602
FXUS62 KMHX 261339
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
939 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 or early Thursday morning.
Cooler temps and lower dew points follow in its wake.

&&

.NEAR TERM /TODAY/...
As of 940 AM Sunday...

 - Morning fog risk along the Outer Banks

 - Above normal temperatures this afternoon

 - Isolated thunderstorm risk this afternoon

A subtle shortwave trough is moving offshore this morning, with
shortwave ridging briefly building overhead behind it. 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 will continue to support an area of low
clouds and patchy fog. Based on satellite and surface obs, it
appears the fog has mainly been confined to Dare County. Because
of the patchy nature, no land- based fog headlines are planned
for the rest of the morning.

Moving into the afternoon, the background southerly low-level
flow should encourage a more progressive seabreeze, but 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 scenario, with mainly a wind and
hail risk.

With the expectation of less cloud cover, 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 715 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 day and into tonight, 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. Of note, recent short-term guidance has trended
towards an increased risk of a dying MCS moving into Eastern NC
in the 10pm-1am timeframe, and pops have been adjusted up a bit
during this time. 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 (10-20% 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 /14Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /through 12z Monday/...
As of 715 AM Sunday...

 - TSRA risk this afternoon and tonight

Light winds this morning will gradually increase through the
morning, becoming southerly as the seabreeze develops and moves
inland. The seabreeze isn`t expected to be overly active today,
but a few TSRA will be possible (10-20% chance). By this
evening, and into tonight, we`ll be watching TSRA upstream
across western and central NC, as some of these storms may make
a run at Eastern NC between 01z-07z. If TSRA make it this far
east, there would be an increased risk of gusty/erratic winds to
40kt and small hail (up to half inch in diameter). Sub-VFR
conditions would be possible as well (mainly due to reduced
VIS).

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 940 AM Sunday...

 - Dense fog risk lingers this morning. Extended DFA north of
   Oregon Inlet and the northern sounds through noon.

 - Great boating conditions this afternoon

Light winds of 5-10kt, and weak 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 continue to impact navigation
through late morning and early afternoon. Based on webcams and
satellite imagery, it appears the greatest risk of dense fog
will be confined to a relatively small area of the eastern
Albemarle Sound, Croatan/Roanoke Sounds, and the nearshore
coastal waters from Duck to Oregon Inlet. 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, especially across the
southern rivers (New, Neuse, etc.) and the nearby coastal
waters.

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 noon EDT today for AMZ131-150-230-231.

&&

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