741
FXUS62 KMHX 092230
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
630 PM EDT Tue Jul 9 2024

.SYNOPSIS...
Diurnally driven shower and thunderstorm activity is forecast
through midweek before the next front approaches and interacts
with deep moisture lifting off the Southeast coast bringing
increased precipitation chances late week.

&&

.NEAR TERM /Through Tonight/...
As of 630 PM Tue...Have ended ts threat, and have only several
more hours of iso shower mention in coastal plain for the rest
of the night. Some coastal showers may creep ashore late tonight
into early Wed.

Prev disc...As of 305 PM Tuesday...Key messages for today:

1) It will be hot and humid again Wednesday with Heat Index
values of 100-104 degrees.

2) Widely scattered to scattered afternoon/early evening
showers and thunderstorms with locally heavy downpours are the
main threat on Wednesday.

The overall pattern will change little through Wed with upper
ridging centered over the western Atlantic ridging into the
area. The Bermuda high will continue to circulate deep moisture
as southerly flow persists across the region with PW values
around 2-2.5" (highest western zones). Current scattered
showers and a few thunderstorms will begin to weaken rapidly
early this evening with loss of heating. Not seeing much in the
way of lightning with todays storms so just some brief heavy
downpours are expected. Should be mainly dry overnight with the
exception of the immediate coast late when isolated off water
showers will be possible.

Another warm and muggy night with lows in the mid 70s inland
and upper 70s to around 80 along the coast.

&&

.SHORT TERM /WEDNESDAY/...
As of 305 PM Tuesday...It will be another sultry day Wednesday
across the region with dewpoints mostly in the mid 70s and temps
peaking in the low to mid 90s inland and mid to upper 80s along
the coast resulting in heat indices around 100-104 degrees in
the afternoon. We are forecasting dewpoints to mix down into the
lower 70s over the coastal plain where the hottest temps should
occur. If the dewpoints remain in the mid 70s then Heat Index
values will likely reach 105 degrees for an hour or two and a
Heat Advisory may need to be issued.

It looks like there will be a instability gradient across the
region with the most unstable conditions located across the
western half of the region where MUCAPES of 1500-2000 J/kg will
be. Again not expecting a lot of coverage but the greatest
concentration of convection should be located along and west of
Highway 17 and north of Highway 264. With PW values well in
excess of 2" locally heavy downpours will be the main risk.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
As of 300 AM Tuesday...

KEY POINTS:

-Typical summertime pattern expected Wednesday With warm temps and
Chc PoPs along the sea breeze.

-Rainy end to the week, likely heavy at times with localized
flooding possible. Friday afternoon/evening is of greatest concern
for flash flooding at this point. Low severe threat.

-Warm temps continue, with Heat Indices near or just above 100F
every day outside of Friday.


Wednesday: The remnants of Beryl move into the Mid-west, strong
Bermuda high keeps is in a southerly flow regime,and a upper level
low continues to meander offshore. As Beryl continues to move
northward well to our west, it interacts with the Bermuda high to
our east and forms a pinched pressure gradient. This pressure
gradient breaks apart the weak upper level low offshore, and the
resultant shortwave accelerates northward along the pinched
gradient. This will be the start of a train of shortwaves and weak
lows moving through the region along the western periphery of the
Bermuda high through the long term. Inland troughing on Wednesday
provides enough forcing for convection, primarily west of hwy 17.
Coverage is expected to be isolated to scattered, and as a result
have kept PoPs generally below 50%, highest for the coastal plain.
Weak shear environment continues, and with little to no upper level
support, severe threat remains low. It is worth noting however that
PWATs continue to be above 2", and any showers and thunderstorms
that develop are capable of producing torrential downpours and
localized minor flooding. Further to our west, cold front associated
with remnants of Beryl enters the Piedmont region of NC. Wednesday
night.

Thursday: Cold front stalls along the coastal plain Thursday as
southerly flow and resultant moisture advection from the pinched
gradient continues. Continued moisture advection, CAPEs in the 1-
2J/kg range, and the forcing from the stalled boundary will result in
scattered to numerous showers primarily along and west of hwy 17.
Continued the increasing trend for PoPS on Thursday, with the
coastal plain now near 70% chances and much of the CWA firmly in the
"likely" category. Once again, severe threat remains low, but high
PWATs and training storms could result in localized flooding
concerns. While precip is focused along the boundary, further to our
south another shortwave/weak low rides along the Bermuda high,
reaching offshore of FL/SC/GA by the end of the day. Highs in the
low 90s inland, upper 80s along the coast.

Friday: Stationary front continues to linger in the coastal plain,
but now the shortwave well to our south Thursday reaches ENC. This
will provide additional forcing in addition to the stalled boundary,
and as a result we are expecting a continuous stream of scattered to
numerous showers and thunderstorms with heavy rain. Have continued
to increase PoPs for Friday, and introduced categorical PoPs with
this update. Capped in at 75% for now, but if things continue to
trend upward, so will the PoPs. WPC has highlighted ENC in the
"Slight" (at least 15%) risk of flash flooding in their Excessive
Rainfall Outlook for Friday. While the entire region is under the
Slight, along and west of hwy 17 continues to be the area of
greatest concern due to the prior rainfall. Drought conditions will
likely be improved substantially by the end of the week. Severe
potential continues to be low with very little 0-6km shear. Friday
will be the (relatively) coolest day of the long term, with highs in
the mid 80s.

The Weekend: Weak zonal flow sets up in upper levels as the high to
our east slides a bit further south. The high coverage rainfall will
be generally out of the region by Saturday morning, although OBX
could see some lingering showers and thunderstorms on Saturday. In
the daytime, stalled frontal system along the coastal plain
continues to be an area of focus for increased shower and
thunderstorm coverage through the weekend. After the brief cool down
Friday, we jump back up to highs in the low 90s Saturday, mid 90s
Sunday.

Early Next Week: PoPs go back to climo with sea breeze convection,
and temps continue to be in the mid 90s inland, upper 80s for
beaches.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /Through Wednesday/...
As of 630 PM Tuesday...Mainly VFR conditions with light winds
are expected though the TAF period. Could see a brief period of
MVFR cigs over the coastal plain early Wed as low level
moisture begins to pool ahead of an approaching weak frontal
boundary.

LONG TERM /Wednesday night through Sunday/...
As of 4 AM Tuesday...Low ceilings and visibilities Thursday-
Saturday with multiple rounds of widespread showers and
thunderstorms expected. Early next week we transition back to a
typical summertime pattern with afternoon and evening T-storms
along and ahead of the sea breeze. Patchy fog and/or stratus
will be possible each night, with increased chances for areas
that receive rain.

&&

.MARINE...
SHORT TERM /Through Wednesday/...
As of 305 PM Monday...High pressure off the coast will continue
to produce S to SW winds 5 to 15 kt across the waters tonight.
On Wed the southerly flow will increase to 10-20 kt late as the
pressure gradient tightens a bit. Seas will be 2-4 ft through
the period.

LONG TERM /Wednesday night through Sunday/...
As of 4 AM Tuesday...Typical summertime pattern continues with
high pressure offshore and weak boundary and sfc trough inland.
Southerly winds will begin to increase a bit late week 10-20 kt
with gusts of 25+ knots possible with seas building to 3-5 ft
and some 6 footers near the Gulf Stream. SCA conditions possible
across the waters Thursday- Friday.

&&

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

&&

$$
SYNOPSIS...MHX
NEAR TERM...JME/TL
SHORT TERM...JME
LONG TERM...SGK/RJ
AVIATION...TL/RJ
MARINE...JME/RJ