Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 292140
Area Forecast Discussion
National Weather Service Columbia SC
540 PM EDT FRI JUL 29 2016
Upper level ridge off the southeast coast allowing an increase in
moisture for the weekend. Chances of thunderstorms will increase
through the weekend. Temperatures will lower a few degrees...however
afternoon high temperatures will remain in the mid to upper 90s
through early next week.
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Weak to moderate instability combined with some shortwave energy has
caused a few showers and isolated storms to form across the
Midlands and Pee Dee. Activity is not very deep, and expect mainly
a brief passing shower with the precip. Will continue with
isolated showers/storms through midnight. Winds not as strong late
tonight. Low temperatures tonight will be in the mid to upper
70s once again.
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
Upper level trough stretching through the OH and MS valley region
will slowly shift eastward through the weekend providing a better
chance for storms than in recent days. Lee side troughing will
continue while a frontal boundary remains across the Mid-Atlantic
states, well north of the forecast area. Abundant moisture will be
across the area both Saturday and Sunday with precipitable water
values generally around 1.8 to 2.0 inches. The 12Z NAM shows weak
instability on Saturday but stronger instability on Sunday. The
biggest threats with strong storms would be damaging winds and
small hail. High temperatures are forecast above normal both days,
in the upper 90s. Heat index values will generally be around 105
.LONG TERM /MONDAY THROUGH FRIDAY/...
The GFS and ECMWF are in relatively good agreement showing an
upper level trough over the eastern US on Monday with shortwave
energy circulating through it. The trough axis slips off the
coast on Tuesday as an upper ridge builds over the center of the
country. The ridge slowly shifts east through the end of the
period. A frontal boundary is forecast to be near the NC/SC border
on Monday and may be a focus for storm activity. The deepest
moisture is forecast to be in the eastern portion of the area for
Monday. Drier air will move into the area from the north for
Tuesday so have lowered pops north. Generally expect diurnally
driven isolated/scattered convection Wednesday and Thursday as the
upper ridge expands east. Above normal high temperatures are
forecast throughout the long term with values generally in the mid
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
Outside of isolated thunderstorms...high confidence in VFR
conditions through the 24 hour TAF period.
Upper level ridge to linger off the southeast coast with a trough
crossing the MS river valley into the TN valley. Increased moisture
and convergence along a surface trough will allow for isolated
convection through this evening. Low threat for thunderstorms to
impact terminals. Scattered cumulus clouds forecast this afternoon
with bases at or above 5000 feet. Westerly winds 10 to 15 knots with
gusts around 20 knots this afternoon. Winds diminishing to light
after 30/00z. Scattered convection to develop Saturday afternoon.
The chance for thunderstorms to affect any one of the terminals is
too low to include at this time.
EXTENDED AVIATION OUTLOOK...Low potential for restrictions in
afternoon and evening convection each day.