Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Columbia SC
1208 PM EDT Tuesday may 26 2015
continued onshore flow associated with high pressure off the middle-
Atlantic coast will result in moderate to high moisture through
midweek. This will also increase the chance of mainly afternoon
and evening thunderstorms across the area through Thursday. An
upper ridge will become entrenched over the area again during the
Near term /through tonight/...
light onshore flow continues with cumulus beginning to develop
across the southern midlands and csra. Upper level trough will
move through Georgia this afternoon and into the upstate/western
midlands tonight. Current WSR-88D returns indicate light showers
over the southeastern midlands and southern csra. Expect cumulus
to continue developing through the afternoon hours with showers
increasing in coverage and intensity...with thunderstorms
beginning during the early afternoon hours. Thunderstorms will
increase across the northern csra and western midlands this
afternoon as the upper level trough moves into the forecast area.
Expect showers to diminish this evening with loss of
heating...with activity persisting over the western midlands and
northern csra due to the upper level support. With clouds across
the area this afternoon high temperatures will be in the upper 80s
with lows tonight in the middle to upper 60s.
Short term /Wednesday through Thursday night/...
the models display the axis of deeper moisture shifting a bit
farther east and into the forecast area for Wednesday and
Thursday. Expect a greater chance of thunderstorms with possibly
more organization as middle-level shortwave troughing moves into the
area. The GFS and NAM MOS probability of precipitation range from 30 to 60 percent. Used
an average of the MOS for the pop forecast. Leaned toward the
cooler high temperature guidance Wednesday and Thursday because
of cloudiness and showers. Used the guidance consensus for the low
Long term /Friday through Monday/...
the GFS and European model (ecmwf) display high pressure ridging into the area
from the Atlantic during the medium-range period. Aloft...ridging
Friday through Sunday appears to weaken Monday. The GFS...
European model (ecmwf)...and ekd MOS have probability of precipitation 10 to 30 percent Friday through
Sunday...and 30 to 40 percent Monday. The MOS has temperatures
Aviation /16z Tuesday through Saturday/...
stratus and fog have eroded across the area with a few low clouds
remaining in the csra...which will lift over the next hour.
Increasing moisture across the expect showers and thunderstorms
across the area this afternoon and evening...confidence remains
too low to include mention in tafs so will remain with thunderstorms in the vicinity/vcsh
late this afternoon and evening. Low clouds will return to the taf
sites tonight with IFR...possibly LIFR...during the early morning
and sunrise hours.
Extended aviation outlook...early morning restrictions are
possible through the end of the week. There will also be an
increased chance of afternoon/evening showers and thunderstorms
which could reduce ceilings/visibilities at times.