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517
FXUS62 KILM 201945
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
345 PM EDT Tue Aug 20 2019

.SYNOPSIS...
Bermuda High and Piedmont trough setup will continue through
Friday with scattered showers and thunderstorms possible each
afternoon and evening. A cold front move into the area Friday
night, stalling in the area into next week. Showers and
thunderstorms this weekend will continue into next week.

&&

.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
Typical summer-time conditions over the near term period, with
isolated to widely scattered aftn/evening shras/tstms and near
normal temps. An area of rain currently tracking through the mid
section of the fa will move off to the NE over the next few hours,
but coverage is quite limited attm, with the bulk of the activity
expected to stay west of the fa closer to an upper-level low.
Chances of rain diminish later this evening, with a slight uptick of
PoPs then for Wednesday morning as a mid-level vort max nears the
region. Low temps tonight range through the 70s.

A Piedmont trough and weakly forcing environment again then for
Wednesday, with PoPs capped at 35% all areas. No severe weather or
flooding anticipated. High temps in the upr 80s to lwr 90s. Typical
nocturnal decrease of precip then into Wednesday night, with low
temps again in the 70s.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Weakening mid-level ridge over the western Atlantic and Bermuda High
will maintain deep west-southwest flow which will continue pumping
Gulf moisture into the region. Deep moisture, diurnal instability
and the Piedmont trough/sea breeze will produce afternoon/evening
convection each day. Not a lot of mid-level support as far as any
impressive shortwaves go, but cannot rule out some brief enhancement
from passage of a weak feature. However, timing and picking out
these features is difficult at best. Convection coverage increases
Fri as Piedmont trough is pushed to the coast by approaching cold
front. Front slowly moves into the area Fri night which may keep
convection going all night. Coverage and intensity is likely to
decrease a bit, but high chance pop at minimum is likely warranted.
High will be near to slightly above climo with lows running above
climo.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Front moving into the area Fri night ends up stalling in the area on
Sat. Guidance is hinting that the front could push south Sun into
Mon, but also shows mid-level ridging to the west and over the
Bahamas. The mid-level pattern coupled with weak high pressure over
the Northeast suggests the front may end up lingering in the area
into next week. Thus confidence beyond Sun is rather low.

-Stalled front will support multiple rounds of showers and
 thunderstorms Sat and Sun.

-Potential for extended periods of heavy rain leading to
 isolated urban flooding over the weekend.

-Low confidence early next week with potential for good
 coverage of storms Mon and Tue.

-Highs several degrees below climo this weekend moving closer to
 climo Mon and Tue. Lows near climo through Tue.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
Predominantly VFR with high pressure center to our east. Scattered
to broken high clouds throughout TAF period being advected from the
SW, with scattered cumulus clouds in the afternoons and possibly
overnight at inland sites. Isolated storms this afternoon and
evening, mainly inland and along sea breeze boundary. Shortwave
to our SW will move NW of the area tonight into tomorrow
morning, and so there is a slight chance of showers, mainly
inland, after midnight. Cloud cover and elevated boundary layer
winds overnight should hinder fog development, despite adequate
low level moisture. South-southwest winds between 5 and 10 kts
during daytime hours, and around 3 kts overnight.

Extended...Mainly VFR thru Thu with brief MVFR/IFR periods each
day due to aftn/evening convection and fog and/or stratus
around daybreak. A cold front will drop south and stall across
the region Fri thru Sat. This will lead to an increase in tsra
coverage with MVFR/IFR conditions possible at any time of the
day or night.

&&

.MARINE...
Sub-Small Craft Advisory conditions continue through mid week with
high pressure offshore and a typical Piedmont trough inland. Expect
S/SW winds of 10-15 kt, except 15-20 kt winds Wednesday evening as
the pressure gradient tightens up a bit. Seas 2-3 ft through
Wednesday, then 3-4 ft for Wednesday night. This will mainly consist
of a 4 second S/SW 2-3 ft wind wave and a 10 second SE 1-2 ft
swell.

Bermuda High will linger off the coast into Sat, maintaining 10
to 15 kt southwest flow. Speeds will be highest in the
afternoon and evening. A slow moving cold front drops into the
area early Sat before stalling in the region through the
weekend. Speeds drop below 10 kt Sat and remain under 10 kt into
Sun morning with highly variable direction. Mixed signals for
Sun, right now forecast has northeast flow around 10 kt
developing, but this assumes the front pushes south of the
waters. The front could end up lingering in the area into the
middle of next week. If this happens, winds Sun would be lighter
with highly variable direction. Seas 3 to 4 ft Thu and Fri drop
to 2 ft or less over the weekend as winds drop below 10 kt.
South to southwest wind wave around 5 seconds will be the
dominant feature but some weak southeast swell around 10 seconds
will also be present.

&&

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

&&

$$

NEAR TERM...MAS
SHORT TERM...III
LONG TERM...III
AVIATION...VAO
MARINE...III/MAS