/upper level ridge axis will continue to extend eastward
into the Carolinas through Sunday with temperatures climbing
another couple of degrees by Sunday afternoon. Expect temperatures
to approach the century mark at many locations. Heat index values
will range from 105-109 degrees. This will be close to heat
advisory criteria but will likely fall slightly short. Isolated
diurnal convection possible with moderate instability Sunday
afternoon and evening...although subsidence from the upper ridge
may limit convection.
.LONG TERM /MONDAY THROUGH FRIDAY/...
Both GFS/ECMWF indicate the the eastward extent of the mid/upper
level ridge will begin to weaken and retrograde westward back over
the central plains/four corners region by mid/late week. A surface
front will also approach the region stalling out north of the
forecast area Mon/Tue. Another stronger s/w will try to push a
front slightly farther southward toward the cwa by late week.
Looks as though any front through the week will remain north of
the area and gradually weaken. Our forecast area will remain south
of the frontal boundary in the hotter air and PW values ranging
from 1.5 to 20.0 inches...so cannot rule out isolated/widely
scattered thunderstorms each afternoon/evening across the CWA.
Temperatures through the period will remain above normal through
the end of next week with highs in the mid 90s to around 100
degrees and lows in the 70s.
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions expected, outside of convection, through the TAF
Upper level ridging will continue moving into the TAF sites
through the period with light southwesterly flow at the surface.
Cumulus will develop through the afternoon and evening
hours...however the potential for thunderstorms at any TAF site is
too low for mention. Convection which develops will dissipate with
sunset with some mid level debris cloudiness overnight. With the
debris cloudiness and a low level jet around 25 knots overnight
fog is not expected.
EXTENDED AVIATION OUTLOOK...Low confidence in restrictions
in afternoon and evening convection each day. Low potential for
early morning fog/stratus each morning...mainly at AGS/OGB.