Area Forecast Discussion
Issued by NWS Wakefield, VA

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971
FXUS61 KAKQ 180915
AFDAKQ

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

.SYNOPSIS...
High pressure slides offshore this morning, ahead of a cold
front approaching the region from the west. The cold front
moves across the area late tonight into Sunday morning,
producing scattered showers.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Latest surface analysis features ~1021mb surface high pressure
centered over the Virginia and Carolina coastal plain early this
morning. To the west, a large, positively-tilted upper trough
continues to drop across the Central Plains/Missouri River
Valley this morning, with the surface low centered over MO at
08z.

Quiet/benign weather lingers through the first part of the day,
as surface high pressure nudges offshore, with resultant low-
level return flow increasing around the offshore high.
Tightening pressure gradient due to the approaching front will
allow for breezy conditions through the afternoon with gusts of
25 to 35 mph (highest immediate coast and Eastern Shore). Took
down forecast highs slightly, but still expect temps to rebound
nicely w/compressional warming and  out ahead of the
approaching cold front. highs today into the mid/upper 60s SE
zones...upper 50a to mid 60s farther inland.

&&

.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 aftenroon. 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 /09Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions across area terminals will persist through the
06z 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...

&&

.TIDES/COASTAL FLOODING...
Gusty sw winds may push a few areas into the action stage during
Saturdays high tide cycle. Appears Bishops Head will approach
minor flooding thresholds then.

&&

.EQUIPMENT...
KDOX remains down until further notice due to 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 from 10 AM this morning to 10 AM EST
     Monday for ANZ630>632-634.
     Small Craft Advisory from 10 AM this morning to 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...MAM
NEAR TERM...AJZ/MAM
SHORT TERM...JDM/MAM
LONG TERM...AJB
AVIATION...AJB/MAM
MARINE...BMD
TIDES/COASTAL FLOODING...
EQUIPMENT...



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