Area Forecast Discussion
National Weather Service Columbia SC
623 AM EST Wed Mar 8 2017
A digging northern stream shortwave trough will cross the Ohio
Valley on Saturday night and then cross the Carolinas on Sunday
bringing a cold front through the region. Ahead of the trough,
strong south to southwesterly 850mb flow around 40-50 knots will
provide strong moisture transport into the forecast area and
precipitable water values surge to around 1.25 inches ahead of the
approaching front. Differences arise in the track of the surface
low with the GFS being further north from near ATL to CAE to ILM
while the ECMWF is further south along the gulf coast and northern
Florida. The further south track would allow for a stronger cold
air damming scenario and could mean the possibility of some wintry
precipitation in the far northern Midlands and certainly in NC while
the GFS track would support warmer temps and possibly more
instability and the chance for convection over part of our area in
vicinity of the CAD boundary.
Given the spread among the deterministic models and ensembles and
generally low confidence forecast at this time will plan to make
little changes to this part of the forecast. However, this will be
something to watch and it would appear that there is a good chance
that we would see significant rainfall with this event and pops will
likely need to be raised higher as the event approaches. Also have
trended a bit cooler in the most confident area of cold air damming
across the northern Midlands.