Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 052309
Area Forecast Discussion
National Weather Service Columbia SC
609 PM EST Mon Dec 5 2016
A storm system along the Gulf Coast will move northeastward to
the Ohio valley spreading widespread rain over the forecast area
tonight into Tuesday. Dry high pressure will briefly build across
the area for Wednesday. Another cold front will cross the region
Thursday bringing much colder air for the end of the week.
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Rain will overspread the forecast area tonight. The water vapor
imagery indicate upper lift upstream which should reach the
forecast area later tonight. The models depict increasing
isentropic lift with a strong h85 jet developing. Forecast categorical
pops. Followed the SREF mean rainfall amounts. Expect little
temperature change with the cloud cover and rainfall.
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Upper low, currently near Tex/Mexico, will shift NE through the SE
CONUS/Mid Atlantic states through Tuesday. Satellite water vapor
imagery confirms a good tap of tropical moisture from the E PAC
ahead of the system. As upper and surface low move NE, upper lift
and isentropic lift combined with abundant atmospheric moisture
expected to provide another batch of widespread rain overspreading
our region through early Tuesday. In situ wedge will develop at the
surface in response to the rainfall, with a typical secondary low
developing near the coast. Wedge boundary will lift north some as a
warm front, due to a strong SW 50 kt low-level jet. Some question as
to how far north the wedge boundary/warm front can get. Some
possibilities that the warm front could move into our southern FA.
Associated instability and shear could provide a severe threat
across that area. Bulk of precipitation expected to shift east of
our FA by late afternoon. Behind the departing system, drier air
will move in aloft late Tuesday into Wednesday, but low-level wedge
and associated low cloudiness could be slow to scour out Tuesday
night/Wednesday, with inverted surface trough lingering over the
.LONG TERM /THURSDAY THROUGH MONDAY/...
Upper trough will swing from the central CONUS to the E CONUS
Thu/Fri, ahead and south of which an upper impulse will ride across
the southern tier of states and across our region Thursday. A cold
front will move through our region Thursday. Models indicating
limited moisture with the system, with the most recent guidance
blend confining slight chance pop to the N FA. Behind the front,
cold dry polar high pressure will shift into the SE CONUS. Breezy
conditions possible Thursday and Thursday night. A lake wind
advisory may be needed. The center of the high is expected to be
overhead by Saturday morning with appearance of good radiational
cooling conditions. Long range MOS projected lows in the mid 20s.
Will undercut guidance a little as those numbers may be a little
high as they are skewed towards climatology that far out. Daily
record low for Columbia for Dec 10th is 20, and for Augusta is 16.
Latest GFS seems to be coming around more towards the EC, with
indications of a slow moving system affecting the region late
Sunday into early next week. Used guidance blend.
.AVIATION /23Z MONDAY THROUGH SATURDAY/...
Latest regional radar composite indicating light rain beginning to
move back into the Midlands and CSRA. Expect widespread IFR
conditions with rain tonight continuing through the rest of the
TAF period. The water vapor imagery indicated upper lift upstream
that will move into the area tonight. An associated h85 jet will
also overspread the area. Shear will be on the increase associated
with this jet with the wedge front just south of the area.
Followed the NAM and forecasted LLWS developing. There may be
thunderstorms during the 10z to 18z time frame associated with the
low-level jet and cooling aloft ahead of an upper trough. However,
the chance was too low to include in the terminal forecasts at
EXTENDED AVIATION OUTLOOK...
Widespread IFR conditions may continue during the rest of Tuesday
and also Tuesday night. The front will be east of the forecast
area Tuesday night but some lingering troughing and high low-level
moisture combined with nocturnal cooling may result in
significant fog. Another cold front may bring more showers and
associated restrictions Thursday. Breezy conditions may also be
associated with the front.