Area Forecast Discussion
Issued by NWS Wakefield, VA
FXUS61 KAKQ 021747
Area Forecast Discussion
National Weather Service Wakefield VA
1247 PM EST Fri Dec 2 2016
High pressure slowly builds into the Mid Atlantic through Sunday.
Low pressure passes south of the region Sunday night into Monday.
.NEAR TERM /THROUGH TONIGHT/...
Sfc high pressure continues to build across the region from the NW
today and tonight. Quiet wx prevails under a mostly clear sky. Forecast
highs today are in the mid 50s, which are near seasonal averages. Lows
drop into the low/mid 30s tonight.
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
Dry conditions will continue to prevail Saturday as wnw flow
dominates across the region and CAA improves. Mainly clear with
highs trending below normal in the upper 40s to low 50s.
High pressure becomes centered over the Mid-Atlantic region Saturday
night into Sunday. A split flow pattern develops aloft, with a srn
stream system tracking into the Lower Mississippi Valley, and a nrn
stream wave diving into the Great Lakes. This will result in dry
conditions Saturday night, with a mostly clear sky Saturday evening,
followed by increasing clouds later Saturday night, and then mostly
cloudy by Sunday. Forecast lows Saturday night range from the upper
20s to low 30s inland to the mid/upper 30s for se coastal locations,
with highs Sunday in the upper 40s to around 50.
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
High pressure over the Mid Atlantic States will loosen its grip
Sunday night. Mid level moisture will increase Sunday night and
early Monday over the area. Support for precipitation is rather
disorganized bur for now kept 30 percent POPs for light rain late
Sunday night. Any precipitation should move quickly off to the
southeast Monday morning.
An upper level trough will move out of the southern Great Plains and
form a surface low over the Lower Mississippi Valley Monday night.
This low will northeast through the Tennessee Valley and emerge east
of the mountains over Maryland or southern Pennsylvania.
Chances for rain begin to develop from the southwest Monday night
with a likelihood for rain across the area on Tuesday. The chance
for rain then diminishes Tuesday night and Wednesday. A strong
cold front crosses the region Thursday from the west and this
will bring another chance for rain.
High temperatures will start a bit below normal Monday and warm up
slowly the rest of the week. Highs Monday 50 to 55 will range from
the mid 50s to lower 60s by Thursday. Lows are forecast to range
through the 30s Tuesday morning and in the upper 30s to mid 40s
Thursday and Friday mornings. Following the cold front Thursday...
somewhat colder temperatures are likely.
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
VFR thru the 18Z TAF period. High pressure builds in from the west
tonight through Sunday leading to dry weather. West winds may
occasionally gust to 15-20 kt until sunset, decrease to 5-8 kt
tonight, then gust again at times Sat out of the NW. SKC through
the TAF period with increasing clouds Sat night/Sun. Next chance
of showers arrives Sun night, with the rain likely into Tue with
MVFR conditions at times.
Latest obs reflect NNW flow ~10-15 kt across the waters this
morning. Still noting a few marginal SCA gusts at elevated sites,
and did have a brief period of SCA force gusts earlier this morning
in association with a brief tightening of pressure gradient as sfc
low pressure drops across New England. Gradient will slacken a bit
this morning and early this afternoon, allowing winds to diminish
slightly this morning. Expect gradient will strengthen once again
late today and tonight, allowing for a stronger, more persistent
secondary (NW) surge tonight. H925 winds increase to 30-35kt
overnight, and given strong lapse rates, a few gusts to low end gale
are possible Saturday Morning over northern waters and even north of
Windmill Point in the Ches Bay. However, given slackening gradient
and winds aloft with departing New England low pressure and w/ V-
Wind anomalies lingering no lower than ~ -1 Std. Dev Sat morning, a
period of strong SCA conditions are favored over Gales, and thus
gone directly to SCA flags. SCA has been issued for the Chesapeake
Bay, Currituck Sound and the Atlantic Coastal waters for tonight
into the aftn on Saturday. Winds remain offshore through the period,
and have gone closer to wavewatch solution, building seas (4-6 ft)
by Saturday morning over the coastal waters (2-3 ft Bay), highest
seas out by 20 NM marker. Winds drop below SCA thresholds Saturday
afternoon and night, as high pressure builds in from the w-sw.
Winds diminish later Sunday and Monday, before a turn to an easterly
component Tuesday ahead of a complex low pressure system that will
lift northeast from the Lower Mississippi Valley. Seas may build to
around 5 feet once again in the outer portion of the coastal waters
around as early as Tuesday, potentially lasting through mid week.
MARINE...Small Craft Advisory from 6 PM this evening to noon EST
Saturday for ANZ632-634-654-656-658.
Small Craft Advisory from 6 PM this evening to 7 AM EST
Saturday for ANZ633.
Small Craft Advisory from 6 PM this evening to 6 PM EST
Saturday for ANZ630-631-650-652.