From RAH:
**********cut from LR discussion*******************
The low-level
flow will quickly turn S/SE on Wednesday as the
surface high moves off the Mid-Atlantic coast. So high temperatures,
while cooler than Tuesday, will still be slightly above
normal, in
the upper-50s to mid-60s. Expect increasing clouds from the west as
a southern stream
shortwave moves from the Central Plains into the
TN Valley on Thursday and Thursday night. Both the
GFS and
ECMWF
also depict a surface low riding along the
front, which will lift
back north as a warm
front. This unfortunately
likely means a wet
and chilly Thanksgiving is on tap for the area. However, exact
details are still uncertain as the
ECMWF depicts a more wound-up
area of low pressure moving well to our north and west, while the
GFS shows multiple waves of low pressure moving directly over the
Carolinas on Thursday and Thursday night.
A farther north track like
the ECMWF/EPS would result in less widespread rain but more of a
convective threat that ends Thursday evening, while the GFS/GEFS
produce heavier rain but less instability (especially north) with
rain continuing into early Friday. As a result, the temperature
forecast is also highly uncertain, so for now take a middle of the
ground approach with forecast highs ranging from upper-50s far NW to
upper-60s far SE.