Area Forecast Discussion
Issued by NWS Wilmington, NC
FXUS62 KILM 250956
Area Forecast Discussion
National Weather Service Wilmington NC
556 AM EDT SAT JUN 25 2016
A cold front will slowly drop south and across the area today,
bringing a chance of showers and thunderstorms to the region.
High pressure will build in behind the front tonight with drier
weather arriving for Sunday. Shower and thunderstorm chances will
increase early next week as high pressure moves off the coast and
moisture returns to the region.
.NEAR TERM /THROUGH TONIGHT/...
As of 545 AM Saturday...The mid-level trof line pushes off the
east coast early this morning, resulting in flow aloft becoming
nw. The mid-level ridging will amplify this period, with the upper
ridge axis extending from the central Gulf coast states to the NE
States. Not your normal upper ridging orientation but this process
allows the sfc cold front to continue to drop se reaching the
coast later today...and off the coast and further south of the FA
tonight. a 1025 mb High centered over the NE States will ridge
southwest across the Carolinas later tonight. The cold front,
leftover outflows and embedded mid-level s/w trofs will provide
the necessary forcing to atleast initiate convection. Instability
already present will increase-some once the days insolation
commences. Some of this activity although isolated is already
ongoing. As we go thru the day, the primary activity will switch
from all areas to just along the coast by the end of daylight
hours. Can not rule out an isolated strong or even severe tstorm
today, however the FA will NOT see a repeat of Friday. Will
highlight the isolated severe in the Hazardous WX Outlook (HWO).
The drier and the slight cooler air will slowly infiltrate the FA
late today thru tonight. Will stay close to a model mos consensus
for max temps in the upper 80s to lower 90s. Even the coastal
sites will see max temps flirt with the 90 degree level. The heat
index values will push to around 100 degrees across the sw
portions of the ILM CWA and will highlight in the HWO. Tonights
mins in the upper 60s to lower 70s.
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 3 AM Saturday...The upper ridging from the Near Term Period
will persist Sunday into early Monday. The mid-level ridging is
progged to break down late Monday thru Monday Night in response to a
potent closed low within the main band of westerlies aloft.
It is progged to move eastward along or in the vicinity of the U.S.
and Canada border reaching the Great Lakes during Monday.
This closed low is progged by the models to open up and become
nearly a full latitude mid-level trof by Tuesday morning. The
Southeast U.s. becomes under the influence of this upper trof with
heights decreasing. For Sunday and for the most part daylight Monday
will be pcpn free. With sfc ridging and flow from this high across
the fa, temps both days and nights will actually hover around the
normal values for this time of the year. With Upper 80s to around 90
for maxes and upper 60s to around 70 for mins. For Monday night, the
approach of a sfc cold front and also the mid-level trof both from
the west will likely result with an increase of pops especially
during the pre-dawn Tue hours.
.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 3 AM Saturday...Mid level pattern will be undergoing a
transition to broad 5h troughing over the eastern CONUS as the
period begins. On Tue, northwest flow aloft, as the 5h ridge
retreats west, will move afternoon Piedmont trough convection to
the coast. Continued northwest flow Wed helps push a cold front
into the region, increasing precip chances midweek. Front ends up
stalled in the area Wed night and Thu as the 5h trough flattens
and the mid level push weakens. Abundant moisture along with
diurnal instability in the presence of the boundary will maintain
elevated precip chances for Thu. At this point hard to pick a
favored location, something which will depend on the location of
the stalled surface boundary. Shortwave trough dropping into the
TN Valley late Thu into Fri pulls the front back north, setting
the stage for widespread diurnal convection as the period ends.
Temperatures will be near climo through the period.
.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...Surface cold front will be dropping to the southeast
very slowly this morning, pushing across the inland terminals
around or up to several hours after daybreak. The flow aloft
is progged to sharpen or amplify later this morning thru tonight.
This will push the sfc cold front to the carolina coasts this
afternoon...and finally south of the ILM CWA by evening. Depending
on the amount of instability, forcing from the cold front and
the dynamics from the passage of weak embedded s/w trofs within
the nw aloft aloft, convection chances to remain in the chance
category. For now have indicated VCTS from noon thru early this
evening. As the front approaches expect winds from the sw-wsw, as
it pushes across the region expect w to nw, and finally it pushes
south of the area expect ne-e. The sfc pg will remain rather
relaxed thru the period with wind speeds 10 kt or less during
daylight and 5 kt or less at night.
EXTENDED OUTLOOK...Mainly VFR. Except for brief MVFR/IFR
conditions from convection today and again Tue into Wed. And
possible mvfr from fog each early morning.
NEAR TERM /THROUGH TONIGHT/...
As of 545 AM Saturday...The overall trend for this period will be
the diminishing wind speeds, and, the veering of the wind
directions from the sw-w this morning to the ne- ene after the cfp
later today thru tonight. This cold front will slowly drop sse and
should exit the southernmost ILM waters by early to mid evening.
Models lately have been too aggressive in quickly dropping these
fronts to, thru, and across the area waters. And as a result, I
backed off by 3 to 6 hrs and thus the mid evening time- line.
There really is no big pump of drier air or cooler air behind this
cfp. The models indicate a tightened gradient after the cfp during
Sunday but is only temporary. In all, should see wind speeds 10 to
15 kt with gusts up to 20 kt thru today, dropping back to around
10 kt tonight. Significant seas will run 2 to 4 ft and mainly be
governed by the wind driven variety at 4 to 6 second periods.
SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
As of 3 AM Saturday...The 1025 mb High centered over the NE states
on Sunday, will ridge sw across the Carolinas on Sunday.
a brief mini surge will occur on Sunday under ne to ene winds at 10
to around 15 kt. This due to a temporary tightening of the sfc pg
not a major influx of cooler air or drier air. The High will get
kicked off the coast and offshore from the NE states on Monday. Its
sfc ridge axis across the area Sunday will dissipate as the High
itself pushes east of the waters early Monday. A cold front will
make its approach from the west Monday Night. Winds will generally
veer from the east late Sunday night or early Monday to the s or sw
during Monday night. The sfc pg will become relaxed with resulting
wind speeds around 10 kt at best.
Significant seas will run 2 to 4 ft Sunday, then slowly subside to
around 2 ft by late Monday and Monday night. Wind driven waves at 4
to 5 second periods will dominate on Sunday. For sunday night thru
Monday night, an easterly ground swell at 8 second periods will
become the dominant player for significant seas.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
As of 3 AM Saturday...High pressure off the East Coast will
maintain southwest flow over the waters Tue into Wed. A cold front
will approach from the northwest but end up stalling just west of
the waters Wed. Seas will run 2 to 3 ft during the period.