Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 300248
Area Forecast Discussion
National Weather Service Columbia SC
1048 PM EDT Sat Apr 29 2017
High pressure ridging into the forecast area from the Atlantic
will dominate through Sunday and help keep any thunderstorms
mainly associated with heating isolated. The next cold front
will bring showers and thunderstorms Monday. Mainly dry weather
is forecast behind this front Tuesday and Wednesday. Another
significant weather system will impact the region Thursday and
.NEAR TERM /UNTIL 7 AM SUNDAY MORNING/...
Showers and thunderstorms have mostly dissipated across the
Upstate with mid and high clouds crossing the forecast area.
Temperatures have already cooled into the mid and upper 70s with
winds remaining southerly at 5 to 10 mph. With the winds
persisting overnight and plenty of low level moisture across the
region will expect stratus to develop over the next several
hours...however the potential for fog remains low. Overnight
lows remain on track for upper 60s to around 70.
.SHORT TERM /7 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
The upper ridge will weaken a bit Sunday as a cold front
approaches from the west, but temperatures will remain warm with
highs in the mid 80s to lower 90s. Heating may help support
showers or thunderstorms Sunday afternoon. The moisture increase
and convergence ahead of the front may also help cause
thunderstorms late Sunday night. However, the chance should be
limited because of shallow moisture Sunday and nocturnal cooling
Sunday night. Kept slight chance pops through 5 AM Monday
morning, then increased chances from west to east through the
early morning as the front moves closer to the area.
A deep closed upper low will lift north into the Great Lakes
region Monday with an associated cold front pushing into the
forecast area Monday afternoon and evening bringing
thunderstorms and moderate rain. Some storms could be severe
given lifted indices -6 to -8, and shear of 35 to 40 kts. NAM
precipitable water values have increased to almost 2 inches.
Strong winds, large hail and heavy rain will be the biggest
threats. South-southwest surface winds will also be breezy
during the day, and a Lake Wind Advisory may need to be issued.
.LONG TERM /TUESDAY THROUGH SATURDAY/...
Stable and dry conditions return behind the front Tuesday, and
temperatures will be slightly cooler with highs only in the mid
70s to low 80s. There is a slight chance of showers and
thunderstorms late Wednesday with a warm front ahead of the next
system. The models diverge beyond this point. The 00Z ECMWF
lifts another low from the southern Plains northward through
the Ohio Valley and into the eastern Great Lakes on Thursday and
Friday. The 12Z GFS takes the low through the lower Mississippi
Valley and eventually into the southern Appalachians. The 12Z
Canadian is somewhere between the EC and GFS solutions. There is
a conses though that Thursday will see another round of
thunderstorms and moderate to heavy rain. Friday and Saturday
are much more uncertain depending on the track of that low, so
kept a chance of showers and thunderstorms Friday, and a slight
chance on Saturday. With deep troughing over the eastern U.S.
during this period, temperatures will be near to below normal
with highs in the mid 70s to low 80s on Thursday and then only
in the low to mid 70s going into next weekend.
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
VFR conditions will persist through the evening...with southeast
winds 5 to 10 knots and widespread high level clouds.
Models indicate low clouds developing 05Z to 08Z given abundant
low level moisture. Have indicated MVFR/IFR conditions
beginning 06Z. Went with persistence with restrictions
lingering into early Sunday afternoon. With mixing and heating
expect VFR conditions to develop around 18Z.
EXTENDED AVIATION OUTLOOK...Early morning fog/stratus expected
to bring MVFR or lower conditions Monday. Gusty winds and
restrictions in thunderstorms expected Monday as a cold front
moves through the region. Another round of flight restrictions
is possible Wednesday night into Thursday as another cold front
crosses the region.