855
FXUS62 KILM 202259
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
659 PM EDT Sat Jul 20 2024

.SYNOPSIS...
Seasonable temperatures and good chances for showers and
thunderstorms will continue for most of the next seven days as
Bermuda High offshore and the Piedmont Trough inland remain
nearly stationary.

&&

.UPDATE...
No big changes with the latest update other than for the 00Z
aviation forecast.

&&

.NEAR TERM /THROUGH SUNDAY/...
Not a lot of change to the overall pattern for the weekend with
Bermuda High and western Atlantic ridging aloft to the east and
broad 5h trough over the Mississippi Valley. The front will remain
stalled north and west of the area through Sun, keeping the warm and
very moist airmass in place. As has been the case the last few days,
convective initiation has been delayed with isolated storms just
starting to get going. Expect another round of convection moving in
from the southwest/west this evening as storms develop along the
front/Piedmont trough and then move east-northeast. On Sun
temperatures and storm development/coverage will be very similar to
Sat, given the similar environment.

Storms to develop will do so in a very moist environment. Deep
moisture, precipitable water over 2" and exceeding 2.25" at times,
coupled with a deep warm cloud layer will lead to elevated rainfall
rates. Heavy rainfall and slower moving storms, mainly on Sun when
storm motion will be around 10 kt, could lead to areas of localized
flooding. However, with the ongoing drought and only slight
improvement across the area from storms the last week or so, do not
expect to see any widespread flooding. An isolated strong/severe
storm is also possible purely based on SBCAPE around 2500 J/kg, but
overall potential remains low. Temperatures will be within a few
degrees of climo with lows running slightly above.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
Ridge of high pressure from the sfc up through the mid to upper
levels will remain to the east as piedmont trough and mid to
upper trough remain to the west and northwest. This will leave
the area in a deep persistent and moist southwest flow. Pcp
water values will remain very high, above 2.25 inches for the
most part. It will be subtleties in the position of the mid to
upper trough or ridge and Piedmont trough, sea breeze that
should make a difference in the timing and/or coverage of
storms, but overall, the tropical airmass will support shwrs and
tstms each day. As for the sea breeze on Sunday, it looks like
convection will only be isolated along it as it pushed inland.
But the sea breeze is really getting weaker this time of year as
waters grow warmer and not as great of differential heating. As
for later on Sun, models do show a shortwave riding by and
looks like it could produce more widespread or stronger
convection, especially over the Pee Dee and along Piedmont
trough inland. Temperatures will be in the 70s for lows tonight
and Sun night and hovering within a few degrees of 90 for
afternoon highs.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Ridge of high pressure from the sfc up through the mid to upper
levels will remain to the east as piedmont trough and mid to
upper trough remain to the west and northwest. This will leave
the area in a deep persistent and moist southwest flow. Pcp
water values will remain very high, above 2.25 inches for the
most part. It will be subtleties in the position of the mid to
upper trough or ridge and Piedmont trough, sea breeze that
should make a difference in the timing and/or coverage of
storms, but overall, the tropical airmass will support shwrs and
tstms each day. Overall, a persistence forecast with temps
hovering within a few degrees of 90 for highs and 70s for lows at
night. May see Tues or Wed flirt with Heat Advisory thresholds
depending on cloud and shower coverage.

Monday looks like ridge builds in from the east and best
shortwave energy should remain west and therefore should see
less coverage of shwrs/tstms. Ridge builds westward a bit more
into midweek with heights reaching up near 596 dm, but the SW
flow will continue to pose a challenge in terms of any shortwave
energy enhancing convection each day. Also see some moisture
flow from the Atlantic. As mentioned before, will have to see
how these features migrate each day. By late week, the ridge
gets suppressed a little more south and may see trough and
front/Piedmont trough moving south and east with greater
convective coverage over the area, especially toward the coast.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Moderate confidence for the 00Z TAFs across SE NC and NE SC.
Expect decent coverage of showers and a few storms into this
evening as instability, convective outflows and the sea breeze
peak, and energy aloft approaches from the southwest. Should be
drier the second half of the night with some stratus possible
late, especially inland where rain recently fell, which could
linger a bit beyond daybreak. Fog is also possible but less
likely given decent low- level winds off the surface. Expect
another round of showers/storms Sunday afternoon.

Extended Outlook...High potential for IFR/MVFR with showers and
thunderstorms each day through Thursday.

&&

.MARINE...
Through Sunday...Same setup, different days. Inland trough and
offshore high will maintain southwest flow at 10-15 kt through
Sun. Gradient has relaxed slightly, with the sea breeze being
the main driver of marginally higher winds near shore. Seas 2-3
ft with occasional 4 ft well away from shore continuing. Seas
will be a mix of a southerly wind wave and a southeast swell
with the wind wave barely dominant at times.

Sunday night through Wednesday...
Persistent southerly flow through Wed around Bermuda High.
Winds should back a bit more S-SE during the afternoon and a
bit more SW-W at night with land/sea breeze fluctuations,
especially near shore. Overall, winds 10 to 15 kts becoming a
bit higher and gustier in the afternoon sea breeze. Seas will be
in the 2 to 4 ft range with a longer period SE swell around 8
to 9 seconds mixing in.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
NC...None.
SC...None.
MARINE...None.through late
afternoon, with storm coverage increasing in the evening as
convection moves in from the southwest and west. Potential for
MVFR/IFR ceilings and visibility overnight if there is
significant rainfall with late evening storms due to somewhat
weaker boundary layer winds (boundary layer overnight will be
similar in strength to winds last night).

&&

$$

SYNOPSIS...ILM
UPDATE...RJB
NEAR TERM...III
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...RJB
MARINE...III/RGZ/31