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000
FXUS62 KMHX 211748
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
148 PM EDT Sun Apr 21 2024

.SYNOPSIS...
An area of low pressure will move away from the coast by this
evening. High pressure briefly builds into the area early next
week followed by a cold front with limited moisture pushing
across the area Wednesday. High pressure builds back into the
area for the latter half of the work week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 115 PM Sunday...

Early afternoon SFC analysis reveals a ~1009mb surface low
southeast of Cape Lookout. A trailing cold front extends back to
the SW towards the coast of SC. Aloft, an upper level shortwave
is moving through central Georgia, with a zone of low-mid level
frontogenesis extending northeast through central SC/NC.

The shortwave will continue to lift northeast through this
evening, with low-mid level frontogenesis and modest jet exit
region dynamics interacting with a deep layer of moisture in
place. Despite the relative "lull" in rain right now, I expect a
more solid area of rain over GA/SC to overspread
central/eastern NC in a few hours, with precip lasting past
sunset. Guidance may be a little aggressive with ending the
precip this evening, so I slowed the departure a bit compared to
the previous forecast. Eventually, gradual drying aloft should
support a west to east decrease in the steadier precip. However,
with the main upper level trough axis still to the west, and
with lingering moisture, I`m not convinced yet that the rain
will end for the whole area, so I`ve continue to hold onto a
mention through the night, especially east of HWY 17.

&&

.SHORT TERM /MONDAY/...
As of 115 PM Sunday...

An upper level trough will pivot east through the Carolinas on
Monday. At the surface, low pressure off the coast will deepen
thanks to increasing height falls aloft. While the pressure
gradient will relax some tonight, the deepening low will act to
increase the gradient for a time on Monday, with a bit of an
uptick in northerly winds expected. 12z model guidance has
trended up with winds on Monday, especially along the coast, and
I reflected this trend in the forecast.

Regarding precip, the better, and deeper, moisture is forecast
to shift offshore on Monday, but until the upper low clears the
coast, I expect at least a low-end chance (20-30%) of showers to
continue, especially along the coast. Temperatures on Monday
are expected to be well below normal for late-April, especially
where clouds linger the longest. Along the coast, highs will
struggle to get out of the 50s. Inland, some breaks in the
clouds may allow highs to get into the low 60s, but this will
still be 10-15 degrees below normal.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
As of 415 AM Sunday...Fairly quiet stretch in the long term
with high pressure dominating early in the week, mostly dry
front moving through mid-week, and another high pressure setting
up to our and north through the weekend.

Tuesday...Clear skies and calm winds bring bring lows near 40
inland Tuesday morning. Along the coast lows are a bit higher,
in the low 50s, as the gradient is pinched a bit more there with
the high building from the west and and the low offshore to the
east. This might be enough to prevent true decoupling due to
radiational cooling. High pressure builds into the area Tuesday,
with highs near 60 inland, mid 60s for beaches.

Wednesday...Low sweeps to our north, pinching the pressure
gradient with the high to our south. This looks to prevent
decoupling Wednesday morning, leaving lows in the mid to upper
40s to start the day inland. Along the coast lows will be in the
mid 50s. High pressure moves offshore through the day Wednesday
with the help of a weak cold front associated with the sweeping
low. This will cause winds to veer from southerly to northerly
through the day. Atmospheric column looks to be fairly dry
during the weak cold front passage, preventing the inclusion of
mentionable PoPs for Wednesday. Wednesday looks to be the
gustiest day in the long term, with ample mixing allowing gusts
of 20kts inland. Fortunately RHs will be well above 35%, so fire
weather should not be a concern. Highs look to be in the mid to
upper 70s inland, near 70 for the coast, aided by the south
veering west flow through the day.

Thursday to Saturday...High pressure to our north keeps us dry,
with high temps incrementally increasing each day. Into the
weekend, omega block setup initiates at upper levels. This will
allow the high pressure to linger through the remainder of the
long term. Low moving through the eastern US in the weekend will
encounter this stubborn high, and some uncertainty remains on
if it will be pushed north around the high, or if the high will
give way. If the low moves north, we will have less chances of
precip in the weekend. If the low is able to shift the high
offshore, we will see increased chances of precip. Currently
have Schc PoPs for extreme western and northern portions of the
CWA Saturday PM to cover this.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM /through 18z Monday/...
As of 115 PM Sunday...

KEY MESSAGES

1) IFR conditions expected through late this evening

2) Widespread RA and MVFR VIS expected late this afternoon -
this evening

3) VFR conditions possible (40-60% chance) by Monday morning

FORECAST DETAILS

Low pressure, and an associated cold front, will move away from
the coast this afternoon, with widespread post-frontal low CIGs
and RA lasting into late this evening. Moisture and lift begin
to decrease after 06z tonight, and model guidance generally
agree on rising CIGs after that time. I`ve reflected this
expectation in the TAFs, but went slower than guidance with
improving conditions back to MVFR/VFR, as sometimes guidance can
be too quick to improve conditions in patterns like this.
Mostly VFR is expected on Monday, although a mix of VFR/MVFR
appears plausible along the coast, along with a continued risk
of SHRA.

LONG TERM /Monday night through Friday/...
As of 345 AM Sunday...Improving conditions will continue with
pred VFR through Thursday. Decoupling Monday night/Tuesday
morning inland could bring a fog threat, but too much
uncertainty exists for anything other a brief mention in this
AFD. Thursday could bring some lower cloud cover as low level
moisture increases a tad, but again, too much uncertainty on
cloud base height and coverage at this point.

&&

.MARINE...
SHORT TERM /Through Tonight/...
As of 1015 AM Sunday...

Low pressure is located about 60 miles SE of Cape Lookout, and
continues to lift ENE through the central/southern coastal
waters. The pressure gradient north of the low has tightened
quicker than forecast, and winds have responded faster. The SCAs
are all scheduled to start at the top of the hour, and given
recent trends in obs, this will work out nicely. With this
update, I bumped winds up a bit, especially for the northern
waters/rivers/sounds. This increases the risk of a few hours of
gales, but I still expect it to be short-lived, and will
continue with a strongly worded SCA.

PREVIOUS DISCUSSION...No changes to previous thinking. SCA`s
are now in effect for all of the waters as developing low
pressure tracks northeast just off of the coast today into
tonight. This will result in strong northerly flow developing
today and continuing into tonight. Winds this morning are
currently N to NE 5-15 kt and will increase to 15-25 kt by early
afternoon. Northerly flow will continue 15-25 kt tonight. 2-3
ft seas this morning will build to 5-7 ft this afternoon and 6-9
ft tonight.

LONG TERM /Monday through Thursday/...
As of 345 AM Sunday...As the coastal low strengthens offshore,
seas will be slow to drop below 6 ft for western portions of marine
zones, finally doing so on Tuesday. Seas remain 3-5 feet for
much of the coastal marine zones in the remainder of the long
term. Further offshore in western portions of the marine zones,
there will be multiple rounds of waves at 6-7 feet through the
long term. Winds will be below SCA criteria through the long
term.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Beach Hazards Statement until 8 PM EDT this evening for NCZ203-
     205.
MARINE...Small Craft Advisory until 8 PM EDT this evening for AMZ131-
     137-230-231.
     Small Craft Advisory until 8 AM EDT Monday for AMZ135-150.
     Small Craft Advisory until 6 PM EDT this evening for AMZ136.
     Small Craft Advisory until 11 AM EDT Tuesday for AMZ152-154.
     Small Craft Advisory until 5 AM EDT Tuesday for AMZ156-158.

&&

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