Greenville, North Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

140
FXUS62 KMHX 212341
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
741 PM EDT Mon Sep 21 2026

.WHAT HAS CHANGED...
An initial round of marine headlines have been issued for
portions of the ENC waters for this week`s coastal low.
Additional headlines, both land and marine, will likely be
needed with future updates.

&&

.KEY MESSAGES...
1) Coastal low to impact ENC mid to late week with periods of
rain, scattered thunderstorms, and a risk of multiple coastal
hazards.

MARINE: Coastal low to produce hazardous winds and seas mid to
late week.

&&

.DISCUSSION...
KEY MESSAGE 1...A complex and initially disorganized surface
and upper level pattern today will begin to consolidate into a
notable East Coast coastal low mid to late-week, with impacts
being felt from the Carolinas north.

Aloft, an upper level shortwave will lift north off the
Southeast U.S. coast, supporting the development of a weak area
of low pressure along a stationary front. Meanwhile, a cold
front will continue to slowly sag south from Virginia into North
Carolina over the next couple of days. The above-mentioned weak
low is then forecast to deepen along the consolidating, and
strengthening, frontal/baroclinic zone off the East Coast.
Deepening of the low will become more rapid Thursday and Friday
as an upper low translates from the Ohio Valley to the Mid-
Atlantic Coast. The deepening will also be aided by the entrance
region of an upper jet which will reside over the Northern
Atlantic.

Confidence continue to increase regarding a sub-1000mb low
developing offshore during this time, and this is strongly
supported by deterministic, ensemble, and machine learning
guidance. Because of the blocky nature of the upper level
pattern over the Atlantic, there is some uncertainty regarding
the eventual track of the low. While confidence is high
regarding a notably deep low developing, confidence is lower
regarding the magnitude of winds which especially factors in
regarding coastal and marine impacts.

The most likely scenario at this point is for there to be an
initial round of showers and scattered thunderstorms late
tonight into Tuesday as the above-mentioned cold front moves
into the area from the north. Rain and perhaps a few
thunderstorms are then forecast to expand in coverage, and
become more widespread, Tuesday night into Wednesday night as
lift increases along the moistening frontal zone. During this
time, some guidance suggests an area of enhanced lift from the
Delmarva region south into NE NC, and this is where the highest
rainfall totals are expected. While instability will be waning
with time, rainfall totals of 2-3" appear plausible in this
area, which could support some minor hydro impacts in poor
drainage areas.

The strongest winds and greatest risk of coastal impacts is
expected Thursday into Friday, especially along the OBX.
Persistent northeasterly winds coupled with a longer fetch
across the Atlantic should support long-period swell of 10-13s
and wave heights of 8- 12ft in the surf zone for beaches from
Duck to Cape Lookout. Not only will this create dangerous surf
conditions, but this will also present a risk of beach erosion,
ocean overwash at vulnerable locations, and coastal flooding
(both soundside and oceanside). As mentioned above, the strength
and duration of the stronger winds varies some in the guidance
depending on the track of the low. Stay tuned as we continue to
refine the coastal impacts, and where coastal headlines may be
required. Coastal impacts may last beyond Friday. In addition to
the coastal impacts, guidance supports a risk of reaching Wind
Advisory criteria for portions of the OBX Thursday into Friday.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
VFR conditions in place over area terminals this evening with a
stalled frontal boundary draped from roughly FFA NW into
southern VA. Along the front, showers and thunderstorms are
ongoing but staying north of PGV. Farther north, large bank of
MVFR cigs is in place and is forecast to progress southward
through the overnight hours as the front sags through eastern NC
overnight into Tues AM. LAMP probabilities show up to a 60-70%
of IFR cigs especially after 06z, with a risk of LIFR increasing
around dawn.

Cigs increase after 13-14z but will likely bounce between VFR
and MVFR through the day in post-frontal NE winds. Most sites
have a 30-40% chance of prevailing MVFR through 00z. SHRA may
begin to develop near the coast Tuesday morning, eventually
spreading inland during the day with an accompanying risk of an
isolated TSRA. Expanded VCSH mention to all sites but continued
to hold off on TSRA mention given low confidence.

Outlook: A coastal low will deepen offshore mid to late week
supporting periods of RA, SCT TSRA, low CIGs, and breezy NE
winds.

&&

.MARINE...
A cold front will move slowly south into the northern waters
this evening and this should support easterly winds building to
10-15kt. South of the front, light easterly winds of 5-10kt are
expected. Winds will continue to build through the day Tuesday
as the front settles into the area, and as the gradient along it
begins to strengthen. By Tuesday afternoon, most waters are
expected to have northeast winds of 10-20kt. Seas of 2-3ft today
will build to 3-5ft by Tuesday afternoon.

Outlook: A notable coastal low is forecast to impact the area
mid to late week with a period of hazardous winds and seas.
Guidance differ some on the strength and the track of the low,
but confidence continues to increase in widespread gale-force
winds for most, if not all, waters, with winds peaking Thursday
into Friday. At the peak, the central and northern coastal
waters (nearshore and outer) may see gusts of 40-45kt.
Additionally, seas of 10-15ft+ are forecast for all outer
waters. For the nearshore coastal waters, seas of 8-12ft are
likely from Duck to Cape Lookout. South of Cape Lookout, seas of
4-8ft are forecast. The longer fetch across the Atlantic should
allow wave periods to build to 10-13s by Thursday and Friday.

Given the increased confidence, a Gale Watch has been issued
for portions of the central and northern coastal waters, as well
as the northern rivers and sounds. Gale-force winds may begin
as early as Wednesday morning, but most likely will begin
Wednesday afternoon and then continue into Friday. It looks like
there will be about a 24hr period of 25kt+ winds leading up to
the gales, and a Small Craft Advisory has been issued leading
into the Gale Watch for those same waters. Elsewhere, the Gale
Watch is likely to be expanded, but confidence in timing and
magnitude is lower.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...Small Craft Advisory from 5 PM Tuesday to 5 PM EDT Wednesday
     for AMZ131-150-230-231.
     Gale Watch from Wednesday afternoon through Friday morning for
     AMZ131-150-180-230-231.
     Small Craft Advisory from 8 AM Wednesday to 2 AM EDT Thursday
     for AMZ135.
     Small Craft Advisory from 8 PM Tuesday to 8 PM EDT Wednesday
     for AMZ152.
     Gale Watch from Wednesday evening through Friday morning for
     AMZ152-182.
     Small Craft Advisory from 8 AM Wednesday to 2 PM EDT Thursday
     for AMZ154-156.

&&

$$

DISCUSSION...RM
AVIATION...RM/MS
MARINE...RM