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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 241716
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
115 PM EDT Sun Mar 24 2019

.SYNOPSIS...
High pressure will move east across the region through Monday.
A cold front will move into the area Monday night and off the
coast Tuesday. The front will be accompanied by a period of
unsettled weather. Another cool area of high pressure will
dominate the weather for much of the upcoming week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 945 AM Sunday...Period of benign weather will continue
through the near term period. High pressure is centered across
northeastern NC this morning and it will continue to move off
to the east through tonight. Water vapor imagery shows mid/upper
low moving into southwest IA and northwest MO with weak ridging
aloft across the southeastern United States. The generally west
to east flow into the region will primarily act to spread some
thin high clouds across the area. Near full insolation will
support afternoon highs a category or so above normal. However,
cool SSTs and inland heating should cause enough of difference
to allow a sea breeze to develop. The resulting light onshore
wind will keep afternoon highs much cooler at the beaches. Very
light return flow will cause tonight`s lows to be much higher
compared to early this morning.


&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 3 AM Sunday...Strong warm advection Mon will push temps well
above climo and may lead to some isolated low-level convergence
showers developing in the morning, especially near the NC coast.
Rainfall chances ramp up after midday as surface based instability
increases and heights fall ahead of shortwave rotating through the
broad 5h trough. Shortwave helps induce weak low along slow moving
front, with both features moving into and across the area late Mon
night. The low and the front start getting ahead of the shortwave by
the time they reach the area, which may lead to weakening of
convection as it moves across the forecast area. In fact it looks
like the strongest PVA won`t arrive until after the surface low and
front move offshore. Still plan to carry likely pop but not quite
sold on categorical at this point. Clouds and moisture linger
through Mon night with light rain/drizzle continuing until almost
daybreak before surface and mid-level subsidence start to dry things
out. Despite cold advection starting Mon night, lows will still end
up well above climo.

Cold advection continues Tue and Tue night with Canadian high
building in from the north as another sharp shortwave passes
southwest of the area. There may be a brief reprieve Tue afternoon
with heating helping to offset cooling. Precipitable water drops
from around 0.75" Tue morning to 0.15" Wed morning, suggesting very
little in the way of cloud cover from midday Tue on. Temperatures
Tue and Tue night will be well below climo with potential for temps
near freezing late Tue night. Wind speeds should remain in the 5 to
10 mph range, negating most of the radiational cooling impact.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 3 AM Sunday...Mid-level pattern will transition from troughing
at the start of the period to weak shortwave ridging by the weekend.
Another shortwave digging over the Southeast helps develop 5h low
off the FL coast Wed into Wed night. This feature will be slow to
move away from the Southeast coast, but will remain too far offshore
to have any direct impact on the region.

-Main concern during the period will be potential for freezing
 temps Wed night. However, winds overnight will be 4 to 8 mph.

-Temperatures well below climo early in the period will trend
 upward as air mass modifies with above climo temps by the
 weekend.

&&

.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
As of 17Z...VFR throughout the period as high pressure continues to
drift to the east bringing southerly winds around 10 knots with a
few gusts near 15-20 knots. Overnight, increased moisture from the
south will help to develop mid-level clouds before the end of the
period. There could also be some areas of fog due to increasing low-
level moisture, however, confidence is low at the moment.

Extended Outlook...VFR conditions into Monday. Monday night, a cold
front will move over the area creating possible MVFR conditions. VFR
Tue evening through the rest of the week.

&&

.MARINE...
As of 945 AM Sunday...Light and variable winds with seas 2 ft or
less noted in the latest marine observations. High pressure is
centered across northeastern NC this morning and it will shift
offshore through tonight. The wind will turn to a southerly direction
as the high migrates toward the east and the sea breeze will aid
in some veering as well initially across the near shore waters. No
major changes with seas around 2 ft through tonight given the weak
pressure gradient. Confidence is increasing that some sea
fog is possible during the early morning hours Monday, but still not
confident enough to include in the forecast.

Southwest flow will increase during Mon as gradient becomes more
defined with speeds a solid 15 kt in the afternoon. Seas build from 2
ft Mon morning to 3 ft Mon night. Offshore flow develops late Mon
night as cold front moves east of the waters. Slowly developing low
along the front offshore combined with high building in from the
north will veer winds to north-northeast Tue and increase speeds to
20 to 25 kt Tue afternoon. Gradient remains pinched Wed and Wed
night with northeast flow 20 to 25 kt, and possibly higher at times,
into Thu before the high starts to weaken/retreat and gradient
relaxes. Extended period of strong northeast flow builds seas to 4
to 6 ft by Tue evening with seas peaking 4 to 8 ft Tue night through
Wed night. Although northeast flow starts to weaken on Thu,
prolonged nature of strong northeast flow will keep seas over 6 ft
through the end of the period.

&&

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

&&

$$

NEAR TERM...SRP
SHORT TERM...III
LONG TERM...III
AVIATION...21/SRP