KGSP AFD for the weekend
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 215 pm EST Tuesday: Considerable uncertainty remains over the
handling of the upstream trough axis crossing the Mid-Mississippi
River Valley Friday night. The 12Z GFS continues to feature a 500 mb
low center cutting off and migrating over the Deep South on
Saturday. The GEFS spread is quite large, however, and the NAM/CMC
feature either a more northerly track of the low or an open wave.
Until recently, the ECMWF runs have had a much more progressive,
positive tilt, open wave moving through the Appalachians. Recent ECM
trends, however, have been slightly toward the deeper and more
dynamic operational GFS, and this has some implications for wintry
weather potential over our area this weekend. For now, the forecast
has been nudged slightly wetter through the Saturday night/Sunday
morning period. This keeps mountain northwest flow snow showers
solidly in the forecast Friday night through Saturday night, but
also creates low end potential for a wintry mix east of the
mountains through Sunday morning. Confidence remains very low on
this and ensemble mean solutions still do not support much of any
accumulating snow east of the mountains over the weekend.