236
FXUS62 KMHX 130211
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1011 PM EDT Mon Aug 12 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 /UNTIL 6 AM TUESDAY MORNING/...
As of 2200 Monday...Only minor adjustments needed to the near
term. Have sped up the clearing of skies which also caused me
to expand the area of potential fog development further E than
previously forecast. Heaviest shower activity has pushed well
offshore and have lowered PoPs to no higher than SChc for
another hour before clearing any mentionable PoPs over land
through the overnight.

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 /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
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 /TUESDAY 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 /02Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /Through 00z Tuesday/...
As of 1915 Monday...The TSRA risk has decreased from north to
south tonight as slightly drier air works in aloft and as lift
decreases. If sufficient breaks in the clouds occur, there will
be a risk of BR/FG and sub-IFR conditions. I have sped up the
rate of clearing skies which gives more confidence in the fog
potential mentioned in previous forecast. Have opted to include
a period of MVFR fog for EWN. A period of LIFR VIS is possible
(20-40% chance) if FG develops. BR/FG should mix out by mid-
morning Tuesday, with a lower TSRA risk through early Tuesday
afternoon. Light winds out of the NE early become slightly more
Eerly through the day but are expected to remain AoB 10kt. VFR
through the day Tuesday.

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
SHORT TERM...RM
LONG TERM...SK
AVIATION...RM/SK/CEB
MARINE...RM/SK/CEB
HYDROLOGY...MHX