220
FXUS62 KMHX 182341
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
741 PM EDT Fri Jul 18 2025

.SYNOPSIS...
High pressure builds into Eastern NC through the weekend with
dangerous heat and humidity. A wavy frontal boundary will bring
scattered to numerous thunderstorms this afternoon into early
next week. The front will push through the area Monday, with
high pressure ridging in from the north through mid-week.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 145 PM Friday...

Key Messages

 - Severe thunderstorms with damaging winds and flooding
   possible through tonight

 - Dangerous heat to impact the area through Saturday

A weak cold front is currently draped west to east across
southern Virginia (as of 2pm). A very moist and unstable airmass
resides along and south of the front across all of ENC this
afternoon. The airmass is characterized by MLCAPE of 3000+ j/kg
and PWATs of 2- 2.25". Deep layer shear is weak (10-20kt), but
is relatively stronger than what we have seen the past few days.

The front is forecast to slowly drift south through tonight,
aided by the glancing influence of an upper wave passing well to
the north of the region. The front will provide an area of
increased low-level convergence, with a local max in convergence
where the front interacts with the various sea/sound/river
breezes. We`re currently seeing this in action across the NRN
OBX where scattered strong convection is ongoing. To the west
and south of that area, visible satellite shows some modest
cumulus development, but sustained convection has yet to develop
due to weaker convergence. With time, I expect convergence to
gradually increase as the front sinks further south into the
area, and this should lead to a gradual expansion in the
coverage of convection later this afternoon and, especially,
this evening into tonight.

Boundary-parallel storm motions, high PWATs, and a deep warm
cloud layer will support very efficient rainfall processes,
which favors high rainfall rates and the potential for flooding.
Ensemble mean guidance suggests a widespread 1-3" of rain
focused along the HWY 264 corridor. However, where training
convection occurs, rainfall amounts of 3-7" are within the realm
of possibility. Flash flood guidance is around 2-4" over a 6hr
period, which is well within the guidance envelope for rainfall
today. This, then, appears supportive of flooding and flash
flooding, and the Flood Watch continues to look solid for the
northern half of ENC.

Meanwhile, deterministic, machine learning, and ensemble
guidance show a moderate to strong signal for water-loaded
downdrafts with the tallest and most sustained cores today.
Additionally, the shear/instability combination appears
supportive of weakly rotating updrafts, which adds to the
damaging wind potential, but also potentially brings in a low-
end risk of large hail (up to quarter size).

The main question mark through tonight is how widespread the
convection will be. Guidance is mixed between 1) scattered
convection lasting through the night, and 2) a larger convective
complex developing and impacting much of the area. The
potential hazards are the same regardless, but scenario 2 would
lead to a larger area at risk.

Temperature-wise, heat indices are currently 105-110 degrees
for areas outside of ongoing convection, and the dangerous heat
will last into the evening hours.

&&

.SHORT TERM /SATURDAY NIGHT/...
As of 145 PM Friday...

The latest expectation is for a weak frontal boundary to be
stalled over, or just south, of ENC around sunrise Saturday
morning. This front is then forecast to lift north through the
day as a mid-level shortwave approaches the area from the west.
The combination of the advancing front and the shortwave should
support another round of convection on Saturday. That said, if
convection today and tonight is widespread, there is the
potential that the airmass will be slower to recover on
Saturday, which would tend to limit the coverage. The airmass on
Saturday is expected to be about the same as today, so where
convection does develop, there should be a subsequent risk of
gusty/damaging winds and flooding.

Dangerous heat is once again expected on Saturday. However,
with the front lifting north through the day, it`s possible that
the northern half of the area may not get quite as hot and
humid as areas to the south. While there is a risk of dangerous
heat areawide, the highest probability is south of HWY 70, and a
Heat Advisory has been issued for the highest confidence areas.
The advisory may need to be expanded if the front lifts north
faster than forecast and/or if convection through tonight isn`t
as widespread.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
As of 3 AM Friday...

Key Messages...

- Highest rain chances Sunday through Monday

- Potential for hazardous heat continues this weekend.

- Isolated diurnal storms possible Tuesday through Thursday

Frontal boundary lingers over NC/VA Sunday as high pressure
sits to our south. Shortwaves continue to ride along the
northern periphery of the high along the wavy frontal boundary
bringing elevated rain/tstorm probs through Monday. Sunday
ridging weakens over ENC with the SW shift of the high, bringing
temps down a notch (but still flirting with heat advisory
criteria). Monday a back door cold front moves through the
region, increasing PoPs to above climo as additional forcing is
expected to increase storm coverage. Tuesday through Thursday
subsidence aloft dries up the mid and upper levels, bringing
PoPs down as storm coverage along boundaries is expected to be
isolated to scattered at best. Dewpoints also drop to the upper
60s, leading to a very pleasant couple of days over ENC next
week.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /through 00z Sunday/...
As of 740 PM Friday...

Key Messages

 - Iso TSRA threat continues through tonight; renewed TSRA risk
   Sat afternoon

Busy evening for the airspace over eastern NC with strong
thunderstorms across the Albemarle Peninsula and more iso to sct
activity developing across the southern coastal plain. TSRA
activity likely continues through at least 03z, but environment
will remain marginally supportive for further iso shower
activity although confidence is too low to include in TAFs.
Outside of showers and storms, VFR conditions expected to
prevail.

Typical convective forecast for Saturday, starting dry but with
convection redeveloping along a stalled frontal boundary in the
afternoon and posing a threat for all terminals through at least
00z. Torrential rainfall and brief but severe visibility
restrictions are possible in the strongest storms.

LONG TERM /Saturday night through Wednesday/...
As of 330 AM Friday...There will be a chance for showers and
thunderstorms through Tuesday, bringing with it reduced vis and
cigs within thunderstorms. Tstorms could also bring frequent
lightning, torrential downpours, and gusty winds. There will be
a fog and low stratus threat at night as well with light to calm
winds and moist low levels, exacerbated by any areas that see
meaningful rainfall during the daytime.

&&

.MARINE...
SHORT TERM /through Saturday/...
As of 230 PM Fri... Cold front is currently noted to the north
near the Virginia Beach vicinity as of this update. This front
is expected to continue to slowly drop S`wards this afternoon
and evening eventually stalling tonight along our northern
sounds and waters before lifting north as a warm front on Sat.
Out ahead of this front, we already have ongoing shower and
thunderstorm activity, primarily across our northern waters, but
do expect continued shower and tstm activity to gradually
spread S`wards through the afternoon and evening. These storms
will bring a threat for strong wind gusts, frequent lightning,
small hail, and an isolated waterspout or two. Shower and
thunderstorm activity should gradually diminish late tonight.
Otherwise, recent obs generally show winds coming from a WSW to
SW`rly direction at 5-15 kts, though a few areas such as the
Pamlico Sound and central waters near Diamond Shoals Buoy have
slightly stronger winds closer to 10-20 kts with isolated gusts
up near 25 kts at times. Do not expect to issue SCA`s and any 25
kt gust will likely be infrequent in nature. As we get into
tonight expect winds to become light and variable near the
aforementioned frontal boundary in our northern waters with 5-15
kt SW`rly winds expected anywhere south of the front. As the
front lifts north on Sat, winds across the entire area become
S-SW`rly at 5-15 kts with gusts up near 20 kts. Seas along our
coastal waters generally remain around 2-4 ft.

LONG TERM /Saturday night through Wednesday/...
As of 2 PM Friday...As we get into the weekend ridging weakens,
allowing SW`rly winds to remain at 10-15 kts on Sun. Monday
morning a back door cold front moves through, bringing behind it
north/northeast winds 10-20kt which continues through Tuesday.
Seas 2-4 ft expected through the long term. Diurnal showers and
thunderstorms will be possible through the period, with highest
probs Saturday and Monday.

&&

.HYDROLOGY...
As of 145 PM Friday...

Boundary-parallel storm motions, high PWATs, and a deep warm cloud
layer will support very efficient rainfall processes through
tonight, which favors high rainfall rates and the potential for
flooding. Ensemble mean guidance suggests a widespread 1-3" of
rain focused along the HWY 264 corridor. However, where training
convection occurs, rainfall amounts of 3-7" are within the
realm of possibility. Flash flood guidance is around 2-4" over a
6hr period, which is well within the guidance envelope for
rainfall today. This, then, appears supportive of flooding and
flash flooding, and the Flood Watch continues to look solid for
the northern half of ENC.

An additional flood risk may develop over the weekend depending
on how widespread convection is, and if it occurs over the same
areas hit with the heaviest rain through tonight.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Heat Advisory until 8 PM EDT this evening for NCZ029-044>047-
     079>081-090>092-094-193>196-198-199-203>205.
     Flood Watch until 4 AM EDT Saturday for NCZ029-044>047-080-081-
     203-205.
     Heat Advisory from 11 AM to 8 PM EDT Saturday for NCZ079-
     090>092-094-193>196-198-199.
MARINE...None.

&&

$$

SYNOPSIS...MHX
NEAR TERM...RM
SHORT TERM...RM
LONG TERM...RJ
AVIATION...MS/RJ
MARINE...RM/RCF/RJ
HYDROLOGY...MHX