Greenville, North Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

214
FXUS62 KMHX 171040
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
640 AM EDT Fri Jul 17 2026

.WHAT HAS CHANGED...
Updated Aviation Disco.

Previous AFD...
Heat Advisory has been issued for the majority
of the FA.

SPC continues a Marginal Risk (lvl 1 of 5) of severe
thunderstorms for a portion of the area on Saturday.

SPC has expanded their Slight Risk (lvl 2 of 5) of severe
thunderstorms to cover more of the FA for Sunday.

&&

.KEY MESSAGES...
1) Building heat and humidity through the weekend.

2) Unsettled pattern expected to return this weekend into next
week, including a risk of strong to marginally severe thunderstorms
and heavy rainfall.

&&

.DISCUSSION...
KEY MESSAGE 1...While a warming trend is still expected through
this weekend, elevated smoke from Canadian wildfires continues
to complicate the temperature forecast. Available smoke guidance
suggests this smoke layer mainly over Virginia, will sink south
into North Carolina on Friday. In fact, some guidance suggests
the layer of smoke may lower closer to the surface and lead to
some reductions to visibility, especially across northern
portions of Eastern NC, along HWY 64. Yesterday we saw a sharp
gradient in temperatures for areas underneath the smoke compared
to areas with full sunshine. It appears that gradient will be
over ENC today, with temperatures most impacted across Virginia.
If the smoke does, indeed, fill back in from the north on
today, then temperatures would likely be impacted. Last few
synoptic runtimes of the HRRR keep the densest smoke just N of
the FA, though there will be some evidence of the across the
northern areas mentioned above.

The uncertainties with temperatures also complicated the
decision to issue heat headlines or not. The potential impact
from smoke plus afternoon mixing out of lower dewpoints could be
enough of a limiting factor to keep the risk of 105+ heat
indices lower today. If the smoke ends up having less of an
impact as the HRRR suggests, then heat indices would likely be
higher. Moistening southerly flow should lead to higher
dewpoints today. Even with somewhat muted afternoon heating, the
temp/dewpoint combo appears more supportive of heat headlines
compared to yesterday. Have gone slightly below NBM with a HiRes
blend for temperatures inland as RTMA shows that NBM was a tad
too warm THU, though performed well with Tds. NBM/CONSMOS blend
for OBX. Current forecast calls for MaxAppT values in the
105-109deg range for most of the area, with areas near the
Crystal Coast possibly exceeding 110deg briefly before the
afternoon seabreeze pushes through. Because of this, have
issued a Heat Advisory for all zones except for NOBX where
MaxAppT are forecast to reach triple digits, but remain below
criteria for any headlines.

KEY MESSAGE 2...There are several factors expected to support
an increasingly active pattern from the weekend into next week,
but also with some important considerations.

Upper level troughing is forecast to develop across the Eastern
U.S. with ridging shifting away from the area. The lack of
subsidence, alone, can help support a more active pattern.
Additionally, persistent southerly flow east of the trough,
potentially with a subtropical connection, should act to enhance
low-mid level moisture across the area. Meanwhile, heating of a
moistening boundary layer should lead to sufficient instability
and reduced inhibition in support of periods of convection.
Today, showers and tstorms re-enter the forecast increasing
moisture convergence ahead of a front approaching from the N
this afternoon may get enough of a initiating force from the
seabreeze to warrant SChc-Chc PoPs this afternoon into this
evening.

At the surface, the front approaching the area this afternoon
will lift back Nward into VA tonight, acting to "warm-setor"
the entire FA for the weekend. Lee- side troughing and,
eventually, a frontal boundary that will reach the FA by MON
should provide areas of enhanced low- level forcing this
weekend. SPC has portions of the FA outlined in a Marginal Risk
(lvl 1/5) of severe thunderstorms SAT. This threat for day 2
mostly encompasses the potential for stronger storms that
develop W and N of the FA in the afternoon reaching NWernmost
zones after sunset SAT. SPC day 3 outlook for SUN features a
Slight Risk (lvl 2/5) for a portion of the FA, and a Marginal
Risk (lvl 1/5) for the remainder of the area. Moisture pooling
and low level convergence will be maximized SUN afternoon into
SUN night as the cold front approaches. PWATs peak on the order
of 2 and 3/4in with increasing afternoon and evening instability
through the weekend. Additionally, while guidance remains
mixed, there is a modest signal for low pressure development
across the northeastern Gulf. Whether this obtains tropical
characteristics or not, it could act to enhance rainfall along
the Southeast U.S. coast if it ends up getting pulled north
ahead of the above-mentioned upper trough. Not all guidance show
this though, as some ensemble members take the low west across
the northern Gulf Coast. The National Hurricane Center has
maintained a 20% probability of development over the next 7
days, and it is something we will be monitoring through the
weekend and into next week.

Tropics aside, deterministic and machine learning guidance
continue to show a good signal for some strong to marginally
severe thunderstorm potential during this period of active
weather. Right now the signal is the strongest on Sunday. Given
increased forcing from the approaching front and the potential
tap of subtropical moisture, heavy rain and some hydro impacts
may eventually be realized.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
Predominant VFR flight cats are expected to prevail through the
period, though some patchy fog lingers this morning. There
remains an elevated layer of smoke from Canadian wildfires that
is meandering around the region. Guidance suggests this should
remain elevated and not impact visibilities today. Winds will
be light and variable through the morning with a low end chance
decoupled sites seeing subVFR patchy fog. OAJ has dipped down to
IFR VIS but should see improved VIS after sunrise, so have
carried a tempo MVFR group for one hr at the 12Z TAF time. FRI
afternoon sees a return of showers and tstorms development
potential along the seabreeze. Not high enough PoPs to warrant
any subVFR mention explicitly in the TAFs, but have included
VCSH wording in the afternoon into the evening for all
terminals. With the 12z update, have added a couple hr prob30
group for OAJ with PoPs in the upper 20%s for a few hours.

Outlook (Friday night through Tuesday): Guidance suggests smoke
from Canadian wildfires may try to work down to the surface
Friday night with reductions to VIS possible. It`s unclear
whether or not smoke impacts will last into the weekend.
Otherwise, the risk of TSRA is expected to slowly increase
Saturday night, becoming more likely from Sunday into early
next week. Sub-VFR conditions can be expected along with the
TSRA impacts.

&&

.MARINE...
Latest surface and buoy obs indicate SW winds 5-10kt inside,
10-15kt outside with seas 1-3ft with SW wind waves ~2ft on top
of 1-2ft weak ESE longer period swell. A cold front approaches
from the N through the day today, lifting back into VA
sometime this evening. This will lead to a slight wind shift
over Nern waters where the winds becoming southeast or east for
several hours. Eventually, Serly flow will return for all
waters tonight behind the departing boundary.

Outlook (Friday night through Tuesday): Southwesterly winds are
seas are expected to build to 20-30kt over the weekend as the
gradient sharpens in advance of another front approaching the
region. Over the outer coastal waters, frequent gale-force gusts
appear possible for several hours Saturday night into Sunday
morning. It may not quite reach the threshold for a Gale Warning
there, but the increased winds are notable. Seas will quickly
respond to the winds, building to 4-7ft by Saturday night.
Marine headlines appear probable for coastal waters and PamSound
for this timeframe. Elevated winds and seas are expected to
last into early next week for the nearshore coastal waters. For
the outer waters, elevated winds and seas may last for much of
the week.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Heat Advisory from 11 AM this morning to 8 PM EDT this evening
     for NCZ029-044>047-079>081-090>092-094-193>196-198-199-
     204-205.
MARINE...None.

&&

$$

DISCUSSION...CQD/CEB
AVIATION...CQD/CEB
MARINE...CQD/CEB