Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Columbia SC
1025 PM EDT Tuesday Jul 22 2014
a weak stationary front and coastal trough will provide a focus
for scattered to numerous showers and thunderstorms. An upper
trough will approach the area and bring a cold front into the
region later this week.
Near term /through Wednesday/...
WV loop shows closed low along the central Gulf Coast gradually
beginning to retrograde and this will continue overnight into
Wednesday. Have continued with high chance/low likely probability of precipitation for the
afternoon. Muggy temperatures overnight with readings in the
middle 70s. Slightly warmer on Wednesday with highs in the lower 90s.
Short term /Wednesday night through Thursday night/...
the upper level low along the Gulf Coast will slowly fill through
Thursday. However...short wave energy moving southeast from Great
Lakes region will sharpen the upper trough over the eastern states
and drive a cold front toward the region Thursday.
Precipitable water remains high through the period with values
around 2.0 inches at times. Model spectrum and guidance showing
quite a range with probability of precipitation Wednesday although latest guidance suggested
lower probability of precipitation as moisture decreases and surface trough weakens. We kept
low chance probability of precipitation for Wednesday afternoon. There should be a better
chance for convection Thursday given short wave energy crossing the
area and moderate instability along with dry air aloft. Weak
moisture convergence may limit convective coverage. Kept chance probability of precipitation
Thursday with highest probability of precipitation across the north midlands.
Should see highs in the lower 90s Wednesday. Thursday should be a
little warmer with southwest low level flow and weak warm advection
ahead of approaching cold front.
Long term /Friday through Tuesday/...
models continue to trend toward an amplification of the long wave
pattern with a ridge in the west and a trough in the east.
The medium range models show an upper trough over the eastern Continental U.S.
With a ridge over the western states Thursday night into Friday
night. The cold front across the region becomes diffuse though
moisture and instability lingers.
By Saturday the ridge in the west begins to build across the
southern states. The upper pattern once again amplifies early next
week with a ridge in the west and a deep trough. This should push
another cold front toward the region on Tuesday.
We kept a chance of showers/thunderstorms Friday diminishing to isolated for
Saturday. Chance probability of precipitation were retained for Sunday through Tuesday.
Temperatures should be near normal with highs in the low/middle 90s and
lows in the upper 60s to lower 70s.
Aviation /03z Wednesday through Sunday/...
variable conditions to continue through the taf period.
Showers becoming more widely scattered across the area late this
evening...with isolated thunderstorms over the csra. Will keep
mention of vcsh at cae/cub/ags/dnl into the early morning given
later radar trends as well as the current moist atmosphere and a
stalled front in the vicinity. Winds through the period will be
mainly easterly around 5 knots or less. Once again...BUFKIT shows
abundant low level moisture overnight and expect some fog/stratus to
once again develop over much of the region including the taf sites.
More showers developing again towards the end of the taf period
Wednesday...but not enough confidence to mention at this time.
Extended aviation outlook....cig/vsby restrictions possible through
Saturday due to plenty of low-level moisture across the area.
Another cold front will approach the region Thursday into
Friday...which could bring additional storms to the region.