Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Columbia SC
503 am EDT Tuesday Sep 1 2015
an upper level ridge will gradually shift east towards
Florida...while an upper trough will shift southeast from the Ohio Valley
to offshore the middle Atlantic coast. This will ensure that a
relatively dry atmosphere will remain in place over our region
through middle to late week...with some increase in maximum temperatures.
Indications of a back door front and increasing moisture may spell
increasing chances for precipitation by this weekend...along with
slightly cooler temperatures.
Near term /through tonight/...
areas of early morning fog possible...otherwise generally fair
conditions expected. Upper and surface low will continue to track
east further offshore the NC coast. Upper ridge centered to our
southeast will build slightly to the west...while closed low remains over
the Midwest. Upper energy and associated moisture to our south
over Florida prognosticated to continue rotating clockwise around the
west side of the upper high. Latest models indicate the moisture
and associated precipitation will remain south of our forecast
area (fa). Models forecast a relatively dry atmosphere to remain over
our forecast area...though some slight increase in moisture noted south.
Model forecast soundings continue to indicate dry and capped
conditions for our forecast area...appearing to suppress thunder...though
some high resolution model output indicating premise for some
shallow diurnal shower activity possible.
Short term /Wednesday through Thursday night/...
upper ridge will shift west over Florida and the eastern
Gulf...while Midwest closed low opens and shifts southeast towards the
middle Atlantic coast. Upper energy and moisture to our south appears
will get suppressed and ejected to the east/se...remaining south
of our forecast area. Relatively dry air appears will remain in place over
our forecast area...though some slight increase in moisture noted. Slight
chance mainly diurnal probability of precipitation appears OK.
Long term /Friday through Monday/...
31/12z European model (ecmwf) shifts upper closed low from the western Gulf Coast
east into our region...while 01/00z GFS keeps that upper low to
our west but indicates upper trough over the western Atlantic
cutting off and shifting west into our region. Both models
indicate back door front moving into our region with an easterly
low level flow developing and increasing atmospheric moisture. For
now...will accept blend of guidance and ongoing forecast which
generally indicates chance probability of precipitation...and maximum temperatures trending down
Aviation /09z Tuesday through Saturday/...
High pressure in control with a relative dry airmass across the
Still expect periods of MVFR/IFR fog at ags/ogb through 14z. VFR
conditions to return to all taf sites by 14z with light and variable
winds during the daylight hours. Isolated convection possible this
afternoon and evening...but probability too low to include in tafs.
Extended aviation outlook...restrictions possible in mainly early
morning with fog and afternoon and evening scattered showers or