Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 180831
Area Forecast Discussion
National Weather Service Columbia SC
331 AM EST Wed Jan 18 2017
A weak cold front in the forecast area today will be south of the
area tonight. Ridging will extend through the region in the wake of
the front tonight and Thursday. A warm front will be in the area
Thursday night and Friday.
.NEAR TERM /THROUGH TONIGHT/...
Convergence associated with the weak cold front may support
showers today, but the chance should remain low because of h85
westerly flow and significant upper lift staying well northeast
of the forecast area with the main shortwave trough moving off
the Delmarva coast this afternoon. Radar trends and the high-
resolution models indicate isolated coverage at most. We will
get off to a warm start because of mixing ahead of the front and
this favors the higher high temperature guidance today. Expect
near-record high temperatures for the date.
Believe wind will remain just below lake wind advisory criteria
today. The main low-level jet associated with the front will occur
early today and before greater diurnal mixing. However, it should
still be breezy. The GFS LAMP and NAM Bufkit momentum transfer tool
supports gusts 18 to 20 knots.
The front should be diffuse and south of the forecast area tonight
with 500 mb ridging moving into the area. Expect just high
cloudiness spilling over the ridge mainly late. Followed the
guidance consensus for the temperature forecast. Nocturnal cooling
and light wind may help support fog but believe the chance too low
to include in the forecast. The NAM and GFS MOS keep a significant
temperature and dew point temperature spread and expect more upper
cloudiness late as the ridge axis shifts east.
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
The models show the surface ridge extending through the
forecast area Thursday with the ridge off the coast Thursday
night. Moisture is displayed becoming deep Thursday night
associated with a warm front and mid-level shortwave trough. The
front may linger Friday, but moisture should become shallow
behind the mid-level feature. The guidance consensus supports
pops categorical Thursday night and chance Friday. The NAM has
cross totals in the middle 20s associated with the mid-level
shortwave trough supporting possible thunderstorms. Believe any
thunderstorms will remain elevated as supported by the NAM and
GFS which keep surface-based LI values above zero through
Thursday night. The GFS depicts weak surface-based instability
Friday, but with just shallow moisture in the wake of the upper
feature the thunderstorm chance should be low. Followed the
guidance consensus for the temperature forecast Thursday through
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Moisture should increase Friday night and especially Saturday
associated with a warm front. The area will likely be in the
warm sector ahead of a strong cold front Sunday. The GFS and
ECMWF show the cold front in the forecast area Sunday night. The
models depict a 40- to 50-knot h85 jet associated with the
front. The high shear and instability of the warm sector support
possible severe thunderstorms. A limiting factor may be
convection near the Gulf Coast limiting the transport of
moisture and instability northward and into the forecast area.
Instability and wrap-around moisture associated with the
associated upper low support a chance of showers Monday. Drying
may occur Tuesday with the system lifting northeastward. The GFS
and ECMWF MOS plus GFS ensemble mean were most consistent with
highest pops Sunday and Sunday night. There was also consistency
with very low pops Tuesday. The GFS and ECMWF MOS have above
normal temperatures through the medium-range period.
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
Models indicating a return of restrictions 10Z-15Z. MVFR
visibilities and IFR/LIFR ceilings possible by daybreak at all sites
as a weak cold front approaches from the west. Conditions should
improve to VFR 15Z-17Z as the front moves through the area and
downslope westerly flow overspreads the TAF sites.
Isolated light rain showers possible along and just ahead of the
front...but probability too low to include in TAFs. Winds will
increase out of the west during the day Wednesday, with gusts around
20 knots from mid-morning through late afternoon.
EXTENDED AVIATION OUTLOOK...Late night/early morning fog possible
through Sunday. Showers and associated restrictions possible
Thursday night through Sunday.
The record high temperature at Columbia for January 18th
is 77 last set in 1952. The record for the date at Augusta
is 80 set in 1928.