Fort Mill, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

357
FXUS62 KGSP 070608
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
108 AM EST Sat Mar 7 2026

.WHAT HAS CHANGED...
There is a marginal risk for severe storms this evening into the
early part of the overnight...mainly for the NW half of the
forecast area.

A consensus of the latest convection-allowing models depict minimal
coverage of showers/storms during the daylight hours Sunday. The
current likely PoPs in the official forecast may need to be paired
back in later updates.

&&

.KEY MESSAGES...
1. A line of thunderstorms may organize over Tennessee Saturday
afternoon and reach the mountains of North Carolina before
weakening late Saturday evening. There is a Marginal Risk of
severe thunderstorms over the mountains and foothills through
Saturday night, with the main threat being damaging wind gusts.
2. Warm and well above normal with mainly diurnal convection each
day through the middle of next week. The potential for organized
convection increases Thursday into Friday in association with a
cold front, with cooler weather following.

&&

.DISCUSSION...
Key message 1: A line of thunderstorms may organize over Tennessee
Saturday afternoon and reach the mountains of North Carolina
before weakening late Saturday evening. There is a Marginal Risk
of severe thunderstorms over the mountains and foothills through
Saturday night, with the main threat being damaging wind gusts.

Our recent late-spring-like pattern will relent somewhat over the
next 24 hours, to the extent that the upper anticylone/sfc high off
the Southeast Coast flattens and moves east, but in the meantime a
S/SW low level flow ahead of an approaching front will continue to
bring warmth and humidity into the region. The balance of Saturday
is expected to be not as eventful as Friday. Lingering cloudiness
in the morning should prevent temps from warming up quite so fast,
thus the record highs are not as likely to be broken. We should
also get a later start toward convective initiation, so precip
chances are pushed out more into the late afternoon.

The main concern will be storms that develop along/ahead of the
approaching cold front in the afternoon out over TN. The CAMs
suggest a line of storms that would organize over middle TN in the
late afternoon and then plow eastward toward the mtns in the evening
before the front slows down as the pattern becomes more zonal. The
environment ahead of the front/convective line looks rather modest
with muCAPE no better than maybe 1000-1500 J/kg and shear on the
order of 25-30 kt. This, being a somewhat limiting factor, is what
is probably keeping the convective outlook set at a Marginal Risk
for the area basically N and W of I-85 thru daybreak Sunday. Still,
the output of the 00Z HRRR and NAMNest look interesting enough to
support the idea that there would be some wind gust potential with
the storms as they reach the mtns Saturday evening. The convective
environment looks more unfavorable east of the mtns early Sunday
morning. As to the forecast, the precip probs ramp up to the
likely and categorical ranges over the mtns Saturday evening,
but will stay more in the chance range over the east. Note that if
the available 00Z CAMs are correct, the remnants of the convective
line will be passing off to the east by daybreak Sunday, and thus
the precip probs seen in the model blend at 12Z Sunday would be
way overdone. Don`t be surprised to see some downward adjustment
later today.


Key message 2: Warm and well above normal with mainly diurnal
convection each day through the middle of next week. The potential
for organized convection increases Thursday into Friday in
association with a cold front, with cooler weather following.

With a region of dampening height falls passing north of the
area...a weak cold front is expected to be draped across the
forecast early Sunday. The latest Convection-Allowing Models
suggests showers and storms will be few and far between early
in the day, but coverage should blossom throughout the late
morning into the afternoon as the boundary layer warms/modestly
destabilizes. Morning cloud cover is expected to limit the degree of
instability to the tune of 500-1000 J/kg, but improved deep layer
shear of 30 to 40 kts will increase the potential for organized
convective structures. Nevertheless, the shear/buoyancy combo will
support a marginal-at-most risk of severe storms.

Frontal boundary will push east of the area by late Sunday,
generally bringing an end to convective chances. Having said that,
any air mass change will be subtle (a slight drop in dewpoints),
with upstream height falls flattening the upper air pattern over the
northern half of the country, while a strong upper low is expected
to settle over the Baja. A warm and humid warm sector regime will
return to our area by Tue, with mostly diurnal convective chances
returning through mid-week. Daily high temp and maximum low temp
records will be in jeopardy each day Mon->Wed.

Toward mid-week, an area of height falls making landfall in the
Pacific NW is forecast to kick out the Baja upper low over the
Four Corners, with phasing of the northern and southern stream
into an anomalously deep trough likely occurring across the Great
Plains and Miss Valley by Wed night. Associated cold front will
likely march across the Southeast and Mid-Atlantic Wed night into
Thu. A consensus of model guidance indicates the potential for a
well-forced front interacting with an unseasonably warm and humid
air mass, and thus at least some potential for organized/perhaps
severe convection and locally heavy rainfall. Forecast temperatures
finally return to values more sane for the first half of March
Thu into Fri.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: Once again we look to the south for the
development of a low cloud deck and/or fog that may move into
our area with the continuing light SLY flow. The boundary layer
should be moist enough that the development of a cig restriction
by mid-morning is a decent bet as convection starts to bubble
up with some heating. By mid-afternoon the boundary layer should
deepen enough to lift the ceiling to VFR, if it hasn`t already
scattered out. The S to SW flow will continue with some gusts
possible in the afternoon. Guidance suggests a better chance of
shower/thunderstorm activity this evening into the overnight as
a front approaches from the west. Thus, I have PROB30s for -TSRA
at all sites during this time window with prevailing showers and/
or thunderstorms at most terminals just after 00z.

Outlook: The spring-like weather pattern will continue for the next
several days with patchy fog/low stratus possible each morning.

&&

.CLIMATE...

RECORDS FOR 03-07

  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      82 1974     23 1920     61 1956     15 1960
   KCLT      85 1974     30 1899     63 2022     14 1899
                                        1956
   KGSP      83 1974     36 1920     62 1961     13 1901
                            1901        1956



RECORDS FOR 03-08

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      81 1974     23 1996     57 1921      8 1920
   KCLT      84 1974     36 1989     59 1946     16 1920
   KGSP      84 1974     35 1899     56 1921     14 1901
                                                    1899



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...None.
SC...None.

&&

$$

JDL/JPT/PM