Greenville, North Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

991
FXUS62 KMHX 271947
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
347 PM EDT Mon Jul 27 2026

.WHAT HAS CHANGED...
Tuesday night severe event has trended to a low/medium
confidence, high impact scenario.

Small Craft Advisories issued from Cape Hatteras to Surf City

Aviation section updated for 18Z TAFs

&&

.KEY MESSAGES...
1) A scattered showers/tstorms with a few stronger storms
bringing heavy rainfall rates and gusty winds until sunset.

2) Notable weather system to move through the Carolinas tomorrow with
the return of heat/humidity ahead of it and a risk of strong to
severe thunderstorms along it

&&

.DISCUSSION...
KEY MESSAGE 1...Daytime heating has brought MLCAPE values of
1000-2000 J/kg to much of the region, with further destabilization
expected as we get later into the afternoon. A stubborn dry
layer above 700mb continues along and south of 70 with slightly
more moist profiles north of hwy 70. As a shortwave sits
overhead, scattered to numerous showers are occuring north of
hwy 70 where there is more moisture to play with, decreasing in
coverage and intensity south with the drier air aloft.
Meanwhile, sea breeze moves through today. The interaction
between convection to the north and sea breeze could allow
showers and tstorms to migrate south closer to hwy 70 in the
late afternoon/early evening hours, but expect this convection
to be more transient and tame in comparison.

Overall, convective threats for today are localized flash
flooding where heavy rain rates persist over already saturated
soils, and gust winds 30-50mph as DCAPE values near 1000 J/kg
result in some downbursts. Lack of robust updraft development
precludes any meaningful severe threat today.

As we approach sunset, any lingering convection should quickly
taper off with a loss of daytime heating and the shortwave
moving offshore.

KEY MESSAGE 2...An anomalously strong upper level trough is
forecast to develop over the Mid-Atlantic Region on Tuesday,
with a potent shortwave diving southeast through Virginia and
the Carolinas Tuesday into Tuesday night. A strong LLJ ahead of
this feature should lead to increasing moisture advection, with
PWATs once again climbing back above 2". Meanwhile, heating of a
moist boundary layer should support moderate instability, with
MLCAPE rising into the 1000-1500j/kg range. Aloft, a notable
upper jet max is forecast to overspread the instability axis,
supporting deep layer shear of 30-45kt. While instability will
be moderate, the shear/instability combo is notable for this
time of year.

Synoptically, the combination of all of the factors above
checks several boxes for severe weather potential. This also
has modest support from ensemble, analog, and machine learning
guidance. With the 12Z model suite, some uncertainty has
presented itself regarding tstorm coverage. The main potential
limiting factors are timing and potential subsidence. Some
guidance suggests convection may not reach ENC until after
sunset. Despite the potential for a gradually stabilizing
boundary layer, if strong large-scale forcing is realized, it
should help support deep convection well past the typical
diurnal max in convective intensity this time of year. Given the
potential amount of forcing present, it appears likely that an
MCS will move through the eastern Carolinas and VA during the
evening and early overnight hours posing a risk of damaging
winds. Low- level SRH around 100-200m2/s2 may support a few
rotating updrafts capable of hail and tornados. However, those
latter 2 hazards should be lower compared to the wind risk.
Lastly, while a MCS would be more progressive, the high PWAT
airmass should support heavy rainfall rates which may support a
short-fused flooding risk, especially for the area hardest hit
the past few days (ie. Hyde County east through the Outer
Banks).

As alluded to earlier, with the most recent CAMs an drier
outcome has presented itself as a possibility. With the low
setting up shop in the northeast, it is possible the best
forcing shifts to the north with the low and drier air sets up
above 700mb suppressing convection. The 12Z RRFS, and FV3 are
two of the models that suggest this outcome. While most guidance
is still showing robust convection moving through the region,
the introduction of this possibility decreases confidence on
coverage of strong to severe storms tomorrow.

Ahead of the convection, hot and humid conditions are expected,
with heat indices rising to 100-105 degrees. This appears to be
a bit marginal for heat headlines, but is something we`ll
continue to assess in later forecasts.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Generally VFR conditions this afternoon, outside of areas of
reduced vis/cig where showers and tstorms are ongoing.
thunderstorm chances are generally located north of the Neuse
River, so TAF sites have low confidence of seeing TSRA. Of the
TAF sites, EWN, OAJ has the best shot, so a prob30 is in effect
until 00Z with this. Remainder of TAF sites have a less
favorable environment for thunder, so just stuck with VCSH
there. Convection will wane with loss of heating this evening,
with potential for patchy fog and low stratus overnight.

Outlook (Tuesday through Friday): A notably strong storm system
for this time of year is forecast to impact the area later Tue.
This system will be accompanied by gusty winds and an increased
risk of TSRA Tue evening, some potentially severe. Sub-VFR
conditions are expected to accompany the TSRA risk. The
strongest storms will be capable of 40-60kt winds and small
hail. Much drier behind the fropa for Wed into the end of the
week as high pres rebuilds.

&&

.MARINE...
latest obs show light S-SE winds 5-10 kt across the waters,
with seas 2-3 ft. Winds become more southerly tonight, with
scattered showers and thunderstorms for inland rivers. Storms
could produce gusty winds and a brief waterspout.

Tuesday, a strong frontal system approaches from the northwest.
Pinched gradient in the warm sector out ahead of this low
strengthens winds to 20-25 knots by Tuesday afternoon.

Outlook: A strong frontal system is forecast to impact the
waters Tuesday into Wednesday with building winds and seas and
an increased risk of thunderstorms. Winds of 15-30kt are
expected late Tuesday into early Wednesday morning. Seas are
forecast to peak in the 4-8ft range. Small Craft Advisories are
in effect from Surf City to Cape Hatteras out to 20nm, as
confidence is highest in this region. Expansion of SCAs may be
needed to include the Pamlico Sound and remaining nearshore
waters. In addition to the strong synoptic winds, a cluster of
thunderstorms moving through Tuesday evening and Tuesday night
will be capable of 40-50kt winds, hail, and waterspouts.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...Small Craft Advisory from 8 PM Tuesday to 8 AM EDT Wednesday
     for AMZ154.
     Small Craft Advisory from 5 PM Tuesday to 8 AM EDT Wednesday
     for AMZ156-158.

&&

$$

DISCUSSION...CQD/RJ
AVIATION...RJ
MARINE...RJ