773
FXUS62 KMHX 260834
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
434 AM EDT Sun May 26 2024

.SYNOPSIS...
A warm front will move northeast through the area tonight. A
cold front will then move through Monday night or Tuesday.
Conditions dry slightly Tuesday and Wednesday before the next
front passes late Wednesday night/early Thursday morning. Cooler
temps and lower dew points follow in its wake.

&&

.NEAR TERM /TODAY/...
As of 215 AM Sunday...

 - Morning fog risk along the Outer Banks

 - Above normal temperatures this afternoon

 - Isolated strong to severe thunderstorm risk this afternoon

A subtle shortwave trough will move offshore early this
morning, with shortwave ridging briefly building overhead this
afternoon. At the surface, the only real feature of interest
will be the development, and inland progression, of the daily
seabreeze. Prior to the development of the seabreeze, a light
onshore flow across the Outer Banks may support a risk of low
clouds and fog, although recent obs, satellite imagery, and
webcams aren`t as supportive. For now, we`ll continue to
advertise reduced visibility and fog early this morning, but may
need to pull back on this if current trends hold.

Moving into the afternoon, the background southerly low-level
flow should encourage a more progressive seabreeze, with weaker
convergence along it. The lack of stronger convergence, plus
shortwave ridging overhead should keep afternoon seabreeze
convection at a minimum (10-20% chance). Where/if convection can
form, and be sustained, moderate instability (MLCAPE around
2000 j/kg) and 20-25kt of deep layer shear will be supportive of
a pulse severe thunderstorm risk (mainly a wind and hail risk).

With the expectation of less cloudcover, and a lower coverage
of thunderstorms, strong heating and warm low-level thicknesses
should support another afternoon of above normal temps (highs
near 90 inland, and low 80s for most beaches). The exception
will be the northern Outer Banks where highs may struggle to get
above the mid 70s thanks to the cooler onshore flow.

&&

.SHORT TERM /TONIGHT/...
As of 215 AM Sunday...

 - Watching evening/overnight thunderstorm risk

 - Near record warm lows tonight

Shortwave ridging will shift offshore tonight, allowing
southwesterly flow aloft to develop ahead of a potent upper
level trough approaching from the west. Within the developing
southwesterly flow, an impressive EML plume is forecast to
translate NE across the Southeast US. On the nose of that plume,
a few elevated thunderstorms may attempt to develop during the
evening hours across central/eastern NC. Separately, convection
is expected to be ongoing upstream from the TN/OH Valleys into
the southern Appalachians. We`ll have to keep an eye on how this
convection progresses through the night, as there is some
potential for a cluster, or two, of thunderstorms to make a run
at Eastern NC late in the evening or during the overnight hours.
There is also the potential that continued low-mid level
moistening could support scattered, elevated convection
developing that may not specifically be tied to any upstream
convection. Where/if convection can develop, the combination of
MUCAPE of 500-1000j/kg, steepening lapse rates, and modest shear
appears supportive of gusty winds and small hail. The risk of
severe weather tonight isn`t zero, but appears to be LOW (<10%
chance for the area at large). Stay tuned for updates through
the night, though, in case this risk were to increase.

Thunderstorms aside, increasing southerly flow and increasing
cloudcover is expected to support well above normal lows, with
near- record warm lows expected.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
As of 400 AM Sunday...A complex upper-level pattern will keep
the beginning of the long term busy. On Monday, an upper-level
ridge over the eastern seaboard will be pushed offshore as a
double-barrel low spins over the Great Lakes region. This pair
of low pressure systems will send multiple lobes of energy
around the base of the trough for the next several days.

Memorial Day...There will be two weather concerns on this holiday:
heat risk and severe weather. Healthy southerly low-level flow will
send temps into the low 90s and dew points into the mid-70s across
the coastal plain. This will create "feels like" temperatures of 95-
100 for most areas away from the beaches. With a passing shortwave
aloft and the incoming cold front, there will be scattered shower
and thunderstorm activity through the day with chances peaking
during the evening hours (overnight for beaches). Wherever scattered
storms develop, they will have an incredibly impressive environment
to work with in the form of 2000-3000 J/kg MLCAPE, 40-45 kt deep
layer shear, 200-300 m2/s2 0-3 KM SRH, 8-8.5 C/km mid-level lapse
rates, and PWATs 1.5-2". This puts all hazards on the table
(damaging wind gusts, large hail, and tornadoes). Limiting factors
for strong to severe development will be modest forcing (prior to
the front) and a capping inversion. SPC currently has our area
outlined in a Marginal Risk (1/5) with a Slight Risk (2/5) just to
our north.

Tuesday-Wednesday...PoPs decrease from west to east on Tuesday as we
settle into the slightly cooler and drier post-frontal air mass.
Temps will reach the mid- to upper-80s both days with afternoon dew
points in the refreshing mid-50s by Wednesday.

Thursday-Sunday...The next cold front is set to pass late
Wednesday/early Thursday. This will bring in a cooler air mass and
limit highs each day to the low- to mid-80s across the coastal
plain. The beaches will hang back in the 70s. The forecast remains
dry until the end of the weekend when the next potent shortwave
introduces slight chance (20-25%) PoPs across the area. It should be
noted, however, that other shortwaves will be embedded within the
flow prior to the one on Sunday, and it`s possible that PoPs trend
up.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /through 06z Monday/...
As of 145 AM Sunday...

 - BR/MIFG possible overnight (40-60% chance)

 - Seabreeze TSRA possible Sunday (10-20% chance)

Clearing skies, light winds, and a moist boundary layer will
support a chance of reduced VIS overnight due to BR/MIFG. While
LIFR conditions are not off the table, guidance suggests a low
probability of this occurring across most of Eastern NC. The one
exception is along the Outer Banks where there continues to be
a fairly solid signal for LIFR conditions at times. Of note,
though, short-term guidance appears to be overly aggressive when
compared to current obs and satellite imagery in that area.
This gives me pause on whether or not widespread low CIGs/VIS
will occur there. Otherwise, away from the Outer Banks, I`ve
leaned more towards TEMPO groups for the potential sub-VFR
conditions.

Outside of the Outer Banks, any reduced VIS should quickly
improve around sunrise Sunday. During the afternoon hours, a
weak seabreeze is expected to develop and shift inland,
potentially accompanied by a low-end chance of SHRA and TSRA. To
avoid flip-flopping, I left a VCSH mention in from the previous
TAFs, but it appears the risk of SHRA or TSRA at any one TAF
site will be low (<20% chance).

LONG TERM /Monday through Thursday/...
As of 400 AM Sunday...Showers and thunderstorms are expected
Monday with a drying trend setting up after that. Periods of
sub-VFR conditions are to be expected but flight cats should
remain VFR outside of convection.

&&

.MARINE...
SHORT TERM /through tonight/...
As of 300 AM Sunday...

 - Dense fog potential this morning

 - Great boating conditions this afternoon

Light winds of 5-10kt, and limited long-period swell, will
continue to support seas of around 1-2 ft through early this
evening, making for great boating conditions for most waters.
The one exception will be the northern rivers/sounds/coastal
waters where dense fog will impact navigation this morning. It`s
unclear how long the fog will last, and how widespread it will
be, but the latest expectation is for it to be an impact through
at least mid-morning. While the risk may not be as high as
previously thought, we`ll allow the Marine Dense Fog Advisory to
continue for now, as there are some recent indications that fog
may soon develop in this area. By tonight, a modest increase in
southerly winds should help keep the fog risk lower. This
increase will also lead to seas slowly building to 2-3 ft
through the night. For now, most waters are expected to be
thunderstorm-free through this evening. Late tonight, the risk
of thunderstorms may increase some.

LONG TERM /Monday through Thursday/...
As of 4 AM Sunday...Conditions deteriorate Monday ahead of an
approaching cold front that will bring a risk of showers and
thunderstorms and the next best chance for a SCA. SW flow will
increase from 10-15G20 kt to 15-20G25 kt by Monday evening. Seas
will respond and build to 3-5 ft by Monday night. Conditions
improve Tuesday with SW flow returning to 10-15 kt and seas
decreasing to 2-4 ft. 10 kt winds wobble between northwesterly
and southwesterly on Wednesday. Another front late
Wednesday/early Thursday will turn 10 kt winds northwesterly by
morning and northeasterly by evening.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...Dense Fog Advisory until 10 AM EDT this morning for AMZ131-135-
     150-152-230-231.

&&

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