Area Forecast Discussion
Issued by NWS Wakefield, VA

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FXUS61 KAKQ 181443
AFDAKQ

Area Forecast Discussion
National Weather Service Wakefield VA
943 AM EST Sat Nov 18 2017

.SYNOPSIS...
A strong cold front moves across the area Sunday morning. High
pressure builds into the area later Sunday through Monday, then
moves off the coast Tuesday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Current forecast on track with only minor adjustments made to
the grids late this morning. All pcpn associated with the warm
front is north of the fa and is progged to stay north of the
area this afternoon. Meanwhile, high/ mid level cloud deck will
continue to overspread the area throughout the day. Expect a
mstly cloudy and milder day ahead except pt sunny over the south
then mstly cloudy. Tightening pres gradient will increase the
SSW winds into the breezy if not windy category at times as the
day wears on. Dry with highs in the upr 50s-mid 60s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
Surface low will lift across the eastern Great Lakes toward
southern Quebec tonight into Sunday morning. Trailing cold front
will push across the area after midnight tonight, reaching the
coast around/just after dawn Sunday morning. Ahead of the front,
expect quick dewpoint surge as the warm front lifts across the
area Sat aftn/night. Low level S-SW flow quickly increasing PW
values into the 1"-1.25" range after 00z/Sun.

Still anticipate a quick-moving band of showers along and ahead
of the cold front just after midnight out in the piedmont,
reaching the coast by Sunday morning. Aforementioned increasing
PW, along with a narrow axis of low-level convergence/forcing,
will lead to a broken line of scattered to numerous showers
through the overnight period. Accordingly, have pushed pop into
high end likely/categorical range, highest over western
sections. CAPE is nearly nil through this period, some have
again held thunder wording out.

Breezy conditions persist through the night. H92-850 winds
increase to 40-50 kt as gradient tightens just ahead of the
front. Expect strongest winds to be within a few hours of
frontal passage as subsidence behind the departing boundary
mixes down some of that wind. A wind advisory was considered but
has not been issued with this package, with winds likely to be
just below criteria. That said, expect a small window of windy
conditions Sunday morning (especially north), with blustery and
chilly conditions continuing through Sunday. Temperatures
remain mild tonight before dropping off late tonight.
Temperatures struggle to rise Sunday morning, aided in small
measure by clear sky and sunshine, but remain steady/drop off
Sunday afternoon. Winds diminish late afternoon as the gradient
slackens. Cooler with highs in the 50s...to near 60 SE coast.

One last surge of wind possible with another passing
disturbance Sunday night. Blustery conditions ease through the
night as cool sfc high pressure centered over the TN Valley
expands east into the Mid-Atlantic late Sunday and Monday. We
can expect a clear sky and below normal temperatures. Lows
Sunday night in the mid/upr 20s Piedmont to the mid/upr 30s
coast. Highs Monday in the upr 40s to low 50s.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
High pressure moves offshore of the region during the day on Tuesday
allowing for a warming trend. Highs on Tuesday will climb into the
upper 50s to lower 60s and lows fall into the upper 30s to low 40s
inland (mid to upper 40s at the coast). Temperatures remain near
normal during the day on Wednesday before a mainly dry cold front
crosses the area Wednesday late afternoon/evening. Introduced a
slight chance of PoPs with the passage of the front, but moisture
appears fairly limited at this time. A cooler airmass moves into the
region for Thanksgiving and the end of the work week behind the
front. Temperatures are expected to be below normal for Thanksgiving
Day with highs in the upper 40s to low 50s and lows dropping into
the lower 30s away from the coast. An offshore trough develops on
Friday which will bring a chance of rain for coastal areas.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions across area terminals will persist through the
12z TAF period. Surface high pressure over the Mid-Atlantic
coast will slide offshore through this afternoon. Clouds will
gradually thicken/lower this afternoon and tonight as a strong
cold front approaches the region through tonight. Winds will be
gusty ahead of the front Saturday afternoon, gusting out of the
southwest between 20-25kt.

Outlook: The cold front crosses the area late tonight into
Sunday morning, with the possibility of some short-lived MVFR
ceilings with sct/numerous rain showers with the frontal
passage. LLWS will be a concern tonight into Sunday morning
just ahead of the front, 35-45kt at 2kft AGL. Winds quickly
swing around to the W-NW post-frontal and will be highest
within a few hours of frontal passage, but will remain gusty
through Sunday. High pressure builds back over the local area
Sunday morning, allowing for a return to VFR conditions through
the remainder of the weekend. High pressure gradually slides
off the Southeast coast Monday and Tuesday with VFR conditions
prevailing.

&&

.MARINE...
High pressure slides off the Carolina coasts today as a strong
cold front approaches the area from the west today. Winds a tad
slower to increase through this morning. By this aftn, SW winds
will increase to 15-20kt as the pressure gradient tightens
significantly with the high offshore and the cold front passing
through the Ohio Valley. 00Z model guidance shows impressive
pressure falls of 6-9mb occurring this aftn into this evening
ahead of the front. Expect SW winds to increase to 20-30kt with
gusts ranging from 25-35kt. The pressure gradient tightens up
more after midnight tonight with gusts increasing to 40kt all
coastal waters...mainly due to a strong temperature gradient
associated with this low pressure system. In addition, gusts
could reach up to 35kt over Currituck Sound between 200 AM to
900 AM. Will need to monitor gale gust potential here and
possibly the mouth of Ches Bay. Seas build to 3-5ft north/3-4ft
south this aftn...then build to 5-8ft north/5-6ft south after
midnight tonight. Waves build to 3-4ft this aftn...then build to
4-5ft late this evening.

Cold front crosses the waters around sunrise Sunday morning.
Strong cold air advection, a very persistent tight pressure
gradient, and rapid pressure rises (5-9mb) behind the front will
all contribute to a continuation of strong NW winds 20-30kt with
gusts of 25-40kt through Sunday. Windy conditions will be common
everywhere on Sunday (including over land areas) and generally
uniform with slightly stronger winds occurring over the warmer
waters. Winds should remain generally unchanged Sunday night
with NW winds averaging 15-25kt with gusts averaging 30kt. A
secondary surge in NW winds may be possible Sunday night as
coldest part of airmass swings across the area. However,
relaxing pressure gradient with high pressure building over the
Southeast States may prevent a surge from happening. High
pressure continues to build over the Southeast States into the
srn Mid Atlantic Region Mon/Mon night... sliding offshore on
Tuesday. Adverse boating conditions to subside during Monday
with more benign/quiet sub- SCA conditions anticipated through
Wednesday.

Gale warnings now in effect for all coastal waters from this
evening through early Monday morning. SCA flags begin on Ches
Bay by mid morning today through mid morning Monday morning.
River/Sound begin this aftn and persist through roughly sunrise
Monday morning. For specific details, please visit
www.weather.gov/wakefield/marinebrief.

&&

.TIDES/COASTAL FLOODING...
Gusty SW winds may push a few areas into the action stage
during todays high tide cycle. Nuisance type flooding may be
possible...especially in vicinity of Bishops Head this afternoon
and overnight.

&&

.EQUIPMENT...
KDOX remains down until further notice due to a pedestal fault.
Updates will be provided here and in FTMDOX as they become
available.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory from 1 PM this afternoon to 7 AM EST
     Monday for ANZ633-635>638.
     Small Craft Advisory until 10 AM EST Monday for ANZ630>632-634.
     Small Craft Advisory until 7 PM EST this evening for ANZ650-
     652-654.
     Gale Warning from 7 PM this evening to 4 AM EST Monday for
     ANZ650-652-654.
     Small Craft Advisory from 1 PM this afternoon to 7 PM EST this
     evening for ANZ656-658.
     Gale Warning from 7 PM this evening to 3 PM EST Sunday for
     ANZ656-658.

&&

$$
SYNOPSIS...MPR
NEAR TERM...MPR
SHORT TERM...JDM/MAM
LONG TERM...AJB
AVIATION...AJB/MAM
MARINE...BMD
TIDES/COASTAL FLOODING...AKQ
EQUIPMENT...AKQ



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