920
FXUS62 KMHX 130517
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
117 AM EDT Tue Aug 13 2024

.SYNOPSIS...
Cold front pushes offshore tonight while high pressure builds in
from the north. High pressure will then remain over the Eastern
Seaboard into this weekend.

&&

.NEAR TERM /OVERNIGHT/...
As of 115 AM Tue...No significant changes were made on this
update outside of speeding up the start time of patchy fog
across the region. Otherwise muggy and warm conditions are
expected for the rest of tonight with continued patchy fog
across areas along and west of Hwy 17 tonight.

Previous Disco...As of 345 PM Monday...

 - Heavy rain/flooding risk continues through early this
   evening

 - Flood Watch in effect until 10pm tonight

 - Overnight fog potential

Early this afternoon, an area of low pressure was analyzed near
Columbia, SC. A stationary frontal boundary extends from
central SC east out into the SW Atlantic. North of the SFC
boundary, there appears to be an elevated (925-850mb) front from
Charlotte east through around Morehead City. It`s this
boundary, plus a modest upper level shortwave aloft, that will
be the focus for showers and thunderstorms through this evening.
Based on radar and satellite trends, it appears the greatest
risk of deeper convection will be focused along and south of HWY
264. The previous shift nicely outlined this area with the
Flood Watch, and this continues to look solid.

In the wake of this afternoon`s shortwave, subsidence and
drying aloft should lead to a decreasing chance of thunderstorms
from north to south. If sufficient clearing occurs overnight,
there will be an increased risk of fog development. A period of
dense fog cannot be ruled out, especially across the coastal
plain.

&&

.SHORT TERM /WEDNESDAY/...
As of 1245 PM Monday...

 - Scattered afternoon thunderstorms possible

Any areas of fog should mix out by mid-morning, with several
hours of dry conditions expected through early afternoon. By mid
to late- afternoon, another shortwave aloft combined with lee
troughing at the SFC should support isolated to scattered
thunderstorms. I expect the primary focus to be upstream across
central NC, but storms may have a tendency to move east into the
coastal plain of ENC thanks to increasing flow aloft.
Instability is forecast to be weaker on Tuesday compared to
today, but deep layer shear will be stronger, so there`s at
least some support for a stronger storm, or two.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
As of 5 AM Monday...A drying trend will commence mid-week as a
cold front offshore slowly sags southward and high pressure
builds into the area from the NW. However, upper trough remains
centered over the eastern CONUS with a series of shortwave
trough pushing across the area that will aid in initiating
isolated to scattered showers and thunderstorms at times.
Greatest chances will be during the afternoon/evening hours when
instability is maximized. PWATs lower to below 1.25" on
Wednesday so storms will not be the prolific rain makes that we
have been experiencing over the past week. Temps will actually
be a couple of degrees below normal with highs in the mid 80s
and it won`t be quite as oppressive humidity with dew point
temps in the mid to upper 60s.

The upper trough pushes off the East Coast Thursday and Friday
with upper ridging building in from the west. We will be closely
watching the current PTC #5, likely to become Ernesto later
today, as it pushes across the Caribbean Island through the
week. Current NHC forecast is for it to lift north of the
Greater Antilles as it interacts with the departing upper trough
and track well east of the area late in the week. While we are
not expecting direct impacts from this system at this time,
large swells are expected to impact the beaches bringing an
increased rip current risk and large surf beginning Friday and
continuing through the weekend. Locally, high pressure will
continue to dominate across the area and we will finally get a
couple of days to dry out. Temps will continue slightly below
normal with highs in the mid 80s and dew point temps in the mid
60s.

An upper low moves into the Great Lakes Friday into the weekend
with an upper trough digging back into the East Coast and a cold
front slowly advancing toward the area bringing increasing
chances for showers and thunderstorms across the region Saturday
and Sunday. Seasonable temps continue with highs generally in
the mid 80s.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /Through 06z Tuesday/...
As of 115 AM Tue... Mo clear skies and a mix of VFR and MVFR
visibilities are currently noted across ENC this evening. With
recent rains across the area, light winds, and mo clear skies,
still expect some combo of either low stratus or patchy fog to
overspread much of the area along and west of Hwy 17 resulting
in at least a general threat for widespread MVFR to IFR
ceilings/vis for the remainder of tonight into daybreak across
those areas. HREF probs still show a low end threat (20-30%) of
LIFR vis but given the recent trends have elected to cap lowest
Vis at IFR. Areas east of Hwy 17 likely staying at VFR/MVFR as
winds are slightly stronger here thus reducing the patchy fog
threat. As we get into the morning on Tue any leftover fog will
burn off and a SCT deck of diurnal Cu should gradually
overspread the area Tue afternoon but ceilings and vis should
become VFR Tue morning and remain VFR through the rest of the
period. Think TSRA potential will be very low (<15%) but a few
showers could pop up tomorrow afternoon especially across the
western TAF sites. Given the lower probability for showers and
storms have kept any precip mention out of the TAFs for now.
Light winds out of the NE early become slightly more Eerly
through the day but are expected to remain AoB 10kt.

LONG TERM /Tuesday night through Saturday/...
As of 530 AM Monday...Chances for sub-VFR conditions will
gradually diminish through the week as high pressure builds in
and we finally begin to dry out. Isolated to scattered showers
and thunderstorms chances continue into Wednesday that could
bring brief sub-VFR conditions with dry weather expected
Thursday and Friday. Light winds and good radiational cooling
conditions will continue to bring the chance for late
night/early morning fog and stratus most morning, especially
giving the saturated ground.

&&

.MARINE...
SHORT TERM /through Tuesday/...
As of 2200 Monday...Front has sunk S, currently 50mi S of Cape
Lookout, carrying the heaviest convection with it. Have lowered
PoPs quite a bit through the overnight hours, but continue to
carry at least SChc over the Sern waters.


Previous Disco as of 215 PM Monday...
 - Improving boating conditions by Tuesday

An upper level wave moving through will support scattered to
numerous thunderstorms across area waters through this evening,
with a decreasing risk tonight into Tuesday. Outside of the
thunderstorms, the area will be in a northeasterly flow of
5-15kt. The wind will be high enough to support 3-4 ft seas
through Tuesday, but all things considered, conditions will be
improving compared to the past several days.

LONG TERM /Tuesday night through Saturday/...
As of 6 AM Monday...Good boating conditions through much of the
week with high pressure building into the area bringing NE winds
around 5-15 kt through Friday. Wind finally begin to veer to E
and SE late Friday into Saturday as the high moves offshore.
Seas will generally be around 2 to 3 ft through early Friday but
then we will begin to see long period swells from soon to be
Ernesto begin to move into the waters late Friday which will
build through the weekend.

&&

.HYDROLOGY...
As of 2200 Monday...Was able to cancel the flash flood watch
early with convection pushing offshore faster than previously
forecast.

River flooding will continue across many river basins including
the Trent, Neuse, New and Tar Rivers as well as several
tributaries to the rivers through the weekend and into next week
with abundant rain falling will upstream of the FA. It should
be noted that some of the worst river flooding is still yet to
come, with some rivers not cresting until late this week or this
weekend.

&&

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

&&

$$
SYNOPSIS...MHX
NEAR TERM...RM/CEB/RCF
SHORT TERM...RM
LONG TERM...SK
AVIATION...SK/RCF
MARINE...RM/SK/CEB
HYDROLOGY...MHX