949
FXUS62 KMHX 181943
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
343 PM EDT Sat May 18 2024

.SYNOPSIS...
Low pressure system and its associated fronts impact ENC this
evening before pushing offshore by Sunday morning bringing
unsettled weather to the area. High pressure ridging then builds
in from the north keeping much of the area dry through mid week
before the next potential frontal system late week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 330 PM Saturday...

KEY POINTS:

- There is a low end chance (~20-30%) for heavy to excessive
  rainfall today in ENC this afternoon and evening as a low
  transits across the area.

-There remains a low end chance (~10-30%) chance for isolated
 to widely scattered strong to severe thunderstorms this
 afternoon and early this evening before the threat diminisheS
 significantly later tonight.


Overall the general synoptic pattern has not changed much since the
previous update as a jet streak currently extends across portions of
the SE and Mid-Atlantic and should gradually push offshore while an
upper level trough continues to make its way E`wards across the
Southeast, eventually becoming centered over the Mid-Atlantic late
tonight into early tomorrow morning. Incoming shortwave will
continue to round the base of this trough this evening eventually
pushing overhead by early Sun morning. At the surface a quasi-
stationary warm front currently extends from NW to SE around
northern Pitt to Hyde County with S`rly winds as well as warm and
humid conditions to the south of this front while east to
northeasterly winds and much cooler conditions found to the
north of this front. Low pressure has begun to develop along
this boundary and will quickly push E`wards across ENC and off
the OBX by late tonight with warm front eventually turning into
a cold front and shifting SE`wards tonight as well behind the
departing low. For this evening left PoP forecast alone for the
most part as increasing shower and thunderstorm chances will
overspread the FA this afternoon and evening with heavy rain and
severe weather possible within this activity. Precip chances
then quickly lower from north to south behind the departing low
and front late tonight with only SChc PoP`s expected by Sun
morning across ENC. This is also forecast to gradually shift
winds from north to south to a northeasterly direction bringing
a much cooler and more stable airmass to ENC by early Sun
morning. Hi temps today have gotten into the low 80s to upper
70s south of the front while to the north highs have struggled
to get out of the upper 50s to low 60s. Lows tonight get into
the upper 50s to low 60s.

With the above noted, a low end heavy rain and severe threat will
remain in place across ENC this afternoon and extending into tonight
before diminishing significantly after about the 11PM-2AM timeframe.
Highest probs located just south of wherever the front sets up.
Morning sounding showed a saturated column with RH`s at 85% or
above in both low and mid levels, PWAT`s at 1.51 inches, long
skinny CAPE, and a warm cloud layer around 10000 ft across the
region. Sounding profiles don`t change much overall this evening
with PWAT`s forecast to stick around 1.5-2.0 inches especially
along and south of the aforementioned frontal boundary. This
will result in favorable conditions for heavy to excessive
rainfall this afternoon and evening with the primary risk area
noted around and just to the south of where the front stalls and
the low develops. With this environment in place, widespread
rainfall amounts of 1-2" are possible across the entire area.
Latest 12Z suite shows the potential for the heaviest showers to
bring rainfall rates of 1-2" per hour at times with HREF and
NBM probs showing a 10-30% chance for some locations to see
rainfall amounts as high as 3-5". The one limiting factor for
today will be the faster storm motions but if storms can train
over each other they would be very efficient rainmakers and it
would not be out of the question to see some isolated areas
receive close to this higher end amount resulting in at least a
low end risk for localized flash flooding.

The severe risk is a bit more uncertain as S`rly flow to the south
of this front combined with widespread breaks in the clouds
everywhere but the NOBX should result in fairly widespread
MLCAPE values around 500-1500 J/kg this afternoon and evening.
Widespread 30-40 kts of bulk shear will remain in place as well
with the one limiting factor for severe weather being forcing to
the south of this front which will remain limited. Either way
the area remains in a marginal (level 1 of 5) risk for severe
storms today with the primary hazard being damaging wind gusts
(40-60 mph) and small hail within the strongest storms. Greatest
threat for strong to severe thunderstorm activity will remain
relegated to along and south of the front.

&&

.SHORT TERM /SUNDAY/...
As of 330 PM Saturday... Upper level trough will be centered
over the Mid-Atlantic to start our day out with this trough
pushing offshore by SUn evening. Mid level shortwave will also
push offshore by SUn evening as well. AT the surface low
pressure off the coast will continue to push further out to
seas as high pressure wedges itself across the Carolinas from
the north bringing dry air to the region. Latest trends have
come in drier for SUnday as it looks like the low will be
farther away from the coast than previously thought which limits
moisture availability across the area. As a result have lowered
PoP`s to SChc across just about all of the area with further
reductions possible in coming updates. Otherwise steady NE`rly
flow will keep temps on the cooler side with highs only getting
into the 60s to near 70.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
As of 330 PM Sat...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.

Sunday night...Drier conditions ensue Sun night with lows in the
50s.

Monday through Thursday...High pressure builds across the Mid-
Atlantic. Expect dry conditions through Thursday, along with
steadily warming conditions. Temps will start out in the 70s,
then by Tue and esp Wed into Thu, rise through the 80s and back
above climo. Lows will be in the 50s to start the pd, then rise
into the 60s by mid week.

Friday...Next potential weather maker in the form of a
shortwave trough and approaching cold front may arrive by week`s
end, bringing threat for thundershowers to the region with a
warm/humid airmass in place by then. Lots of disagreement this
far out, so pops only in the 30`s% at best.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
SHORT TERM /through Sunday morning/...
As of 120 PM Saturday...A fairly complicated forest is on tap
today as we have several moving parts to the aviation forecast.
Currently have a mix of VFR to IFR conditions across ENC with
MVFR ceilings noted at the ISO/PGV TAF sites and VFR at EWN/OAJ.
Lowest ceilings can be found along the NOBX where E to NE flow
has kept low stratus in place. As we get into this afternoon and
evening a wave of low pressure will develop along a N`ward
moving warm front eventually pushing offshore tonight. As this
occurs shower and thunderstorm activity will quickly increase in
coverage and intensity this afternoon before waning late
tonight as the low and its associated fronts move offshore. As a
result expect VFR ceilings/vis to become MVFR/IFR at times
within any heavier shower or storm. Have also added in tempo
groups for potential tstm activity across all terminals starting
around 20Z across our northern most TAF sites and ending around
03Z at our southern most TAF sites. AFterwards we may see a
brief period of VFR/MVFR ceilings across ENC early this evening
before NE flow brings low stratus across all of ENC resulting in
widespread IFR/LIFR ceilings at all terminals. These IFR/LIFR
ceilings likely then persist through much of the morning with
clouds maybe lifting towards SUn afternoon to MVFR at times.
Otherwise expect winds to become NE`rly tonight from N to S with
winds gusting closer to 15-20 kts late Sun morning.


LONG TERM /Sun afternoon through Thursday/...
As of 4 AM Sat...A low pressure system will impact the area
through the weekend bringing periods of sub-VFR conditions. Pred
VFR conditions are expected early through mid week.

&&

.MARINE...
SHORT TERM /through Sunday/...
As of 330 PM Saturday... Quasi stationary warm front stretches
from NW to SE across the Pamlico SOund and adjacent coastal
waters this afternoon and shouldn`t move much until a developing
low pressure system to the west quickly tracks E`wards tonight
and brings this front south as a cold front tonight. To the
south of the front, 5-10 kt SW`rly winds with 1-3 ft seas are
noted while to the north of the front 5-10 kt NE`rly winds and
2-4 ft seas are noted this afternoon. Widespread shower and
thunderstorm activity is forecast to develop along this boundary
this evening, the strongest of which could produce gusty winds
of 34kt+ and small hail. As the low pushes offshore and the
front moves S`wards precip chances will lower after 06Z and
winds across all waters will shift from north to south to a
NE`rly direction and increase with widespread 15-25 kt NE`rly
winds with gusts up to 25- 20 kts expected across just about all
of our waters except the Pamlico/Pungo River. As a result, have
small crafts just about everywhere to account for this N`rly
surge. Elevated N`rly winds continue into Sun evening.

Seas will begin to build to 3-6 ft Saturday night into Sunday
morning within the strengthening northeasterly surge of wind behind
the departing low and remain around 3-6 ft with some 7 ft seas
possibly noted along the outer coastal waters Sun afternoon and
evening.

LONG TERM /Sunday night through Thursday/...
As of 4 AM Sat...A complex low pressure system will shift off
of the NC coast during the day Sun, with gusty nerly winds in
it`s wake. Solid SCA cond expected across all waters and sounds,
including Alligator River, through Sunday as winds inc to 20-30
kt. SCA cond linger into Monday evening for Pamlico Sound and
the coastal waters as moderately gusty ne winds keep seas
elevated and wind gusts aoa 25 kt. Seas expected to drop below 6
ft Mon night all waters as high pres begins to build in.

&&

.HYDROLOGY...
As of 340 PM Sat...A warm front will stall northwest to
southeast along and just south of hwy 264 (including Greenville)
this evening, with the potential for convection to train along
the boundary. If this occurs, max QPF guidance suggests rainfall
amounts as high as 3-5". This may occur over a relatively small
area, but is noteworthy coming on the heels of the recent round
of rain. Where/if this occurs, there would be a locally higher
risk of hydro/flash flooding concerns, and we`ll be closely
monitoring this potential.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...Small Craft Advisory from 4 AM to 8 PM EDT Sunday for AMZ131-
     230-231.
     Small Craft Advisory from 4 AM Sunday to 4 PM EDT Monday for
     AMZ135-150.
     Small Craft Advisory from 10 AM Sunday to 8 PM EDT Monday for
     AMZ137.
     Small Craft Advisory from 4 AM Sunday to midnight EDT Monday
     night for AMZ152.
     Small Craft Advisory from 8 AM Sunday to midnight EDT Monday
     night for AMZ154-156.
     Small Craft Advisory from 11 AM Sunday to midnight EDT Monday
     night for AMZ158.

&&

$$
SYNOPSIS...MHX
NEAR TERM...RCF
SHORT TERM...RCF
LONG TERM...TL/RCF
AVIATION...TL/RCF
MARINE...TL/RCF
HYDROLOGY...MHX