Area Forecast Discussion Issued by NWS Columbia, SC
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KCAE 180845
AFDCAE
Area Forecast Discussion
National Weather Service Columbia SC
445 AM EDT Wed May 18 2022
.SYNOPSIS...
-- Changed Discussion --
Warming trend through the end of the week with temperatures well
above average. Isolated thunderstorms Thursday, mainly in the
northern Midlands. Better rain chances return this weekend with
chance of mainly diurnal thunderstorms and showers.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Mostly clear skies this morning with high pressure continuing to
build in from the west. Decent radiational cooling has taken place
with temperatures dropping into the upper 50s so far. Ultimately the
lack of wind will allow for temperatures to drop a few more degrees,
ending up in the mid to upper 50s before the sun rises.
Flat ridging overhead today combined with WAA in the lower levels
will allow temperatures to reach the low 90s across much of the
area, possibly mid 90s in the CSRA. Skies will be mostly clear
except for some flat cu which may pop up this afternoon in response
to daytime heating. Shortwave energy will push through the Ohio
Valley this evening, with the southernmost extent approaching our
area from the northwest. Expect some increasing clouds late tonight
particularly across the northern Midlands in association with
this feature, but any precip potential should hold off until
later in the day on Thursday. Windspeeds also remain in play
tonight, and so ideal cooling is not expected to take place.
Overnight low temperatures tonight will be in the mid to upper
60s.-- End Changed Discussion --
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
-- Changed Discussion --
The trough will dig into the eastern US on Thursday with the main
surface low moving into New York and Pennsylvania that morning. The
warm front associated with it will remain well north of our area,
which should focus convection further up the East Coast. Lack of
moisture and significant forcing will be a limiting factor in any
thunderstorm development. Given the high instability, high lapse
rates aloft, and deep shear, any storms that do develop will bring
strong, possibly damaging winds. CAMs are beginning to show more
activity in the Carolinas and within our CWA much of it appears to
focus mainly the northern Midlands. Timing of the stronger
convection looks to be late afternoon, possibly into the evening as
a weak shortwave moves along the boundary. SPC indicates a Marginal
Risk for Thursday along the Midlands and general thunder for the
CSRA. Temperatures will continue to be on the rise with highs in the
mid to upper 90s.
Improved ridging over the Southeast and drier Friday with PWAT
values around an inch. Southwesterly flow at the surface bringing
temperatures around ten degrees above average, the highest
temperatures since last summer. A deep closed low will be moving out
of the Rockies in the morning and quickly head up southeast Canada
overnight. As the upper level trough digs into the Midwest moisture
advection will increase over the area although we will remain dry at
the surface. Temperatures in the upper 90s with lows around 70.-- End Changed Discussion --
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
-- Changed Discussion --
Forecast remains relatively unchanged as models continue to be in
good agreement. A deep trough will begin to dig into the far east
Rockies Saturday and move into the Great Plains Sunday morning. With
high pressure weakening and increased southerly flow, moisture will
move in from the Gulf and allow for rain and thunderstorm chances
for much of the weekend. Precip will favor the afternoon hours but
along with some diurnal thunderstorms a few weaker shortwaves will
move across the area ahead of a cold front. Lack of dynamic forcing
will keep precip coverage scattered to widely scattered. The front
will stall late Sunday, ensuring rain chances stick around into the
beginning of next week. Temperatures will be closer to normal by
Monday in the mid to upper 80s.-- End Changed Discussion --
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
VFR conditions expected.
Mainly SKC except for a FEW passing thin, high clouds with light and
variable SFC winds at all TAF sites. Widespread fog is not expected
to be an issue with deep dry air in place, but there is low
confidence in some brief VSBY reductions are possible at OGB.
Southerly winds will develop late this morning through the afternoon
at 6-10 kts with a typical scattered cu field around 5k-8k ft MSL.
Thicker clouds pass mainly north of the terminals late in the period
as a system nears from the northwest.
EXTENDED AVIATION OUTLOOK...VFR conditions expected through the
week outside of any showers Thursday-Saturday.-- End Changed Discussion --
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$