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000
FXUS62 KMHX 102016
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
416 PM EDT Wed Apr 10 2024

.SYNOPSIS...
A strong low pressure system and associated cold front will
impact Eastern NC into Thursday night. High pressure then
rebuilds into the area from the south this weekend into early
next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 400 PM Wednesday...

A 700mb warm front has lifted north of Eastern NC this
afternoon, with drying and warming aloft putting and end to the
isolated shower activity from earlier. The seabreeze has also
pushed well inland, with a southerly wind now dominant across
much of ENC.

Mid-level drying plus shortwave ridging aloft should tend to
limit shower activity for the remainder of the night. However,
close to sunrise Thursday, strengthening low-mid level moisture
transport may support a gradual increase in the chance of
showers developing from south to north. For now, I`ll keep pops
on the low side through the night in light of the above.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
As of 400 PM Wednesday...

**Strong cold front to bring multiple hazards Thursday/Thursday
 PM**

KEY MESSAGES

1) Increased risk of thunderstorms late Thursday into Thursday
night, some of which could be strong to marginally severe

2) Period of strong southerly winds Thursday into Thursday
night, with an increased risk of coastal impacts

FORECAST DETAILS

An upper level shortwave, and an associated surface low, will
lift NE from the TN Valley into the eastern Great Lakes
Thursday/Thursday night. East of the low, an effective warm
front will lift steadily north through the Carolinas on
Thursday. A pre-frontal trough is then forecast to push east
through ENC during the late- afternoon/evening hours, followed
by a cold front passage Thursday night.

Warmer temps aloft will tend to keep mid-level lapse rates on
the low side (<6 C/km), but strong low-level moisture advection
should allow a plume of weak instability to develop north ahead
of the advancing pre-frontal trough. Within this plume,
probabilistic guidance gives a 30-50% chance of SBCAPE >500j/kg.
Deep layer shear of 50-60kt+ is forecast, which sets up a
classic high shear/low CAPE scenario.

Based on the latest suite of model guidance, it appears that
the most likely scenario is for widespread rain and embedded
thunderstorms to develop north through Eastern NC Thursday into
Thursday evening as strong lift overlaps with a deepening layer
of moisture. In this scenario, convection would tend to be more
shallow in nature, but given strong flow aloft, could support
occasional gusts of 50+ mph thanks to enhanced mixing. SPC
currently has our entire area in a "Marginal" risk of severe
weather, and given the most likely scenario outlined above, this
seems perfectly reasonable.

While less likely, if instability ends up higher, and if the
early rain is less widespread, there could be an opportunity for
surface-based convection and a higher risk of severe weather
(ie. 60+ mph gusts and a few tornadoes). Of note, too, a well-
defined MCV is ongoing along the north-central Gulf Coast at
this time, and it`s unclear what, if any, impact this will have
on the weather, locally, on Thursday. Stay tuned...

Outside of the thunderstorm risk, a tightening pressure
gradient east of the advancing pre-frontal trough will support
strengthening southerly winds, with non-thunderstorm gusts of
30-40+ mph. These strong winds will continue into the early
evening hours, then lessen as the gradient relaxes in the wake
of the pre-frontal trough and associated convection.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
As of 0330 Wednesday...High pressure builds over the area from
the SW over the weekend and continues to dictate the local
pattern through the work week as it sets up offshore to the SE.

Friday and beyond...The front will move offshore and SFC high
pressure will build in behind it from over the Gulf of Mexico,
across Florida, and the Wern Atlantic over the weekend. Aloft,
the negatively tilted trough axis pivots through the FA late
Friday night leading to downsloping flow aloft into the start of
the work week. Worth noting that a weak and shallow shortwave
is expected to travel about the circulation of the still stacked
low, which will be located around Lake Huron. Some guidance is
showing a chance of showers associated with this wave. Am
skeptical of this as the wrap around moisture about systems like
this rarely make it past the mountains to the W. Have shown an
uptick in clouds through the day Fri with a SChc of light
showers over far NWern zones. Most likely scenario seems like
decent clouds coverage and maybe some sprinkles Fri afternoon.
Ridging aloft builds over SECONUS from the Gulf mid- week
onward.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM /through 18z Thursday/...
As of 100 PM Wednesday...

KEY MESSAGES

1) Increasing risk of sub-VFR conditions Thursday

2) Gusty south winds Thursday

FORECAST DETAILS

Skies cleared out quicker than forecast earlier today, allowing
improved heating. This in tandem with weak lift has allowed a
few SHRA to develop from KPGV east to near KFFA. It appears this
will be short-lived, and confined through 21z this afternoon.
After 21z, drier air aloft and weaker lift should lead to a
decreasing SHRA risk. Through tonight, drier air aloft and
nebulous lift should keep the risk of SHRA low. The lack of more
substantial low-level moistening should keep the risk of sub-
VFR CIGs low through the night as well. On Thursday, low-level
moisture advection will quickly ramp up around sunrise, followed
by an increasing risk of sub- VFR CIGs. SHRA may begin to
develop Thursday morning as well. However, the greater chance of
SHRA and TSRA looks to hold off until after 18z Thursday.

This afternoon, the seabreeze is expected to steadily work
inland, and the associated southerly wind shift is reflected in
the TAFs. A modest south wind continues overnight, then
increases on Thursday as the pressure gradient tightens, and as
daytime heating/mixing ensues. Gusts of 25-35kt will be common
as mixing deepens. Any SHRA that develops could lead to enhanced
mixing, with higher gusts, although this risk should hold off
until later Thursday into Thursday evening.

LONG TERM /Thursday night through Monday/...
As of 0415 Wednesday...Periods of SubVFR flight cats with gusty
winds expected late Thurs into Fri as strong low pressure
passing to the W and N sends multiple fronts through the area.
Lower CIGs and VIS should be expected during this time with
conditions improving behind the front on Friday with VFR flight
cats lasting through the weekend.

&&

.MARINE...
SHORT TERM /through Thursday night/...
As of 330 PM Wed...Southerly winds increase to 10-20 kt tonight
as strengthening low pressure lifts towards west TN/KY,
tightening the gradient over the waters. Seas 2-4 ft today,
building to 3-5 ft late tonight.

Winds and seas increase further on Thursday into the 20-25 kt
with gusts to 30 kt and seas inc to 5-10 ft. Winds/seas peak
Thu night just ahead of strong cold front. Gale watches upgraded
to warnings and expanded to all sounds and rivers beginning at
6 PM. Seas peak at 10-15 ft, highest south of Hatteras.

LONG TERM /Friday through Monday/...
As of 0420 Wednesday...

The first front pushes offshore early Friday taking the
strongest showers/storms with it, though weaker shower activity
may persist ahead of the secondary reinforcing front. Winds
become SWerly 15-20g25-30 between the two fronts Friday
eventually becoming Werly 15-20kt behind the second front.
Boating conditions improve through the weekend with sub SCA
conditions arriving Saturday afternoon.

&&

.TIDES/COASTAL FLOODING...
As of 330 PM Wed...Will maintain the Coastal Flood Advisory for
Ocracoke through the King Tide tonight due to the vulnerability
at the north end of the island.

Coastal Flood and High Surf Advisories remain in effect for potential
inundation 1-2 ft agl for Thur evening into Fri. Strengthening
Srly wind ahead of an approaching cold front that will cross
the area Thursday night. These strong winds, peaking around the
time of high tide Thursday night, will build seas and could
lead to periods of ocean overwash and beach erosion for southern
facing oceanside locales. The potential for soundside flooding
exists for areas along the northern half of Pamlico Sound ahead
of and just behind the front as well with winds becoming swrly
just after midnight Thu night.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Coastal Flood Advisory from 6 PM Thursday to 5 AM EDT Friday
     for NCZ047-081-195-196-199.
     High Surf Advisory from 8 PM Thursday to 2 PM EDT Friday for
     NCZ195-196.
     Coastal Flood Advisory from 6 PM Thursday to 9 AM EDT Friday
     for NCZ203-205.
     Coastal Flood Advisory until 8 PM EDT Friday for NCZ204.
     High Surf Advisory from 8 PM Thursday to 8 PM EDT Friday for
     NCZ204-205.
MARINE...Gale Warning from 6 PM Thursday to 2 AM EDT Friday for AMZ131-
     135>137-154-156-158-230-231.
     Gale Warning from 8 PM Thursday to 2 AM EDT Friday for AMZ150-
     152.

&&

$$
SYNOPSIS...MHX
NEAR TERM...RM
SHORT TERM...RM
LONG TERM...TL/CEB
AVIATION...RM/CEB
MARINE...TL/CEB
TIDES/COASTAL FLOODING...MHX