Area NWS Forecast Discussion
000
FXUS62 KILM 100759
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
359 AM EDT Fri Jul 10 2020

.SYNOPSIS...
Tropical Storm Fay will continue pushing N from the area today
before moving inland over the mid-Atlantic or northeast United
States late tonight or Saturday. A slow moving front will be near or
just west of the area Sunday into early next week. The front is
expected to dissipate by midweek, allowing offshore high pressure to
gradually retake control of local weather.

&&

.NEAR TERM /THROUGH SATURDAY/...
A trough will linger at the surface and aloft over the area through
Saturday, though the column will dry somewhat through the period. In
combination with warm temperatures, this should result in mainly
diurnally driven isolated to scattered showers and storms both days.
Maximums will reach the upper 80s to lower 90s today with lower to
middle 90s on tap for Saturday.  Combined with dewpoints in the low
to mid 70s, the result will be heat index values peaking around 100
degrees today and up to 104 degrees Saturday.  Lows tonight will
mainly be in the middle 70s.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
The bulk of the NWP guidance has the area fairly dry Sat night into
Sun as a slug of drier mean layer RH air moves over the area from
the west. That said, really hard to rule out diurnal convection with
offshore high pressure/inland front pattern expected and have kept
in 20-30 percent PoPs as a result. Slightly higher precip chance are
advertised for Monday, as an upper trough axis and associated short
wave activity tied to a system moving through the Great Lakes
approach from the west. Better instability also expected on Mon,
which should also help yield a little more coverage of
showers/tstms. Temps in the short term expected to be a few degrees
above normal, mostly in the low to mid 90s for highs and lows mid
70s except upper 70s coast. Heat index values will reach upper 90s
to low 100s for a few hours both Sun and Mon, but expected to be
below advisory criteria at this time.

Another thing we`ll need to watch for is an increasing rip current
threat through the period, as a long fetch of 15-25kt S winds
develops off the SE US and Florida coasts between offshore high
pressure, allowing SSE swell to come up along area beaches.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
H5 trough axis will slowly slide offshore through Tue and Tue
night, with ridging eventually taking over the mid/upper pattern
as we move into the second part of the week. At the surface,
the front/troughing just inland from the coast early in the long
term will get taken over by offshore high pressure later in the
week. This pattern will gradually limit convection potential as
we move through the middle and back half of the workweek. Some
potential for below climo coverage with this pattern and have
made a slight trend in that direction based on latest guidance,
but not enough confidence to go much below low chance PoPs at
this time. Current forecast has heat indices below advisory
criteria each day of the long term, but will need to watch as
the deep layered ridging builds. The rip current threat
mentioned in the Short Term section is anticipated to continue
into midweek before easing late week as the ridging takes
control and swell subsides to more typical summertime values.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
MVFR stratus could develop late tonight, with the largest potential
for impacts at ILM after 08Z. After daybreak sunshine should push
the convective cloud base to 4000-5000 feet. Isolated showers or t-
storms are expected during the afternoon with best chances near the
coast.

Extended Outlook...Low pressure will exit the area Friday.
Diurnal convection will continue, especially near the coast,
with brief MVFR to IFR conditions expected through the weekend.


&&

.MARINE...
Expect NW winds of 10 KT or less to become SW tonight into Saturday
with an increase to 10 to 15 KT on tap for Saturday.  Seas of 2 to 3
feet today and tonight will build to 3 to 4 feet Saturday.

Some potential for Small Craft Advisory criteria to be met,
mainly in seas, Sun night into Mon as a long fetch of 15-25kt S
winds develops off the SE US Coast. Best chance for advisory
criteria being met is off our NC waters, esp. SE of Cape Fear. This
is in response to offshore high pressure interacting with a slow
moving front just to our west. Associated 6-8s SSE swell will come
down to the 3-4ft range into Tue. Winds will also trend more Wly
around 10kts as weak front/trough drifts towards the coast in the
morning, before trending to a sea breeze in the afternoon. Expect a
period of decent boating conditions mid to late next week as high
pressure impacts the area, with a couple of days with winds/seas
mostly below 15kt/3ft possible.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...None.
MARINE...None.

&&

$$
SYNOPSIS...MCW
NEAR TERM...31
SHORT TERM...MCW
LONG TERM...MCW
AVIATION...TRA/31
MARINE...MCW

NWS ILM Office Area Forecast Discussion