Area Forecast Discussion
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FXUS62 KILM 051032
Area Forecast Discussion
National Weather Service Wilmington NC
532 AM EST Mon Dec 5 2016
Light rain will slowly wane through this afternoon as weak low
pressure moves away. A stronger system will move back into the
region tonight through Tuesday bringing more substantial
rainfall. Quiet and seasonable weather will occur mid-week
ahead of an arctic front which will cross offshore late
Thursday. Very cold temperatures will follow for Friday
and into the weekend.
.NEAR TERM /THROUGH TONIGHT/...
As of 330 AM Monday...The coastal warm front is now straddling
the immediate coast of the carolinas. Models indicated this
front would do this but with some difficulty on just how far
inland it will progress. The low pressure is now across Cape
Fear at the moment with the coastal front ahead of it having
pushed close to 10 miles onshore, via low 60s readings at ILM.
After the low`s passage, the coastal front will get dragged
back off the coast and offshore. This evident with latest NW
winds behind the low across the ILM SC CWA at the moment. The
low will track NE of the ILM NC CWA later this morning, pulling
the remaining inland portions of the coastal front back
offshore. Overrunning light to moderate rains will come to an
end from SW to NE later this morning thru early afternoon.
Radar indicates an axis of higher intensity rain this morning
extending from Timmonsville northeast across Latta and
Evergreen to White Lake. This will end up being the area of
hier rainfall totals for this round of pcpn.
For late this afternoon thru tonight, wedge of high pressure
with CAA at the sfc, will set up across the area. The cutoff
upper low over Mexico late this weekend, will get picked up by
the upper westerlies and track to the NE, opening up into a
potent s/w mid-level trof by late tonight as it and it`s
accompanying sfc low reaches the lower Mississippi Valley. The
offshore front from earlier will return northward as a warm
front...reaching the coast by tue daybreak. Expect overrunning
light to moderate rain to once again overspread the FA later
this evening and overnight.
Todays highs along the immediate coast will likely occur early
this morning with 60s. Otherwise, highs inland will occur
during the normal diurnal cycle. ie. afternoon. Tonights lows
will be a blend of mos guidance.
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 415 AM Monday...The potent mid-level s/w trof, over the
lower to mid Mississippi Valley and associated sfc low, will
lift to the NE reaching the Ohio River Valley by Tue afternoon.
The associated sfc low will fill in, with a new low pressure
system taking shape off the Southeast NC Coast. Ie. The Miller
Type B Scenario. An occluded front will exist between the 2 sfc
lows, that will dissipate as the coastal low becomes the
dominate low. Meanwhile, wedge of high pressure across the area
will remain strong due to the parent center of the sfc high
remaining over the NE states well into Tue afternoon. This will
result in a continued influx of cool air at the sfc with ILM
inland areas remaining on the cool side. Once again, the front
offshore will get pulled north as a warm front, and likely
straddle along the immediate coast. Will have a nice range of
temps depending how far inland the warmer temps push. At this
point, it could be a repeat of what occurred on Monday or to a
lesser degree since the source of cool air to sustain the wedge
will be stronger. The better dynamics aloft with this system as
a whole, will aid in the possibility of isolated thunder in the
vicinity of the coastal front. Instability either at the sfc or
elevated will be enough for possible mention of isolated
thunder. Overall, looking at categorical overrunning rains
early Tue morning thru early afternoon, ending from SW to NE.
QPF will be equal or slightly hier than what occurs during
Monday. The heaviest pcpn ends during Tuesday afternoon. A
lagging mid- level weak s/w trof could ignite -shra Tues
evening and for that left a chance POP.
For Wed and Wed night, flow aloft no longer taps the Gulf as
WSW flow becomes the mainstay. Weak high pressure builds across
the FA. RH Model time heights displays indicate decent drying
aloft which will enable skies to become mostly clear for Wed
thru Wed night. Temps for Wed will run at or slightly below
normal with neutral advection.
.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 300 AM Monday...Arctic front to cross the Carolinas
Thursday, with very cold conditions following in its wake.
Guidance has slightly increased its moisture associated with
the FROPA, and will carry SCHC POP for northern zones late
Thursday as a few showers are possible. Increased column
saturation above 600mb suggests increased cloud cover, but very
dry air beneath this will prevent much more than a brief shower
or sprinkle with the FROPA. All precip will be of the liquid
variety however, it will be too warm for any snowflakes this
time around. However, it will certainly FEEL like winter
beginning Thursday night and persisting through Saturday as
temps plummet. 850mb temps have warmed slightly in new guidance
as the core of the cold air deflects to our north, but still
expect highs only in the 40s Fri/Sat with lows dropping well
into the 20s Friday night. Additionally, gusty winds Friday
will make apparent temps even colder than that. The Canadian
high pressure bringing this cold air will shift offshore
quickly late in the wknd allowing temps to recover to
seasonable values Sunday.
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
As of 06Z...Rain showers continuing to move SW to NE across
the area, and this persistent light rain will lead to
widespread IFR tonight. The rain will remain mostly light, so
vsbys are expected to be primarily MVFR, but brief IFR in
heavier rain is possible. More likely, the IFR will be
experienced in lowering CIGS, possibly falling to LIFR towards
dawn and early on Monday. Winds will be highly variable due
to a coastal front, with southerly winds developing at
ILM/CRE/MYR and N/NE winds continuing inland.
Drying will occur during the day Monday with slow improvement
to VFR during the aftn as 10kt NW winds clear the cigs and
rainfall. This improvement will be short lived however, as a
more significant round of rainfall is expected to begin Monday
night, with MVFR and IFR returning to the terminals.
Extended Outlook...IFR/rain likely Mon night through Tuesday
night. MVFR becoming VFR Wednesday and extending into Thursday.
Slight chance MVFR/showers Thurs night into early Fri.
NEAR TERM /THROUGH TONIGHT/...
As of 330 AM Monday...SCA thru this morning for all waters.
The coastal front this morning will straddle along the
immediate coast or up to 5 to 10 miles inland. Low pressure
moving along this front, across the Cape Fear area attm, will
track NE of the ILM CWA later this morning. After the low
passage, the coastal front will get pulled back across the
coastal and into the offshore waters later this morning and
afternoon. The south side of the coastal front is where you
will find the stronger SCA, SE to SW winds. Wind speeds will
reach 15 to 25 kt. Late today and tonight, when the front has
pushed back offshore, winds will become NE to ENE around
10 kt. High pressure wedging from the north tonight will add 5
kt, making it around 15 kt with some hier gusts overnight.
Significant seas this morning will have built to 4 to 7 ft in
the Cape Fear vicinity, and 4 to 6 ft elsewhere. Wind driven
waves at 3 to 6 seconds will dominate the seas thruout this
period. After the lows passage and offshore winds after the
coastal front bounces back offshore, seas will subside rather
quickly this afternoon into tonight before holding steady in
the 2 to 4 ft range.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 415 AM Monday...SCA conditions may again be met across
all waters during Tue into Tue night.
Front offshore Monday Night, will get pulled back to the north,
across the Coastal waters and possibly onshore during the 1st
part of Tuesday. Low pressure is expected to develop off the
southeast NC Coast Tue afternoon and track northeast away from
the local waters by Tue evening. This will pull the front, now
a cold front, back off the coast and offshore Tue evening. Weak
high pressure ridge in late Tue night and prevail thru Wed
night. Peak winds will occur during Tuesday, slowly abating Tue
night and continuing this trend thruout Wednesday. Significant
seas will also peak during Tue and mainly dominated by short
period wind driven waves. Seas will likely quickly subside Tue
night thru Wed due to the lack of any long period ground swell
progged to affect the local waters. PCPN will be widespread on
Tue with mainly light to moderate rains with embedded
thunderstorms. A few of these embedded thunderstorms could mix
down the progged stronger winds aloft that could yield a SMW or
atleast Marine wx statements. Activity becomes isolated Tue
night with drier air and no pcpn for Wed.
LONG TERM /THURSDAY THROUGH FRIDAY/...
As of 300 AM Monday...Strong cold front will cross the waters
late Thursday producing SCA conditions into Friday. Winds ahead
of this front will increase and slowly veer to the west, before
shifting to the NW and becoming 20-25 kts, driving seas up to
4-6 ft despite the offshore winds. These winds will remain
strong through Friday, falling only slowly to 15-20 kts while
becoming more northerly Friday night. Wave heights will fall
quickly however as the offshore winds weaken, becoming 2-4 ft
late. An SCA will likely be needed for late Thursday and a good
portion of Friday.
MARINE...Small Craft Advisory until 10 AM EST this morning for AMZ250-