Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 172342
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
642 PM EST Wed Jan 17 2018

.SYNOPSIS...
Snowfall will taper off today. In the wake of a cold front, high
pressure will overspread the region tonight and tomorrow and drift
offshore by early Saturday. Another cold front is expected to
approach the Carolinas early next week.

&&

.NEAR TERM /THROUGH THURSDAY/...
As of 640 PM EST: Latest radar shows snow showers quickly
diminishing and moving east of the area as deformation zone around
the upper low moves east. Do not expect any additional significant
accumulations. Sat pix show the back edge of the clouds following a
similar pattern. Expect clearing to develop through the evening,
except for some lingering upslope NW flow clouds across the
mountains. Therefore, have expanded the Winter Weather Advisory for
black ice to cover the counties covered by the expiring Warning.
Cold and windy conditions already in place across the NC Mountains.
In fact, latest guidance suggests that wind chill values will drop
below -5 across much of the French Broad Valley overnight.
Therefore, have expanded the Wind Chill Advisory to cover all
elevations of Madison, Buncombe, and Henderson Counties. The
advisory still looks well placed for the rest of the area. Lows in
the teens to single digits still expected.

Sunny conditions tomorrow should yield plenty of melting, while
temps should warm up significantly, although any warming trend will
be tempered by snowpack in many areas. Thus, max temps will be a
solid 10-15 degrees below climo in most areas.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
As of 230 PM EST Wednesday: The short term fcst period continues to
look rather quiet as very weak upper trofing across the plains
allows for weak, yet improving llv warm advection.  High pressure
located along the gulf coast will promote swly flow at the surface,
thereby supporting an overall warming trend.  Temperatures at fcst
onset Thursday evening could be a bit tricky depending on the degree
of warming and any residual snowpack from today`s event, thus will
probably lean a bit cool with respect to guidance for overnight
temperatures.  Moving on into Friday, southerly waa will prevail
leading to temperatures returning closer to normal, warming further
to above normal on Saturday amidst mostly sunny skies.  All in all,
moderating temperatures amidst melting snow pack and otherwise dry
conditions to highlight the short term.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 200 PM: A surface ridge is currently expected to remain over
the Southeast states Sunday and early Monday. Aloft, a partially
cut-off upper low is progged to drift through, though operational
models and ensemble members suggest it will be too far south to
affect us with sensible weather. Dry and warm conditions thus are
expected early in the medium range period. However, at the same
time, a potent upper trough and deepening sfc low will affect the
northern Plains. The cold front associated with this system will
move across the lower Mississippi Valley on Monday, most likely
crossing our CWFA Monday night. At the present time it appears
there is little severe wx threat due to a lack of instability
(even GEFS probability of 250 J/kg CAPE is below 10 percent). This
is at least partially attributable to the nocturnal timing, which
could change. This trend will be something to watch over the next
few days. Otherwise, above-normal temps are expected prior to the
fropa, with seasonably cooler conditions developing behind it. At
least a small chance of rain changing over to snow exists for the
mountains on the back side of the front.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
At KCLT: A brief light snow shower and MVFR cigs may move across the
airfield early this evening before the back edge of the precip and
clouds move east of the area. Expect low VFR to scatter out by
midnight with generally clear skies through the rest of the period.
Gusty N wind slowly diminishes this evening. WSW wind develops near
daybreak then turns WSW for the afternoon. Very cold temperatures
tonight will result in any melt water refreezing.

Elsewhere: Snow showers quickly coming to an end with skies clearing
as the back edge of precip and clouds move east of the area. Any
lingering low VFR clears out by midnight. N wind slowly diminishes
this evening turning WNW by daybreak. Winds turn WSW for the
afternoon. Very cold temperatures tonight will result in any melt
water refreezing.

Outlook: Dry/VFR condition are expected to continue through the
week and into the weekend.

Confidence Table...

            23-05Z        05-11Z        11-17Z        17-18Z
KCLT       High  89%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High 100%     High 100%     High 100%
KHKY       High 100%     High 100%     High 100%     High 100%
KGMU       High 100%     High 100%     High 100%     High 100%
KAND       High 100%     High 100%     High 100%     High 100%

The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:

www.weather.gov/gsp/aviation

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Winter Weather Advisory until 11 AM EST Thursday for GAZ010-
     017-018-026-028-029.
NC...Winter Weather Advisory until 11 AM EST Thursday for NCZ033-
     035>037-048>053-056>059-062>065-068>072-082-501>510.
     Wind Chill Advisory until 7 AM EST Thursday for NCZ048-051>053-
     058-059-062>065.
     Wind Chill Advisory until 10 AM EST Thursday for NCZ033-049-
     050.
SC...Winter Weather Advisory until 11 AM EST Thursday for
     SCZ001>014-019.

&&

$$
SYNOPSIS...Wimberley
NEAR TERM...JDL/RWH
SHORT TERM...CDG
LONG TERM...Wimberley
AVIATION...RWH



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