142
FXUS62 KMHX 111604
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1204 PM EDT Thu Jul 11 2024

.SYNOPSIS...
A cold front will become stalled across the region today through
Saturday with moist southerly flow bringing periods of heavy
rain. The front will dissipate early next week with hot temps
and the potential to heat indices in excess of 105 degrees
returning.

&&

.NEAR TERM /TODAY/...
As of 1145 AM Thursday...

- Continued flash flood risk through this afternoon

Surface analysis currently shows a stalled front draped NE to
SW across the coastal plain of ENC. A moist and very unstable
airmass (MUCAPE >3000 j/kg) exists to the east of the front,
with southeasterly winds continuing to push this airmass into
the frontal zone. This has supported a broken band of
thunderstorms for much of the morning, with very intense
rainfall rates. Within this area, rainfall amounts of up to 5-6"
have been measured, with hourly rates exceeding 2". Despite
recent dry conditions, the intense rainfall rates are clearly
overcoming the dry antecedant conditions, with multiple reports
of flash flooding this morning.

Moving into this afternoon, the evolution of convection is less
clear. An upper low approaching from the east may help push the
front west with time, which would tend to allow the focus for
convection to shift west as well. That said, debris clouds
blowing west off the morning convection has limited heating west
of the ongoing convection, and consequently has limited the
amount of destabilization. Meanwhile, the airmass to the SE of
the ongoing convection is very unstable, and lift appears to be
focused along both the front and various outflow boundaries. I`m
inclined to think the convection this afternoon will be focused
along and east of the ongoing convection, with less confidence
to the west. Given all of the above, a Flood Watch has been
issued for much of the coastal plain. The watch covers areas
east of the ongoing convection with the expectation that
convection will tend to edge east with time. We`ll continue to
re-evaluate this potential into this evening.

The combination of a persistent area of forcing, very slow
storm motions, strong instability, and PWATs of 2-2.5" will
favor a continued risk of intense rainfall rates and flash
flooding.

&&

.SHORT TERM /TONIGHT/...
As of 415 AM Thursday...The upper pattern remains similar
tonight with the aforementioned upper low off the Southeast
gradually filling while approaching the Carolina coast. The sfc
front is progged to slide westward into the piedmont with a weak
sfc low off the GA/SC coast. Numerous showers and isolated
thunderstorms expected to continue across the region but with
waning instability, weakened convergence with the front to the
west, and mid/upper level drying ahead of the upper low lowering
PW values to around 2", rainfall amounts are not expected to be
as high overnight. Still could see an additional 1/2-1" across
inland areas while coastal sections will continue to see lower
amounts. Lows generally expected in the mid to upper 70s.

&&

.LONG TERM /FRIDAY THROUGH THURSDAY/...
As of 330 AM Thursday...
Key Messages:

-Very wet period expected Friday and Saturday possibly lingering
 into Sunday, with heavy rain chances likely (70-80%) at times
 with localized flooding possible. Severe threat remains
 relatively low at this time. 4-6 inches of rain possible west
 of highway 17.

-Warm and humid conditions continue. Sunday through Wednesday
 heat indices of 105-110 degrees are possible each day.

Not many changes to the forecast over the last 24 hours. Wet and
warm will be the story for the long term forecast as a frontal
system extending southward into the Carolinas becomes nearly
stationary for Friday and Saturday. This feature will remain
between high pressure offshore and lower pressure to the north and
west. This pattern will facilitate extremely efficient moisture
transport off of the Atlantic over the Carolinas. This is highlighted
by the ECMWF extreme forecast index which is showing anomalously high
precipitation values over the Carolinas. In addition model soundings
show PW values approaching 2.5 inches at times. Friday will see
higher concentration of QPF west of highway 17 with a broader area
of lesser amounts on Saturday across the CWA as the front begins to
push eastward.

With Friday being the most likely day for any kind of flooding
issues, WPC has a slight risk of excessive rainfall across all of
eastern North Carolina. That being said, antecedent conditions have
been dry and therefore it will likely take some training of
convection for a period of time to produce flooding.

While there will also be a chance for thunderstorms each day, the
chances for severe weather remain underwhelming. While there will
certainly be enough moisture and instability to initiate convection,
shear values are lacking. Thus the heavy rain is the primary threat
during this time period.

Not to be overlooked in the long term is the threat for extreme
heat, particularly beginning on Sunday through Wednesday. Expect high
temperatures in the low to mid 90s inland with upper 80s to low 90s
along the coast. Heat index values will push or exceed 105 degrees
each day in most locations except the extreme coastal areas.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
SHORT TERM /Through Tonight/...
As of 7 AM Thursday...Pred sub-VFR conditions are expected
through much of the TAF period as a front stalls across rtes
this morning bringing numerous to widespread showers and
scattered thunderstorms. MVFR conditions have moved into western
rtes early this morning which is expected to spread across most
rtes this morning. Heavier downpours will develop this morning
which will bring periods reduced visibilities to IFR and the
heaviest showers could have wind gusts to 30 kt otherwise winds
are expected to be light except for this afternoon when gusts to
20 kt will occur. MVFR/IFR conditions are expected to prevail
tonight as well.

LONG TERM /Friday through Monday/...
As of 330 AM Thursday...
For Friday and Saturday expect periods of sub VFR conditions as
heavy rain is expected across eastern NC. Precipitation will
affect ceilings and visibilities during the heaviest rainfall
and overnight periods. Rain is expected to continue through
Saturday and possibly into Sunday before tapering off early next
week. Thunderstorms are also possible during this time,
particularly in the afternoons but severe weather is unlikely.
Winds will keep a southerly component at 5-10 knots gusting to
15 kts.

&&

.MARINE...
SHORT TERM /Through Tonight/...
As of 430 AM Thursday...A prolonged period of low end SCA
conditions will develop today and continue through tonight.

Currently seeing southerly winds around 10-20 kt with seas
around 3-4 ft. A cold front will move into the coastal plain
today and stall and will see gradients tighten a bit allowing
winds to increase to around 15-25 kt this afternoon and continue
through tonight, with the strongest winds expected after
midnight tonight. Seas build to around 4-6 ft this afternoon and
to 5-7 ft tonight with some 8 ft seas possible across outer
portions of the waters.

Have issued a SCA for all waters but Albemarle Sound and
Alligator River as gradients will be weaker here. Most of the
waters begin SCA conditions early this afternoon except the
inland rivers which is expect to see SCA conditions develop
around midnight with frequent gusts to around 25 kt.

LONG TERM /Friday through Monday/...
As of 330 AM Thursday...Small craft conditions will likely
continue across the central and southern waters through Saturday
afternoon with wind gusts approaching 25 kts and seas near 6
ft. For Pamlico Sound, expect SCA conditions to relent Saturday
morning. Waves and winds will relax for Sunday and into the
middle part of next week.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Beach Hazards Statement until 8 PM EDT this evening for NCZ195-
     196-199-204-205.
MARINE...Small Craft Advisory until 6 PM EDT Saturday for AMZ135-152-
     154-156-158.
     Small Craft Advisory from midnight tonight to 6 PM EDT Friday
     for AMZ136-137.
     Small Craft Advisory until 6 PM EDT Saturday for AMZ150.
     Small Craft Advisory until 8 PM EDT Friday for AMZ231.

&&

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