-- Discussion containing changed information from previous version are highlighted. --
172
FXUS62 KMHX 270907
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
507 AM EDT Mon May 27 2024

.SYNOPSIS...
A cold front will then move through tonight or Tuesday.
The next front passes late Wednesday night or early Thursday
morning.

&&

.NEAR TERM /MEMORIAL DAY/...
As of 230 AM Monday...

 - Severe thunderstorm risk through the day (higher end risk
   possible)

 - Elevated heat risk this afternoon

A complicated forecast is on the table today, with a
conditional higher end severe weather potential apparent.

Early this morning, a decaying MCS is moving off the coast of
ENC, with a decreasing risk of gusty winds along its path. In
the wake of the MCS, an outflow boundary has been laid out that
extends back to the west into the Carolinas. Because of the
background southwesterly flow aloft, this boundary has already
begun to lift back to the north as a warm front in response to
an approaching upper level trough that is currently moving
through the Ohio Valley.

WAA-driven, elevated convection has recently developed along
the above-mentioned boundary across central NC. This convection
is located on the nose of an area of enhanced elevated moisture
transport that has developed across the Carolinas. Despite the
more worked over airmass downstream to the east of this
convection, I expect some maintenance into eastern or
northeastern NC through sunrise thanks to the strong moisture
transport helping support renewed elevated instability.
Sufficient instability, shear, and steep mid-level lapse rates
may allow a low-end hail risk to develop with these storms early
this morning if they survive into ENC.

Attention then turns to the west where a much larger MCS is
ongoing across the TN/OH Valleys at this time. The general trend
in recent guidance is that this MCS will weaken as it crosses
the Southern Appalachians this morning. Outflow from this
convection, or some remnant MCV, may then trigger renewed deep
convection downstream across central/eastern NC where sufficient
airmass recovery is expected in the wake of this morning`s
convection. Within that airmass, dewpoints rising into the low-
mid 70s beneath steep lapse rates will support the potential of
moderate to strong instability (MLCAPE on the order of
2000-3000j/kg). This will occur in the presence of 35-45kt deep
layer shear, which will be more than supportive of organized,
severe convection. With warm temps aloft, and some impact from
morning convection, it`s expected that a seasonably modest cap
will be in place. The challenge, then, is where/if convection
will redevelop during the peak overlap in shear and instability.
If so, the above mentioned shear/instability combo is
supportive of higher-end severe weather (golf ball, or larger,
hail, tornadoes, and 60-70 mph wind gusts). This is one of those
scenarios where messaging the potential of the environment is
important, while also noting that there are failure modes (ie.
less forcing, stronger cap, etc.) that could lower the severe
weather risk. Please stay tuned for updates throughout the day
as we assess the ever-evolving airmass.

Thunderstorms aside, hot temperatures and dewpoints in the 70s
will lead to an elevated heat risk, with a "feels like"
temperature closer to 100 degrees inland.

&&

.SHORT TERM /TONIGHT/...
As of 230 AM Monday...

 - Continued strong/severe thunderstorm potential overnight

An unstable airmass will remain in place through the night as
we remain in a southwesterly flow regime aloft. It`s unclear how
much convection will be ongoing through the night, as any
daytime convection will likely play an important role in where
storms exist through the night. However, barring widespread
convection during the day today, there should still be a risk of
strong to severe thunderstorms overnight ahead of a cold front
approaching from the west. Stay tuned for updates on this risk
through the night. Otherwise, it will be a very mild night.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
As of 0400 Monday...Long term opens up with showers associated
with lingering front Tues and then clearing through the week as
cool high pressure builds in.

Tuesday...Cold front lingers near the coast through the day Tues
as the base of the upper trough approaches from the NW. Showers
confined to the coast early Tues with chances increasing toward
the HWY17 corridor in the afternoon as seabreeze inches inland.
PoPs decrease from W to E behind the front which is expected to
fully push offshore through the evening, briefly turning winds
more Nerly. MaxTs in upper 80s most, upper 70s to low 80s
beaches.

Rest of Workweek...Upper trough persists with shortwaves
passing through the base of the trough Wednesday and again on
Thursday with weak SFC trough developing inland behind the
front. This troughing inland will delay the arrival of the SFC
high from the NW, keeping temps fairly warm Wed. Temps cool end
of the week as the high pressure begins spilling over the area,
MaxTs in upper 70s, MinTs in the 50s. Forecast remains dry
through this period.


Weekend...Upper trough swings through the East Coast and
offshore with SFC almost directly overhead Saturday morning
pushing offshore through the weekend. Get back to warm Serly
flow regime early next week ahead of the next front.
-- End Changed Discussion --


&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
SHORT TERM /through 06z Tuesday/...
As of 115 AM Monday...

 - Multiple rounds of TSRA possible over the next 24 hrs

A cluster of TSRA is moving through Eastern NC at this time
with gusty winds to 40kt. Occasionally, there have been a few
stronger cores with higher gusts (potentially as high as 50kt).
A general weakening trend is expected over the next 1-3 hours.
Attention then turns to another cluster of TSRA back to the west
in the TN Valley, and whether or not that will hold together to
the coast. If so, there would be another risk of strong wind
gusts of 40kt+. Another scenario is that those TSRA weaken as
they cross the southern Appalachians, with additional TSRA
developing from the SW, moving NE across the area. Stay tuned
for updates through Monday evening. It should be noted that in
the 2nd scenario mentioned above, there would be a greater risk
for 50kt+ wind gusts, hail, and maybe even a tornado. Where TSRA
occur, there will also be an increased risk of sub-VFR
conditions.

LONG TERM /Tuesday through Friday/...
As of 400 AM Monday...Showers and thunderstorms are expected
possible Tues with a drying trend setting up for the remainder
of the workweek. Periods of sub- VFR conditions are possible
but flight cats expected to remain VFR outside of convection.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
SHORT TERM /through tonight/...
As of 230 AM Monday...

 - Elevated winds and seas this afternoon into tonight

 - Increased thunderstorm risk through tonight

Southerly flow will steadily increase through the day, peaking
this afternoon and this evening at 15-25kt. Confidence remains
high enough to continue with a SCA to cover the 25kt and 5-6ft
seas potential. Additionally, confidence has increased in 25kt
winds occurring for a time across all waters, so with this
update I`ve added the Neuse, Bay, Pungo, and Pamlico Rivers to
the SCA. As a cold front approaches tonight, the gradient may
relax enough to keep the winds below 25kt overnight, but we`ll
continue to re- evaluate this potential and adjust the SCA
headline as necessary. Early this morning, a decaying cluster of
thunderstorms will move away from the coast. Another round, or
two, of thunderstorms is then possible through tonight. Where
thunderstorms occur, there is the potential for 40-50kt gusts,
hail, and waterspouts.

LONG TERM /Tuesday through Friday/...
As of 0400 Monday...A front lingers near the coast through the
day Tuesday before finally pushing offshore overnight/early Wed.
Showers and tstorms possible. SWerly winds 10-15G20kt. Winds
briefly turn Nerly behind the front early Wed before becoming
SWerly again as SFC trough approaches and moves through Wed
night, turning winds Nerly for the remainder of the work week.
Seas generally falling through the week; 2-4ft Tues, 2-3ft Wed,
1-3ft late week.
-- End Changed Discussion --


&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...Small Craft Advisory from 3 PM this afternoon to midnight EDT
     tonight for AMZ131-136-137-230-231.
     Small Craft Advisory from 3 PM this afternoon to 4 AM EDT
     Tuesday for AMZ135-150.
     Small Craft Advisory from 3 PM this afternoon to 6 AM EDT
     Tuesday for AMZ152-154-156-158.

&&

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