417
FXUS62 KMHX 301441
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1041 AM EDT Sun Jun 30 2024

.SYNOPSIS...
Hot and humid conditions persist today ahead of an approaching
cold front. The front will move through the area tomorrow
morning with high pressure building back into the area from the
north on Tuesday. Oppressive heat and humidity build back in
over the second half of next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 10 AM Sun...Expanded the Heat Advisory to the coast this
morning with the expectation of near 80 degrees dewpoints
holding on here through the afternoon. Also, expect heat indices
to reach around 110 across the coastal plain now with air temps
climbing into the upper 90s as precip mostly holds off until
late afternoon.

Latest analysis this morning depicts weak flow aloft over
eastern NC while a shortwave over southern Canada aids in
deepening low pressure over Quebec, with the attendant cold
front stretching into the western Great Lakes southward into the
Southern Plains. Ahead of this front, well defined surface
trough sits in the lee of the Appalachians.

Main focus for today`s forecast will be hot and humid
conditions, giving way to afternoon and evening convection.
Highs today are expected to soar into the mid to upper 90s
inland, and near 90 along the coast. Combined with Tds in the
mid 70s thanks to moist southerly flow, heat indices will rise
above 105 for many locations this afternoon. This required the
continuance of a Heat Advisory for this afternoon.

The aforementioned heat and humidity will drive up instability
this afternoon, rising to near 2000 J/kg SBCAPE. The
aforementioned lee trough will serve as the initiation point for
storms today, primarily in multi-cluster cells given only
marginal shear of around 20-25 kt. Activity will not reach the
coastal plain until mid-afternoon at the earliest, but pre-storm
environment will be favorable for storms capable of damaging
down bursts, especially owing to precipitation loading as PWATs
climb well above 2" and hi-res guidance depicts thin skinny CAPE
profiles. SPC has our entire area in a Marginal (Level 1 of 5)
risk for severe thunderstorms to convey this risk. Torrential
rainfall is likely in storms, and LPMM rainfall forecasts from
the HREF show the potential for isolated totals of 3-4 inches in
the most efficient storms. Despite dry antecedent conditions,
flash flooding is possible primarily in urban or poor drainage
areas. Inland areas are in a Marginal Risk of excessive rainfall
from WPC.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
As of 430 AM Sun...Earlier activity will lose organization and
severity as the sun sets tonight, but a second round of showers
and thunderstorms are likely, especially after midnight, as the
main cold front approaches and then crosses eastern NC. Very
high PWATs will remain in place ahead of the boundary, providing
a continued favorable environment for torrential rainfall and
potentially exacerbating any flooded areas from the afternoon
convection.

Another sultry night expected ahead of the front, but much drier
air will filter in behind the boundary being felt most across
the northwestern coastal plain by Monday morning as Tds fall
into the low 60s. Lows range from the mid to upper 70s along the
coast to upper 60s to around 70 north and west of Highway 64.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
As of 315 AM Sun...

KEY MESSAGES:

Cooler than average temps are forecast on Tue and Wed

Oppressive heat and humidity return Fri through Sun

Monday through Wed...Cold front will be tracking across the
region on Monday and push offshore by the evening hours with
scattered shower and thunderstorm activity noted along and out
ahead of the front. Heavy rainfall will be possible within any
of the stronger storms as activity will be highly efficient
rainmakers. Otherwise, expecting to gradually dry out from
north to south Mon afternoon as the front begins to push
offshore with S`rly winds in the morning shifting to a N`rly
direction behind the front with some gusts up near 20 mph at
times Mon afternoon. Highs won`t change much from the morning
temps only getting into the upper 70s to low 80s given
cloudcover and widespread precip.

Cold front will be well offshore by Mon evening with high
pressure ridging building in from the north and west overnight.
Outside of a few lingering showers along the Crystal Coast and
OBX and a few rumbles of thunder offshore early Mon evening, the
area should remain relatively dry Mon night with cloud cover
clearing from north to south through the night. Will have a
steady but light NE wind through the evening as well behind the
departing front which should limit any potential fog threat.
Cooler temps persist behind this frontal passage as well with
lows Mon night getting down into the upper 50s to low 60s
inland, and upper 60s to near 70 along the OBX.

Ridging gradually slides E`wards Tue and Wed bringing fair weather
to ENC as well as below avg temps. Highs get into the mid to upper
80s and lows get into the 60s each night. With dewpoints much lower
behind the front as well, it will feel more comfortable outside.

Thurs through Sat...Upper ridging will remain overhead into next
weekend as any upper level troughs struggle to dig S`wards. At the
surface, high pressure ridging will continue to push further
offshore allowing return flow to resume across ENC. This will bring
a return to oppressive temps and humidity especially Fri and Sat
which could threaten to bring more heat related impacts to the area
next weekend.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /through 12Z Mon/...
As of 715 AM Sun...Occasional MVFR cigs are holding over the
Outer Banks with a persistent area of weak showers offshore.
Further inland, outside of spotty ground fog VFR prevails under
a veil of thin cirri. South to southwesterly winds range from
5-10 kt ahead of a surface trough in the lee of the
Appalachians.

Main aviation focus will turn to an organized band of showers
and thunderstorms, expected to initiate ahead of the
aforementioned lee trough and advance towards the coastal plain,
with upscale growth into a squall line. Line will reach the far
inner coastal plain by 21z and quickly push southeastward into
the early evening. Pre-storm environment favors frequent
lightning, torrential rainfall lowering visibilities to IFR or
worse, and wind gusts in excess of 40 kt.

Activity will slowly fall apart in the evening, but another
round of frontally-forced convection will begin to approach the
terminals from the north by the end of the TAF period. This band
has higher probabilities of more predominant MVFR (70-80%
chance) and potentially IFR cigs (30-40%) associated with it.
Once again, a torrential rainfall threat may lower restrictions
briefly below IFR.

LONG TERM /Monday through Thursday/...
As of 320 AM Sun... Sub VFR conditions are forecast across the
area on Monday as a cold front tracks across the region bringing
a threat for widespread low stratus and reduced visibility in
any rain or thunderstorm activity that occurs with this frontal
passage. In addition to this, SW`rly winds Mon morning will
quickly shift to a N`rly direction from north to south and gust
to around 15-20 kts at times Mon afternoon before winds ease Mon
night. A return to primarily VFR conditions is then forcast Mon
night into the end of the period as high pressure ridging sets
up overhead.

&&

.MARINE...
SHORT TERM /Today and Tonight/...
As of 440 AM Sun...Regional observations across eastern NC show
southwesterly winds of 10-15 kt across all waters ahead of a
surface trough in the lee of the Appalachians this morning, with
seas of 3-4 feet. A stronger cold front is currently dropping
out of the Ohio Valley and is expected to work its way across
the waters early Mon morning.

Southwesterly flow will continue to gradually increase through
the afternoon ahead of the trough, and HREF probabilities show a
high likelihood (80-90% chance) of SCA force gusts developing
across area sounds and offshore waters by this afternoon and
into the evening hours. Therefore, headlines were introduced
this morning for most waters beginning 18-20z today. Headlines
extend well into Monday as winds turn behind the front (see LONG
TERM for details), but there will be a lull in winds just ahead
of the front itself which will last for a few hours. Seas will
reach up to around 4 feet for all waters.

Ongoing showers over the wall of the Gulf Stream this morning
will gradually ebb through morning. Showers and thunderstorms
are likely to impact most waters late this afternoon and
evening, with a second round immediately ahead of the
approaching cold front. The storms will be capable of torrential
rainfall and potentially damaging downbursts.

LONG TERM /Monday through Thursday/...
As of 330 AM Sun... Cold front will be tracking across the
region on Monday bringing widespread rain and thunderstorm
activity to our waters to start the period. SW`rly winds at 10
to 15 kts with gusts up around 20 kts out ahead of the front
will quickly shift to a N`rly direction behind the front at 15
to 20 kts with gusts up to 20 to 30 kts at times keeping SCAs
across our coastal waters and eastern sounds. Front should push
offshore and out to sea by Mon night with gusty winds quickly
diminishing to 10 to 15 kts and gusts to 20 kts by Tue morning
ending SCAs across our waters. Fair weather and benign boating
conditions are then forecast from Tue to the end of the period.
Winds will continue to ease Tue and Wed as high pressure ridging
extends over the our waters eventually down to 5 to 10 kts
while veering to an easterly direction by Wed. WInds eventually
become S`rly at 10-15 kts by Thurs as ridging shifts E.

2 to 4 ft seas will increase behind the aforementioned cold
front to 3 to 5 ft as winds increase Mon night. A few 6 ft seas
will be possible mainly along the Gulf Stream waters Mon night
as well. As we get into Tue and beyond, as the winds ease seas
will also lower down to 2 to 4 ft by Tue and remain at these
heights into the end of the period.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Heat Advisory until 8 PM EDT this evening for NCZ029-044>047-
     079>081-090>092-094-193-194-198.
     Heat Advisory until 8 PM EDT this evening for NCZ195-196-199-
     203>205.
MARINE...Small Craft Advisory from 2 PM this afternoon to 9 PM EDT
     Monday for AMZ135.
     Small Craft Advisory from 2 PM this afternoon to 8 PM EDT
     Monday for AMZ150-231.
     Small Craft Advisory from 5 PM this afternoon to 6 AM EDT
     Tuesday for AMZ152-154-156.
     Small Craft Advisory from 11 PM this evening to 6 AM EDT
     Tuesday for AMZ158.

&&

$$
SYNOPSIS...MHX
NEAR TERM...SGK/MS
SHORT TERM...MS
LONG TERM...RCF
AVIATION...MS/RCF
MARINE...MS/RCF