121
FXUS62 KMHX 271614
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1214 PM EDT Thu Jun 27 2024

.SYNOPSIS...
A weak cold front will move into the region today and stall just
south of the area tonight. High pressure then builds in behind
this feature from the north late week and into the weekend with
another front approaching late Sunday through Monday. High
pressure once again builds over the area from the north on
Tuesday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 1215 AM Thu...

Key Messages for today:
1) The combination of hot temperatures
(highs in the low to mid 90s) and high humidity levels
(dewpoints in the 70s) will result in dangerous Heat Index
values around 105 degrees from late morning through the
afternoon.

2) The atmosphere will become very unstable this afternoon
resulting in the development of scattered to numerous showers
and thunderstorms (especially this afternoon east of Highway
17). Some of the storms could become severe with damaging wind
gusts and hail to around 1" the main threats. Torrential
downpours could lead to localized flooding in poor drainage
areas.

While the sfc trough that pushed through the area this morning
has mostly moved offshore, several additional boundaries
are evident on satellite imagery across the region, including
sea/river breezes, a lingering trough across the central portion
of the FA, and a slow moving cold front pushing into US 64
corridor. These boundaries will be the focus for storms this
afternoon and are already seeing a line of thunderstorms develop
along the cold front. A marginal risk (1 of 5) of severe storm
continues with strong instability already in place with MLCAPE
around 1500-2500 J/kg and SBCAPE around 3000-3500 J/kg, however
shear remains meager at around 20-30 kt at best. The forecast
remains in good shape with minimal changes for the mid-day
update with greatest chances for strong storms between 2-8pm
today. The temps are currently in the mid 80s to around 90 with
heat indices around 96-102 and will maintain the heat advisory
across much of the coastal plain with heat peaking early to mid
afternoon before greatest convection develops.

Previous discussion...Active weather is on tap for the next 18
hours as a weak cold front moves into eastern NC this afternoon
then stalls just south of the area overnight. Ahead of the front
deep southerly flow will continue to usher a hot and humid
airmass into the Carolinas. Just how how it gets today has
become a little more uncertain as the 00Z MOS has come in cooler
with highs especially the ECMWF (upper 80s to lower 90s). This
may be resulting from the models thinking that debris clouds
associated with weakening convection currently moving into the
northern portion of the area will lingering and reducing
heating. The NBM is the warmest temp guidance (low to mid 90s)
and was used in this forecast package and resulted in peak Heat
Index values around 105 degrees this afternoon. Decided to not
expand the Heat Advisory north where clouds will be most likely
to persist and produce slightly cooler high temps.

This morning the models are in pretty good agreement with the
convection now entering the northern portion of eastern NC early
this morning. This activity will move southeast across the
northern portion of the area (mainly north of Highway 264) this
morning with an ending time around 15Z. Then the atmosphere will
become increasingly buoyant this afternoon with ML CAPES around
2500 J/kg resulting in scattered to numerous showers and
thunderstorms. Shear will be a little weaker ( around 20 kt)
than with the severe event this past Mon. The lack of shear may
be compensated by water loaded downdrafts as PW values are
forecast to exceed 2". Expecting pulsey multi-cell clusters
capable of producing damaging wind gusts and marginally severe
hail to around 1". In addition torrential downpours will lead to
localized poor drainage flooding. The high res models are
indicating the potential for 2-3" rainfall amounts in persistent
downpours. Storms should begin to blossom 17-19Z with the best
coverage expected east of Highway 17.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
As of 330 AM Thu...The strongest convection should be winding
down by 00Z with any lingering shower and thunderstorm activity
ending by midnight as the front sags southward and drier
northerly flow develops across the area. Could see patchy fog as
skies clear and winds becalm calm. Lows are projected to be in
the upper 60s to lower 70s inland and warmer low to mid 70s in
the beach communities.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
As of 330 AM Thurs... Once again the heat and humidity will be the
main story in the long term to start as high pressure ridging builds
overhead this weekend. Heat related impacts will be a threat
most afternoons through Sunday, with the most oppressive heat
potential both Saturday and Sunday. Scattered diurnal activity
is expected Friday through Sunday, with better chances for
precip arriving Sunday night and into Monday as another front
moves in. Expecting dry conditions from Tuesday into the end of
the period.

Friday... No significant changes to the forecast as a cold front
will be pushing offshore Fri morning and stalling. Behind this
front a marginally cooler/drier airmass will try to build in but
will not be very successful as humid conditions will persist
through the day. Scattered shower and thunderstorm activity will
be possible Friday afternoon as some instability and forcing
from sea/river/sound breezes will be in place across ENC and as
a result have kept SChc to CHc PoPs across the region with the
highest chances over the coastal plain.

Slightly cooler temperatures expected Friday behind the front as
high temps get into the upper 80s to low 90s, but with humidity
sticking around, it will feel like its about 95 to 100 F
outside.

Saturday through Monday... The heat and humidity return in full
force this weekend as high pressure ridging restrengthens over
the area. High temps will generally range from the upper 80s
along the immediate coast and OBX to the mid to upper 90s across
the Coastal Plain. Combined with the high humidity across ENC
heat indices will reach 100 to potentially 110 this weekend.
With lows only getting down into the 70s each night, there will
not be much relief overnight either resulting in an increased
threat for excessive heat.

Otherwise diurnally driven showers and storms will be possible
on Sat with increased precip chances on Sunday afternoon through
Monday with the approach of a cold front. This cold front will
track across the region on Monday with the precip threat
gradually ending from northwest to southeast Mon night. Given
the forecasted cloudcover and precip chances on Mon temps will
also be lower with Highs only getting into the 80s.

Tuesday through midweek...Behind this front next week the heat and
humidity looks to break finally with dry conditions and near normal
temps expected.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
SHORT TERM /through Tonight/...
As of 630 AM Thu...A period of mainly MVFR ceilings is expected
through about 14Z this morning then our attention turns to the
toward the scattered to numerous showers and thunderstorms
expected to develop this afternoon. Some of these storms could
become severe with winds gusts to 50 kt, large hail and
torrential downpours producing occasional sub VFR conditions.
Most of this activity will be east of the TAF sites by 00Z. The
combination of wet soils and radiational cooling could result in
patchy fog formation with sub VFR conditions after 6Z as winds
become calm.


LONG TERM /Friday through Monday/...
As of 345 AM Thurs... Diurnally driven shower and thunderstorm
activity is forecast across ENC on Fri and Sat with some
periods of sub-VFR conditions possible each afternoon and
evening. Another cold front will arrive late Sun and bring an
increased chance of sub-VFR conditions through Monday before VFR
conditions potentially return on Tuesday.

&&

.MARINE...
SHORT TERM /through Tonight/...
As of 630 AM Thu...SCAs continue for the sounds and northern
waters through 12Z. SSW winds continue 10-20 kt, gusting to 25
kt across the northern waters and sounds early this morning.
These winds are forecast to diminish to 10-15 kt gusting to 20
kt around 12Z this morning and continue through the afternoon.
Tonight winds will diminish to around 10 kt then become NE
behind the weak cold front forecast to cross the waters
overnight. Seas will be 2-4 ft today and 2-3 ft tonight.

Strong thunderstorms develop this afternoon into early evening,
with strong winds above 34 kt and hail possible.

LONG TERM /Friday through Monday/...
As of 345 AM Thurs... Decent boating conditions forecast
through Sat before a cold front tracks across our waters Sun
night into Monday bringing widespread shower and thunderstorm
activity as well as elevated winds and seas.

As a ridge of high pressure gradually builds in from the north on
Fri, northeast to easterly winds at 5-15 kts and 2 to 4 ft seas will
persist across our waters Fri into Fri night. As high pressure
ridging gradually slides offshore winds will turn to a SE`rly
direction on Sat. Winds will continue to gradually turn Sat
night into Sun to a SW`rly direction while also increasing to
10-20 kts as a cold front approaches from the west bringing our
next threat for unsettled conditions across the waters Sun
night into Mon. Seas will remain around 2 to 4 ft through the
rest of the period, though would not be shocked to see some 5 ft
seas near the Gulf Stream waters Sun night into Mon as the
front track across the area.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Heat Advisory until 5 PM EDT this afternoon for NCZ045>047-080-
     081-090>092-094-193>195-198-199.
MARINE...None.

&&

$$
SYNOPSIS...MHX
NEAR TERM...JME/SK
SHORT TERM...JME
LONG TERM...RCF/RJ
AVIATION...JME/RCF
MARINE...JME/RCF