Area Forecast Discussion
Issued by NWS Wilmington, NC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KILM 252239
AFDILM

Area Forecast Discussion
National Weather Service Wilmington NC
638 PM EDT Wed Apr 25 2018

.SYNOPSIS...
A series of low pressure systems, will bring isolated showers this
afternoon, and then a better chance of rain with isolated storms
Thursday night. A drying trend is expected later in the weekend
through the first part of next week, with below normal temperatures,
as a Canadian High drops into the mid-Atlantic region. A warming
trend is expected by the middle of the week.

&&

.NEAR TERM /THROUGH THURSDAY/...
As of 325 PM Wednesday...Upper low rotating slowly across the Mid-
Atlantic is producing steep lapse rates which are working together
with highs in the 70s to produce instability and cu/showers. As is
typically the case beneath these upper low, Cu has been extensive
beneath the cold pool aloft, and showers/storms have developed.
However, despite SBCape of 500-1000 J/kg, storms have been displaced
north of the local area and even showers have struggled locally
thanks to very dry air above 700mb and some weak subsidence aloft as
well. Still carrying SCHC for NC zones through this evening, but any
activity will be light and diurnally forced, so a quiet night is
expected. As the upper low pulls away, it will drive a weak trough
across the area, causing winds to shift to the NW ahead of a ridge
of surface high pressure. At the same time, a secondary shortwave
will be digging into the Arklatex region, and 850-500mb moisture
begins to increase ahead of this feature. This will keep some mid-
level cloudiness around through the night, so despite light winds,
mins will stay elevated tonight falling into the upper 50s.

On Thursday, the aforementioned upper low approaches which causes
increasing diffluence, better column moisture, and an increasing
chance for showers through the day. Guidance is slow with the
surface reflection so expect only minimal shower chances through
Thursday, but have shown low-chc near i-95 by the end of the period.
Another seasonable day is forecast despite the clouds however, and
highs will climb into the mid 70s, near 70 at the beaches.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
As of 325 PM Wednesday...Closed 500 mb low and associated surface
low centered over southeast TN and northern GA Thursday evening will
open up and lift across the Mid-Atlantic states through Friday. A
warm front is expected to be just north of the forecast area at 00Z
Friday, with the cold front poised to enter the western zones around
midnight. Marginal instability in the warm sector will lead to
potential for isolated thunderstorms along with the scattered to
numerous showers ahead of the frontal boundary. By 12Z Friday, most
of the activity will be northeast of the area, however additional
light showers may develop later Friday in lingering moisture below
700 mb, ahead of an approaching 700 mb trough.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 325 PM Wednesday...The next shortwave is progged to primarily
pass south of the Carolinas during Saturday morning while the main
upper low translates across the eastern Great Lakes Region. Thus not
much in the way of lift for our part of the Carolinas and a rather
dry column through the extended supports very little in the way of
POPs. A dry frontal passage Saturday night will be followed by cool
high pressure at the surface through the remainder of the weekend.
Although temperatures will be cooler than normal Sunday and Monday
the weather will be quite tolerable with highs generally in the
lower 70s with clear skies. A warm-up is expected by mid-week as the
high moves off the coast with as return flow develops.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
As of 00Z...Clouds appear to be dissipating at this time, as these
waning clouds are the result of an upper low, cold air aloft, which
kicks off cumulus/stratocumulus in the afternoon. Upper low will
have less influence tomorrow, but still a VFR ceiling is possible.
Winds becoming light after 01Z, with a southeast gradient/resultant
in the afternoon on Thursday.

Extended outlook...Tempo MVFR Thu night through Sat. Otherwise
VFR.

&&

.MARINE...
NEAR TERM /THROUGH THURSDAY/...
As of 325 PM Wednesday...Small Craft Advisory for NC waters remains
in place through 8pm for residual 6 ft seas even as winds have
fallen well below criteria. Winds will continue to ease and shift to
the W/NW this evening as a trough moves overhead. This will push the
remaining 6 ft seas out of the 20nm boundary, and the SCA should
expire on time, if not be cancelled a bit early. Winds will become
W/NW around 5 kts overnight, and then veer slowly to the NE and then
E and finally the S on Thursday at around 10 kts in response to a
retreating surface high and approaching weak low. These winds will
keep seas at low amplitude, 2-4 ft.


SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
As of 325 PM Wednesday...Surface low pressure will move up the
Appalachians Friday, resulting in southerly flow across the
waters during the day. The magnitude of the gradient will remain
modest, with winds remaining 15 kts or less. Winds will veer to
the southwest during the evening with the approach of a cold
front, which will move off the coast after midnight Thursday
night. Not much of a wind shift will occur behind the front,
although it will be accompanied by scattered to numerous showers,
and isolated thunderstorms. Winds will become more westerly by
late Friday night as a weak surface trough approaches the coast
from the west.

LONG TERM /SATURDAY THROUGH MONDAY/...
As of 325 PM Wednesday...A front will shift off the coast
Saturday night followed by high pressure building in from the
northwest through Sunday night. The high will build over the waters
during Monday. Southwest winds ahead of the front Saturday will
veer to a westerly direction Saturday evening, then turn northerly
in the wake of the front by Sunday morning. Variable flow is
expected Monday as the high builds overhead. Seas of 3 to 4 ft
are possible during Sunday, otherwise they will subside to around
2 ft Monday with a weak pressure gradient overhead.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...None.
NC...Coastal Flood Advisory until 9 PM EDT this evening for NCZ107.
MARINE...Small Craft Advisory until 8 PM EDT this evening for AMZ250-
     252.

&&

$$
SYNOPSIS...SRP
NEAR TERM...JDW
SHORT TERM...CRM
LONG TERM...SRP
AVIATION...43
MARINE...



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.