Area Forecast Discussion
Issued by NWS Greer, SC
Issued by NWS Greer, SC
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
663
FXUS62 KGSP 060625
AFDGSP
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
125 AM EST Tue Jan 6 2026
.SYNOPSIS...
Temperatures remain well above normal through the rest of the work
week. Rain is likely for much of the area Friday night and Saturday
with a cold front. Normal January temperatures return Sunday and
Monday behind the front.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 1121 PM Monday:
Key Message #1: Patchy dense fog overnight will give way to partly
cloudy skies with warmer temperatures today and perhaps a stray
shower over the mountains.
A flat upper trough will slide from the Midwest across the Ohio
Valley today with an attendant surface low shifting across the Great
Lakes. This will drag a surface cold front into the Ohio Valley, but
the weak boundary will struggle to make significant eastward
progression. The first item to address will be the potential for
patchy dense fog overnight. Several dense fog observations have come
in and the ongoing special weather statement remains well placed.
Low stratus is also increasing in coverage as high cirrus streams
across the region. Confidence is greater coverage of dense fog is
modest at best as the increasing low clouds may inhibit further
development. The only caveat being if a stratus build down event is
able to get get going. Will thus hold off on any dense fog
advisories for now, but one cannot be completely ruled out should
trends warrant. Otherwise, fog should mix out fairly quickly after
sunrise with a return to partly cloudy skies. Warming 850mb
temperatures and rising heights will support warmer afternoon highs
in the low to mid 60s. A stray warm advection shower or two may
develop across the southwest mountains ahead of the Ohio Valley
front, but this will be the exception and not the rule. Another
largely quiet night is also in store heading into Wednesday morning
with the usual potential for patchy fog.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
As of 1100 PM Mon:
Key message: Exceptionally warm Wednesday with marginally low
relative humidity. Slightly cooler but still well above normal
Thursday.
Westerly 850mb flow continues thru Wed behind the weak front, with
slight CAA continuing into afternoon. Skies will be mostly sunny.
Downsloping and airmass modification will overcome the CAA and temps
surge 15 to 20 degrees above normal throughout the area, very near or
tying the record at GSP. At CLT the daily record is a high outlier
and AVL doesn`t quite make it with winds not as favorable for
downslope there. The deep dry inversion still will be overhead; if we
mix into that dewpoints could mix out enough to bring RH to near 30
percent in some of the Piedmont, a critical value for fire weather
interests. However, the strength of the inversion suggests mixing
depth will be limited. Regardless, winds look to be fairly light.
Front will stall south of the CWA Wed night with high pressure
centering over the Mid-Atlantic coast. By Thursday height rises occur
aloft as next shortwave moves into the lee of the Rockies, spurring
cyclogenesis, amplifying SW flow, and reactivating the front across
the Southeast, over the sfc high. Cloud cover will develop which will
keep temperatures a bit cooler Thursday, with maxes "only" 10 to 15
above normal. NBM PoPs with the activating front now don`t ramp up
until after 00z Fri which seems reasonable in light of shallow
moisture and forcing thru that time.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 1215 AM Tue:
Key message 1: Despite more cloud cover compared to the first half of
the week, temperatures remain considerably above normal until a cold
front passes Saturday.
Southerly 850mb LLJ ramps up Thursday night and introduces deeper
moisture over the area; 925mb flow initially is southeasterly which
suggests a very shallow layer of mechanical lift along the SE-facing
Blue Ridge Escarpment producing low clouds and light precip, which
might lock in a small in-situ CAD wedge with the position of the sfc
high, though the setup is marginal. PoPs are mainly in the
slight-chance (~20%) range in the upper Piedmont and 25-40% over the
Escarpment and mountain zones overnight. High mountain elevations
will see wind gusts to near 30 mph. Temperatures Fri morning look
close to normal daytime maxes. Some bust potential exists for maxes
Friday if CAD does form and especially if the wedge forms over a
larger area than expected, but otherwise, as incipient sfc low tracks
toward the Great Lakes, it will pull the warm front north of our CWA,
and should permit temps to warm a little further compared to Thu east
of the mountains. This time CLT is flirting with the record high.
Gusty but sub-advisory winds are possible in all areas Fri aftn.
Moisture deepens again late Fri with apparent arrival of warm
conveyor belt of the low and/or dynamic lift developing in right-rear
quad of jet streak; surface cold front doesn`t look to arrive until
late Saturday, and precip chances decrease during the day as the
moisture plume shifts east of the mountains. PoPs ramp up from west
to east late in the day Fri, peaking at 60-80% over most of the area
Fri night or Sat morning. Ensemble mean PWATs have been consistently
peaking at 2 to 2.5 SD above climo on the ECMWF around that time, and
have trended upward on the GEFS but not quite that high. Still seeing
the same signal as noted previously, in which model QPF rates
diminish east of the mountains. Probs from 2" total QPF from both
ensembles are only about 40-50% in our SW mountains, and less than
10% for most of our area south and east of the Blue Ridge. Hence not
seeing a strong signal for flood threat at this time, especially
coming out of a dry period.
Seeing slightly more CAPE on recent progs ahead of the front
Saturday; any SBCAPE likely would overlap with 30+ kt of 0-3km bulk
shear. Severe winds could result, but not yet seeing enough evidence
to warrant a HWO mention or briefing.
Key message 2: Temperatures return to near normal Sun-Mon behind the
front. Light northwest flow snow is possible in the mountains
Saturday night and Sunday.
Temps trend cooler only a few degrees on Saturday--still well above
normal--with CAA probably not beginning until late in the day. and
downsloping still a factor otherwise. PoPs diminish from afternoon
onward, though remain mentionable until the sfc fropa occurs
overnight. Gusty winds of at least 30-40 mph are likely in higher
mountain elevations. Temps cool to near normal for the mountains and
the pattern supports at least a brief period of light NW flow snow
behind the front near the TN border; accumulation appears minimal.
Max temps forecast near normal in the Piedmont Sunday but below
normal in the mountains. Overnight lows a few below normal Sunday
night under mostly clear skies. Cannot rule out more NW flow snow
Sunday night as base of shortwave passes, though model depictions
have backed off; high altitude cloud cover and near-normal temps
expected Monday.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
At KCLT and elsewhere: Another round of patchy fog and low stratus
has developed across the area this evening and will persist through
the overnight. Most terminals have already observed some degree of
fog with patchy dense fog possible, especially along the I-40
corridor (KHKY). A developing deck of low stratus my hinder further
fog development, however, which may also help to keep visibilities
in the MVFR range. How expansive this deck of stratus becomes will
dictate the fog potential. Either way, conditions should improve
fairly quickly after sunrise as winds pick up and help to mix out
the fog and scatter the low stratus. All terminals should see a
return to VFR by mid morning with VFR continuing thereafter. Wind
gusts will also be common this afternoon from the southwest.
Outlook: Expect dry, VFR conditions through much of the week.
Precipi-tation chances increase by the end of the week and linger
into the weekend.
&&
.CLIMATE...
RECORDS FOR 01-07
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 70 1913 20 2014 58 1913 -1 2014
KCLT 77 1890 24 1988 62 1998 6 2014
KGSP 71 2012 27 2014 59 1998 5 2014
1988
1912
RECORDS FOR 01-08
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 68 2019 13 1970 55 1937 -1 1970
1946
KCLT 74 1946 21 1970 61 1998 8 2015
1907 1970
1890
KGSP 72 1907 24 1970 56 1998 5 1970
1946
RECORDS FOR 01-09
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 71 1937 13 1970 55 1937 -4 1970
1930
KCLT 72 2008 25 1970 60 1946 4 1970
KGSP 74 1949 28 1970 57 1946 1 1970
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Dense Fog Advisory until 9 AM EST this morning for NCZ035>037-
056-057-068-069-502-504-506-508.
SC...None.
&&
$$
SYNOPSIS...JCW
NEAR TERM...TW
SHORT TERM...JCW
LONG TERM...JCW
AVIATION...TW
CLIMATE...JCW