245
FXUS62 KMHX 190807
AFDMHX

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
407 AM EDT Wed Jun 19 2024

.SYNOPSIS...
High pressure dominates through Thursday resulting in dry and
warm conditions. Coastal troughing may bring some showers to
the region late in the week into the weekend. A steady increase
in heat and humidity is expected over the next several days with
"feels like" temperatures potentially reaching the triple digits
on Sunday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 4 AM Wednesday...Another day of pleasant weather is in
store as surface high pressure and the mid-upper ridge remain
dominant over ENC. Weak surface troughing will setup this
afternoon, which could support a few sprinkles, but chances are
low given the weak forcing and strong subsidence. Highs will max
out around 90 across the inner coastal plain with the coast and
OBX reaching the mid-upper 80s. With dew points in the low 60s,
minimum RHs will be around 35-40% (see Fire Weather section for
details).

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
As of 4 AM Wednesday...Mild overnight temps return ranging from
the low-mid 60s across the inner coastal plain to low 70s along
the OBX. Fog seems unlikely given greater cloud cover and
unlikelihood that we`ll reach crossover temps. Low stratus seems
more probable given our continued onshore flow and increase in
low- level moisture.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
As of 230 AM Wednesday...

 - Elevated fire weather concerns continue into this weekend

 - Building heat and humidity this weekend into early next week

 - Increased thunderstorm risk early next week

Synoptic Summary: Surface and upper level ridging are forecast to
remain in place through the end of the work week. Ridging then
begins to break down over the weekend and into next week as upper
level troughing develops from the Great Lakes into the Eastern U.S.

Thursday: A moist easterly flow and modest WAA may support a few
westward-moving coastal showers, especially Thursday morning
(similar to what has been observed early this morning). Rainfall
amounts look to be very light, but given a consistent signal in
deterministic guidance, I felt it worth a low-end chance mention
along the southern OBX/Crystal Coast area. Otherwise, Thursday
should be the last day of near normal temperatures thanks to lower
thicknesses in the continued easterly low-mid level flow.

Friday-Sunday: Medium range guidance continue to insist that the
upper level pattern will begin to change during this time. As upper
level ridging breaks down, and as the surface high shifts offshore,
a moistening return flow is forecast to develop. Within this flow,
low-level thicknesses will begin to increase as well. This will lead
to a steady increase in the heat and humidity, starting Friday,
and most likely peaking on Sunday. By Sunday, dewpoints in the
70 and highs in the 90s is expected to support "feels like"
temperatures rising into the 100-105 degree range. This has been
consistently supported by both deterministic and ensemble
guidance, and we`ll plan to begin messaging this impact in the
HWO and other public- facing products.

Despite increasing moisture, warm temps aloft will support a notable
cap through at least Saturday. This combined with limited forcing
should keep the risk of showers and thunderstorms at a minimum. Any
chance of showers should be confined to the daily seabreeze. On
Sunday, less of a cap is expected, and we should see a little more
activity on the seabreeze (but probably still isolated in coverage).

Lastly, a tightening pressure gradient within the developing lee-
trough will support increasing south to southwest winds by Sunday.
Ensemble guidance suggests dewpoints will mix out across the coastal
plain as the winds and mixing increase, and this seems reasonable
given the dry pattern of late, and very dry soils. With this in
mind, the overlap of lower RH and breezy conditions should support a
continued elevated fire weather risk.

Monday-Wednesday: Deterministic and ensemble guidance continue to
show a moderate to strong signal for deeper moisture reaching
Eastern NC within the continued southerly low-mid level flow. This
in tandem with the seabreeze, a glancing shortwave, and possibly a
cold front dropping into the area is expected to support an
increased thunderstorm risk, especially on Monday. The overlap of
moderate instability and modest deep layer shear could also support
a marginal severe thunderstorm risk.

Dewpoints are expected to peak during this time, with a subsequent
peak in humidity values. Afternoon highs are less certain, though,
due to the potential for increased convective activity. However,
given the boundary layer moisture in place, "feels like"
temperatures could make a run at 100+ where sufficient heating can
occur. Right now, Monday looks to carry the greatest risk of heat-
related impacts.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /through Wed/...
As of 1:20 AM Wednesday...High pressure remains in control but
low-level moisture advection is increasing cloud cover from east
to west. The possibility of this swath of stratus clouds
generating MVFR ceilings is low (10-20%). VFR conditions are
expected tomorrow with diurnal cu developing in the afternoon.
After the loss of peak heating, coverage will diminish to a few
high clouds as we head into the overnight hours.

LONG TERM /Wednesday night through Sunday/...
As of 230 AM Wednesday...

 - Sub VFR CIGs possible (40-60% chance) along the coast Thursday

 - Breezy southerly winds Sunday and Monday

 - Increased TSRA risk Monday

A moist easterly flow may continue to support isolated SHRA activity
along the coast on Thursday, along with SCT/BKN low CIGs. This
appears most likely along the coast, with less of a risk inland.
Drier air then works back in Friday into Saturday, with less of a
risk of SHRA or sub-VFR conditions. Breezy southerly winds are
likely Sunday into Monday (60-80% chance). Increasing moisture
within the southerly flow is also expected to lead to an increased
TSRA risk, especially by Monday.

&&

.MARINE...
SHORT TERM /through Wednesday/...
As of 4 AM Wednesday...Seas are building across the outer waters
due to the distant tropical wave and extended period of easterly
flow that we`ve been experiencing. The outer waters south of
Oregon Inlet are expected to build to 6 ft by this afternoon, so
a SCA has been issued for these zones through 11 PM tonight. The
wind field will remain easterly at 10-15 kt with gusts near 20
kt south of Cape Hatteras.

LONG TERM /Wednesday night through Sunday/...
As of 230 AM Wednesday...

 - Elevated wind and seas possible Sunday - Monday (40-60% chance)

 - Increased thunderstorm risk on Monday

Continued easterly flow is expected to continue to support seas of 4-
6 ft on Thursday. Seas then slowly lay down to 2-4 ft as we move
into the weekend thanks to a weakening of the easterly flow. Light
south winds of 5-15 kt Friday and Saturday increase to 15-25kt
Sunday into Monday, along with seas once again building to 4-6 ft. A
few showers will be possible on Thursday, and again on Monday. The
greatest risk of thunderstorms is expected Sunday night into
Monday.

&&

.FIRE WEATHER...
As of 4 AM Wed...The dry airmass remains in place with minimum
RHs around 35-40%, especially away from the coast. This will
overlap with breezy E winds at times, and is noteworthy for any
ongoing, or planned, fires.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...Small Craft Advisory from 3 PM this afternoon to 11 PM EDT
     Thursday for AMZ152-154-156-158.

&&

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