404
FXUS62 KGSP 091101
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
701 AM EDT Mon Mar 9 2026

.WHAT HAS CHANGED...
A Dense Fog Advisory was issued for our NC Piedmont zones until
11 AM this morning. The Special Weather Statement for patchy dense
fog was extended until 11 AM for the rest of our fcst area.

Updated the aviation discussion for the 12z TAFs.

&&

.KEY MESSAGES...
1. Areas of fog and low stratus are expected across our area this
morning. The fog could become dense and will likely linger well
into the morning. Otherwise, drier conditions are expected today
with temperatures remaining well-above normal for early March.
2. Near-record warmth returns on Tuesday and Wednesday, with
scattered showers and thunderstorms expected Tuesday.
3. A strong cold front arrives Wednesday night producing widespread
showers, isolated thunderstorms and perhaps a low end severe
weather threat. Much cooler and drier weather develops behind
the front for Thu and Fri.

&&

.DISCUSSION...
Key message 1: Areas of fog and low stratus are expected across our
area this morning. The fog could become dense and will likely linger
well into the morning. Otherwise, drier conditions are expected today
with temperatures remaining well-above normal for early March.

Light to calm winds and a moist boundary layer will create an ideal
environment for low stratus and fog to develop across our area over-
night. In general, the eastern SC Upstate and NC Piedmont still appear
more likely to see widespread dense fog, however we`re already seeing
sites in the western Upstate and NC mountain valleys with reduced vis-
ibilities. A Special Weather Statement for patchy fog has been issued
for all of our non-mtn zones. If the fog becomes more widespread, a
Dense Fog Advisory will likely be needed. With winds remaining light
and low clouds expected to linger thru most of the morning, any fog
will likely not burn off until late morning for most locations.

Otherwise, once the morning fog/stratus dissipates, temperatures will
rebound into the mid to upper 70s across the lower elevations, ending
up 15+ degrees above normal. Nonetheless, the highs will still likely
fall short of daily records at our climate sites.


Key message 2: Near-record warmth returns on Tuesday and Wednesday,
with scattered showers and thunderstorms expected Tuesday.

A split upper air pattern will be in place atop the country through
mid-week, with amplification occurring in the northern stream in
response to northwestern Conus height falls...while the southern
stream will be dominated by an upper low kicking from the Four
Corners into Texas. For Tuesday, low level trajectories originating
from the Gulf will ensure elevated moisture levels supporting at
least modest levels of instability. Scattered showers and perhaps
a storm or two may be ongoing Tue morning, as a dampening short
wave trough passes over the region within broader area of height
rises. This feature will pass east of our area by afternoon, but
additional isolated or widely scattered development is possible
during the afternoon within the unstable environment. Deep layer
shear of 30-40 kts won`t be especially conducive to organized
convection given the expected limited instability, but a stray
severe storm can`t be ruled out.

The bigger story for the mid-week period will be the return of
record, or at least near-record warmth, as heights rise and a muggy
warm sector regime becomes re-established. The current max temp
forecast for Tue is just a degree shy of daily records at KCLT and
KGSP, and would break the record at KAVL by a couple of degrees. For
Wed, the current forecast exceeds daily records at KCLT and KAVL,
and is within a degree of the record at KGSP. Record warm min temps
are also likely to be broken Tue night.


Key message 3: A strong cold front arrives Wednesday night producing
widespread showers, isolated thunderstorms and perhaps a low end
severe weather threat.  Much cooler and drier weather develops
behind the front for Thu and Fri.

A weakening upper low in the southern stream of a split flow
regime will move from Texas into the Deep South Wed night, as a
strong northern stream wave will be digging across the Great Lakes
and the Ohio Valley...with phasing of the two streams expected
over the East on Thursday. Associated strong frontal zone is
forecast to move into the forecast area between 06-12Z Thursday,
warranting likely-to-categorical PoPs across the entire area from
late Wed night through Thu morning. Strong moisture flux will
be in place off the Gulf in advance of the front, which combined
with warm/well-mixed conditions could maintain a ribbon of weak
surface-based instability immediately ahead of the front. The
Global models continue to depict a narrow zone of focused ascent
along the leading edge of the front, which could interact with the
weak instability to produce a low-topped quasi-linear convective
system. Limiting factors for an organized severe storm threat are
due to the delayed phasing of the upper air pattern...which may
not be completed until the upper trough is east of the forecast
area. This results in forcing not being as deep and strong as one
would usually like to see for low CAPE environments. Additionally,
low-level flow will be veered and large unidirectional...resulting
in 0-1km shear values of 25-30 kts...strong, but not the 35+ kts
that we typically need for anything more than a marginal threat
in weakly unstable situations. Nevertheless, the forecast pattern
and ingredients will be adequate for a low-end threat.

Strong cold advection will overspread the area during the daylight
hours Thursday, and the high elevations may see a transition
to a brief period of snow or a rain/snow mix before the precip
ends...and even some light accums are possible above 3500 feet or
so. Temperatures will return to levels more sane for late winter
Thu-Fri, but that will be short-lived as return flow sets up and
height rise over the region...downstream of more western Conus
height falls. As a result, temps quickly to well-above normal
levels over the weekend...although conditions will remain dry as
moisture will be slower to increase.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Expect dry, VFR conditions thru most of
the 12z TAF period outside of patchy dense fog and low stratus
this morning. A handful of terminals are still reporting 1/4 SM
and FG, with others reporting anywhere from MVFR to IFR. These
restrictions are likely to linger thru most of the morning as
winds will remain light to calm and it will take some time for
daytime heating to have a substantial impact. Expect all sites
to return to VFR by 14 to 15z. Otherwise, winds will be light
to calm well into the morning. Outside the mtns, they will pick
up from the WSW/SW during the afternoon with speeds between 5
and 10 kts. At KAVL, winds will remain light today and generally
favor a NWLY direction this afternoon. A PROB30 for -SHRA was
included at KCLT and the Upstate terminals for Tuesday morning/
afternoon for the shower chance.

Outlook: The spring-like weather pattern will linger for the
next few days with patchy fog/low stratus possible each morning.
Isolated TSRA may return Tues with better TSRA chances expected
Wed night into early Thurs. Gusty winds will develop Wed into
Thurs across the area as well. Drier conditions return late Thurs
into Fri.

&&

.CLIMATE...
RECORDS FOR 03-09

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      80 1974     22 1932     57 1964      8 1996
   KCLT      83 2009     30 1960     62 1925     16 1996
                1974                    1921
                1925
   KGSP      85 2009     29 1960     60 2009     16 1996
                                        1921



RECORDS FOR 03-10

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      76 1974     29 1932     58 1903     10 1996
                                                    1932
   KCLT      82 1974     36 1924     59 1903     17 1932
   KGSP      84 1974     39 1924     58 2009     17 1932
                                        1997



RECORDS FOR 03-11

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      79 1967     29 1924     55 2016     14 1934
                1925
   KCLT      83 2015     37 1960     60 1986     22 1969
                2009                                1934
                1990
   KGSP      84 2009     34 1960     60 1986     17 1969

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Dense Fog Advisory until 11 AM EDT this morning for NCZ035>037-
     056-057-068>072-082-502-504-506-508-510.
SC...None.

&&

$$

JDL/JPT