Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 231500
Area Forecast Discussion
National Weather Service Columbia SC
1100 AM EDT THU JUN 23 2016
A cold front sinking southward and into Virginia today and North
Carolina Friday will move into the forecast area Friday night. The
front will remain near the area during the rest of the weekend.
It will be hot ahead of the front today and Friday.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Temperatures are rising quickly this morning as CAE has already
reached 92 degrees and most other locations are in the upper 80s
to around 90. Surface map shows high pressure centered along the
Gulf coast while a frontal boundary was located across the Ohio
Valley into the Mid-Atlantic region. Water vapor imagery shows a
large area of dry air extending from Texas eastward across the
lower MS valley into the southern Appalachians and South
Regional radar shows a convective complex moving southeastward
across WV/VA which will remain well north of our area. Expect a
hot day under mostly sunny skies, except for some lingering cirrus
into early afternoon. Stronger instability looks to be confined
mainly in the northern Midlands where precipitable water values
are higher. Forecast soundings indicate a strong capping
inversion which should limit any convection from initiating
despite the very warm surface conditions. Will continue with a dry
forecast today across the area although an isolated storm cannot
be ruled out in the far northern Midlands.
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
Moisture will remain limited tonight with surface ridging south of
the region. However, moisture and instability associated with a
mid-level shortwave trough may help support thunderstorms mainly
in the north section. Forecasted just slight chance pops because
of the weak support and nocturnal cooling. Boundary layer wind
should help hold up temperatures and we leaned toward the higher
low temperature guidance.
The thunderstorm chance should increase as the cold front sinks
farther southward and moves into the forecast area Friday night.
The models also indicate upper ridging suppressed farther
southward. Still, with surface ridging south of the area limiting
moisture, thunderstorm coverage may remain limited. There is also
uncertainty with the timing of mid-level shortwave troughs. We
leaned toward the higher guidance pops because of convergence
ahead of the front and into the lee-side trough and expected
strong instability, but still kept the pops in the chance
category. Forecasted the highest chance in the north section
closer to greater upper-level support. The models depict strong
instability Friday into Friday night. The NAM displayed surface-
based LI`s -8 to -9. Thunderstorms with damaging wind and hail may
occur. Forecasted the greatest chance ahead of the front and close
to the time of maximum heating late Friday afternoon and evening.
H85 westerly flow and temperatures near 22 C ahead of the cold
front plus recent verification favored the higher temperature
guidance Friday. Followed the guidance consensus for the
temperature Friday night.
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
The GFS and ECMWF display a front stalled near the forecast area
through Tuesday with another cold front nearing the area
Wednesday. The models have upper ridging near the forecast area
Saturday and Sunday shifting farther westward with a difluent
height pattern during the rest of the period. The pattern
supports chance pops. The GFS and ECMWF MOS have pops 20 to 50
percent through the medium-range period. The MOS indicates
temperatures near climatology.
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
High confidence for VFR conditions through the 24 hour TAF period.
High pressure will remain centered south of the TAF sites and a
cold front will remain north of the area. Scattered high level
clouds across the Midlands. Winds have been a bit more westerly
this morning than expected but should back around to the southwest
with gusts near 20 knots during the afternoon as deep mixing
commences. Convection late this afternoon and this evening should
remain north of the TAF sites.
EXTENDED AVIATION OUTLOOK...The chance for mainly diurnal convection
will increase Friday through Monday as a frontal boundary stalls
in the area.