489
FXUS62 KMHX 271131
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
731 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 /TODAY/...
As of 645 AM Monday...

 - Severe thunderstorm risk through the day

 - Elevated heat risk this afternoon

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

The small MCS that moved through ENC last night has moved
offshore and weakened. In its wake, an outflow boundary has been
laid out that essentially stretches west to east along the
NC/SC state line, and is acting more like a warm front.
Meanwhile, an expansive MCS is ongoing from the central
Appalachians south through the Lower TN Valley. Increasing
southerly flow, and warm/moist advection ahead of the MCS,
appears to be supporting scattered elevated convection north of
the above-mentioned outflow boundary/warm front. As the
southerly flow strengthens, the outflow/warm front should lift
north, with the morning convection also lifting north into
Virginia. For the early morning update, I`ve pulled back some on
the chance of thunderstorms, especially just after sunrise, as
it now appears the best forcing will keep convection focused
just to our west/NW through at least mid-morning. There`s still
some potential, though, especially as WAA increases overhead.
Additionally, if any morning convection can become surface-
based, there would be a tendency to turn more right with time,
potentially glancing our area.

Attention then turns to the west where the ongoing, and
expansive, MCS is trekking east across the Appalachians. Recent
06z-09z short- term guidance remains mixed on how the ongoing
MCS will evolve as we move through the day. Warming cloudtops
across the northern end of the MCS is suggestive of a weakening
trend. However, the southern end of the MCS still appears very
healthy.

East of the MCS, short-term guidance is insistent on increasing
southerly flow leading to boundary layer recovery/moistening
beneath steep mid-level lapse rates through this evening,
supporting moderate to strong destabilization. SREF probability
guidance gives a 70% chance of MLCAPE exceeding 2000 j/kg, with
some deterministic guidance indicating values as high as 3000
j/kg. The magnitude of instability is noteworthy, especially in
tandem with 40-50kt of deep layer shear forecast. At face value,
this would be supportive of some higher-end severe weather
potential (ie. golf ball, or larger, hail and 60-70+ mph wind
gusts). That said, there are still some uncertainties with what
impact the upstream MCS, and any morning convection, will have.
We`ll continue to message the higher end potential, but also
continue to note that there is more uncertainty than normal.
Lastly, while the highest risk looks to be wind and hail. 0-1km
SRH is forecast to top out around 100-150 m2/s2 which would
support a tornado risk, especially where/if supercells develop.
This risk could be maximized along any residual boundaries
and/or the afternoon seabreeze. There appears to be a focused
area from the coastal plain northeast through the Albemarle
Sound vicinity where guidance is hinting at the greatest tornado
potential.

Stay tuned for updates through the day on this ever-evolving
situation.

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/...
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.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
SHORT TERM /through 12z Tuesday/...
As of 715 AM Monday...

 - Multiple rounds of TSRA possible over the next 24 hrs

SCT TSRA are ongoing just west of Eastern NC at this time, and
these are expected to remain just to our W/NW through the
morning hours. With this update, then, I`ll remove the VCTS
mention for the morning hours. Attention then turns to another
cluster of TSRA back to the west that is just now crossing the
Appalachians, and whether or not that will hold together to the
coast. If so, there would be another risk of strong wind gusts
of 40-50kt+. Another scenario is that those TSRA weaken as they
cross the Appalachians, with additional TSRA developing from the
SW, moving NE across the area later today into tonight. In that
scenario, there would be a higher risk of 50kt+ wind gusts,
large hail, and tornadoes. Sub-VFR conditions can be expected
where TSRA occur as well. Late tonight, an area of low CIGs may
develop in the wake of any TSRA activity.

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.

&&

.MARINE...
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. A round, or two, of thunderstorms is
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.

&&

.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