534
FXUS62 KMHX 171508
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1108 AM EDT Fri May 17 2024

.SYNOPSIS...
A frontal boundary will stall across the waters today, then
shift east tonight as another area of low pressure approaches
from the west. That low will impact the area through early next
week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 1045 AM Friday...

Surface analysis this morning shows a well-defined low
offshore, east of ENC. In the wake of the low, a stationary
frontal boundary stretches north to south along the coast of the
Mid- Atlantic. Locally, this boundary has reached about as far
west as the mouth of the Pamlico River and Ocracoke. This
boundary separates mid 70s temps to the west, and low 60s to the
east. West of this boundary, a weak area of low pressure was
noted over central NC, with a subtle confluence boundary
stretching SE to the Crystal Coast.

Boundary layer moistening/destabilization along the above-
mentioned confluence zone should support at least an isolated
coverage of thunderstorms developing by early this afternoon.
Recent short-term guidance continue to support this potential as
well. The ongoing forecast handles this potential well, so
significant changes were not needed on the precip side. The main
forecast change was to increase cloudcover along the Outer
Banks based on recent satellite trends. I also lowered highs
along the OBX for today given the potential for clouds lingering
longer than originally forecast.

Of note, recent RAP guidance suggests deep layer shear may
increase to 35-40kt this afternoon. While instability is
forecast to be weak, the increase in shear at least loosely
opens the door for a strong storm or two (mainly a gusty wind
threat). Overall, though, the risk of severe weather still
appears low (<5% chance for the area at large).

PREVIOUS DISCUSSION..Upper ridging continues to build in from
the SW this morning, resulting in mostly clear skies and light
winds for much of mainland ENC. Fog is quickly dissipating this
morning, and lows reached the upper 50s to low 60s this morning.

Ridging crests over the area Friday but shortwave energy will
be approaching that could aid in initiating a few showers and
thunderstorms during the afternoon, generally along the
seabreeze as it migrates inland. Instability will be approaching
1kJ/kg for SW portions of the CWA and the ridging aloft keeps
kinematics less than impressive, in turn limiting any severe
potential. However a rumble of thunder or two from storms that
collapse as quickly as they form can`t be ruled out. Area of
highest moisture convergence and instability in the afternoon
and evening Friday continues to be Duplin/Onslow/Jones/Lenoir
counties as the sea breeze advances, highlighting this area for
the greatest thunder potential. MaxTs a few ticks warmer than
Thursday for inland zones, low 80s most. Cooler Ts expected
along the coast where marine air will be felt as the seabreeze
penetrates further inland than Thurs.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
As of 700 AM Friday...A southern stream wave will transport
ample gulf moisture into the region Friday night into Saturday.
Showers and thunderstorms will slowly move eastward through the
short term while a sfc low approaches from our west. Severe
potential and heaviest rainfall will be occuring through the day
Saturday. See the long term discussion section for more
information.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
As of 400 AM Friday...A complex low pressure system will impact
the region through the weekend. High pressure builds in from the
north for the first half of the workweek. A cold front will
approach from the west toward the latter half of the week.

Saturday through Sunday night...A complex low pressure system
will impact the region through the weekend. A southern stream
wave will transport ample gulf moisture into the region
Saturday with sfc low pressure moving across the region late
Saturday or early Sunday. An unstable environment will be in
place ahead of the low with fcst CAPEs around 1500-2000 J/kg
along with 40-50 kt 0-6km bulk shear that could provide support
for strong to severe thunderstorms. SPC has upgraded the outlook
to include a Slight Risk (2 of 5) of severe storms across areas
south of the Pamlico River and continues a Marginal Risk (1 of
5) across the northern portion of the FA. The low will push
offshore Saturday night with northerly flow ensuing as high
pressure begins to ridge southward across the Mid-Atlantic
bringing a more stable environment across the area, however the
upper trough will slowly push across the area Sunday continuing
to bring showers across the region. Beneficial rainfall is
expected with much of the area forecast to receive around 1-2"
with locally higher amounts possible through the weekend.

Monday through Thursday...The upper low slowly slides southward
early next week with high pressure building across the Mid-
Atlantic. There could be a few lingering showers early next
week, especially along the coast, but otherwise expect dry
conditions through Wednesday. Guidance is a bit slower with a
mid level shortwave and attendant cold front approaching the
area which now looks to move across the area late Thursday, but
moisture continues to appear limited with deep layer westerly
flow providing subsidence to the lee of the Appalachians.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /through Friday Night/...
As of 715 AM Friday...VFR conditions today with the exception of
OBX, where low stratus from the deepening low offshore is
keeping conditions sub-VFR. We have a slight chance of
thunderstorms developing along and ahead of the sea breeze this
afternoon and evening, with temporary sub-VFR conditions
possible with the storms. Tonight will bring another round of
MVFR becoming IFR conditions as moisture advects in from the
west ahead of a sfc low. Showers and slight chance of thunderstorms
accompanied by lower vis and low ceilings on tap for tonight
into Saturday morning.

LONG TERM /Saturday through Tuesday/...
As of 430 AM Friday...A low pressure system will impact the
area through the weekend bringing periods of sub-VFR conditions
Friday night through Sunday. Pred VFR conditions are expected
Monday into Tuesday.

&&

.MARINE...
SHORT TERM /Today and Tonight/...
As of 1045 AM Friday...

Winds and seas have been a bit higher than forecast this
morning, and the forecast has been adjusted to reflect this
trend. Both are still on the margins for a Small Craft Advisory,
though, and guidance suggests both will lay down by this
afternoon. Given all of the above, I`ll opt to go with no
headlines given the marginal, and expected shorter-duration, of
the hazards.

PREVIOUS DISCUSSION...Seas are 2-3ft this morning, with winds
generally northerly near 10 kts with the low spinning offshore.
Onslow Bay and Neuse river are more westerly, away from the
influence of the low. Seas respond to winds Fri becoming 2-4ft
from N to S, 3-5ft over outer central waters. Winds veer to
become southeasterly through Friday night as a sfc low
approaches from our west.

LONG TERM /Saturday through Tuesday/...
As of 445 AM Friday...A complex low pressure system will impact
the region Friday night through Sunday bringing unsettled
weather through the period. Guidance for the most part keeping
conditions below SCA criteria through Saturday night as low
pressure transits the Southeast. The best opportunity for SCA
conditions will develop Sunday and continue through Monday with
N to NE winds around 20-25 kt and seas building to 5-8 ft as
low pressure deepens as it pulls offshore. Conditions gradually
improve Monday night into Tuesday with seas expected to drop
below 6 ft during the day Tuesday. There are differences among
the models the timing and track of this system, so be sure to
follow updates as details come into focus.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...None.

&&

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