Winston-Salem, North Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

658
FXUS62 KRAH 151900
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
300 PM EDT Wed Jul 15 2026

.WHAT HAS CHANGED...

* Haze added to the forecast for the next couple of days over the
  northeast Piedmont and Coastal Plain

&&

.KEY MESSAGES...
As of 300 PM Wednesday...

1) Hazy skies from Canadian wildfire smoke mainly over the northeast
Piedmont and a portion of the Coastal Plain, and otherwise hot, but
with low afternoon RH the next couple days

2) Increasing moisture will fuel potentially hazardous heat Fri and
Sat as well as isolated diurnal convection until an effective front
brings more appreciable chances for storms on Sun.

&&

.DISCUSSION...
As of 300 PM Wednesday...

KEY MESSAGE 1... Hazy skies from Canadian wildfire smoke mainly over
the northeast Piedmont and a portion of the Coastal Plain, and
otherwise hot, but with low afternoon RH the next couple days

Wildfire smoke originating in srn ON and nrn MN will manifest as
continued hazy skies and apparent high-level ceilings mainly over
the ne Piedmont and a portion of the Coastal Plain for the next
couple of days. Aside from a minimal restriction to visibility (eg.
7-9SM) around the Richmond Metro and Hampton Roads, there have been
no observed visibility restrictions from the portion of the smoke
plume now maximized over nern NC and the Virginias. Given these
observational trends and also HRRR and RRFS simulations of near-
surface smoke, no appreciable restrictions to surface visibility are
expected at the latitude of cntl NC at this time.

It will otherwise turn hotter, though perhaps tempered slightly by
wildfire smoke, as a mid-level ridge centered over the OH Valley
progresses across and offshore the srn Middle Atlantic, while
weakening. Related subsidence and adiabatic warming will add another
few degrees C to the observed 850 mb temperature of 19C at GSO this
morning. That warming would translate to high temperatures in the
upper 90s to around 100 F, assuming no appreciable impact from
wildfire smoke to insolation/diabatic heating. Based on surface
observational trends this afternoon beneath the aforementioned
densest portion of the smoke plume now over VA and nern NC, there
may be a couple of degree impact to surface temperatures over the ne
Piedmont and a portion of the Coastal Plain on Thu.

Both the 12Z-observed soundings at GSO and MHX also sampled a layer
of markedly dry air between 900-800 mb, with dewpoint depressions of
30-40C, atop a shallow, surface moist layer and with related mean
mixing ratios of 10-11 g/kg. Surface dewpoints today have
consequently "mixed out" through the 60s, with some 50s F noted over
the Piedmont; and this process will result again on Thu, though with
surface dewpoints probably a few degrees higher owing to a slight
uptick in forecast mean mixing ratios.

As such, heat index values should be tempered on Thu and remain
mostly in the 100-105 F range and shy of Advisory criteria of 105 F
or greater for two consecutive hours.


KEY MESSAGE 2... Increasing moisture will fuel potentially hazardous
heat Fri and Sat as well as isolated diurnal convection until an
effective front brings more appreciable chances for storms on Sun.

The mid-level ridge and area of associated subsidence from the Ohio
Valley into the Carolinas begins to break down late this week and
will provide an opportunity for increasing surface moisture with
upper 60s to around 70 dew points during peak heating Fri and Sat.
Convective coverage may remain isolated at best until the late
afternoon/evening hours as the upper-lvl anticyclone remains
positioned over the Ohio Valley on Fri and over the Carolinas on
Sat. If surface moisture is able to remain elevated with limited dry
air aloft to tap into during diurnal heating, air temperatures in
the upper 90s to around 100 would support heat indices in the 105-
109 range for consecutive hours, primarily across the eastern
Piedmont, Sandhills and Coastal Plain. Although some acclimation is
most likely beginning to set in, individuals especially sensitive to
the heat as well as anyone partaking in strenuous activity during
peak heating will be susceptible to heat related illness if
precautions are not taken.

Our perhaps better chance for more scattered to locally numerous
showers/storms comes Sat night into Sun. A shortwave trough
progressing through Ontario and trailing trough axis sliding across
the Mid-Atlantic into the Carolinas will likely provide weak
synoptic forcing along with any embedded convective perturbations to
drive precipitation chances. Most likely 24 hour rainfall totals
range from minor amounts to around 0.75" through Mon morning
(greatest in the east). However, model guidance is hinting at
lingering surface high pressure over the northwestern Gulf as well
as an area of low pressure that may develop tropical characteristics
in the northeastern Gulf during this time. Both of these features
may prevent Gulf moisture from lifting through the Southeast and
into the Carolinas, which could limit rainfall amounts in magnitude
and aerial coverage.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
As of 140 PM Wednesday...

Dry air influence, from both a surface ridge over NC and a mid/up-
level one over the OH Valley, will favor VFR conditions in cntl NC
through the 24-hour TAF period. Wildfire smoke originating in srn ON
and nrn MN will manifest as continued hazy skies and apparent high-
level ceilings mainly from RDU and RWI and points newd for the next
couple of days. No restrictions to surface visibility are expected
at the latitude of cntl NC at this time.

Outlook: Increasing low-level moisture/humidity levels this weekend
will support a chance of stratus/mist/fog and showers/storms, with
the latter favored on Sun.

&&

.CLIMATE...

Record temperatures within 3F of forecast ones...

Record Highs:

July 16: KGSO: 99/1915 KRDU: 101/1887

July 17: KRDU: 100/1887 KFAY: 102/1932


Record High Mins:

July 17: KGSO: 75/2025 KFAY: 77/2019

July 18: KGSO: 76/1986 KFAY: 77/2025

July 19: KGSO: 75/2016 KFAY: 77/2023

July 20: KRDU: 76/2025

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...MWS/AS
AVIATION...MWS
CLIMATE...data/local