Area Forecast Discussion
Issued by NWS Wakefield, VA

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000
FXUS61 KAKQ 201137
AFDAKQ

Area Forecast Discussion
National Weather Service Wakefield VA
637 AM EST Mon Nov 20 2017

.SYNOPSIS...
High pressure moves across the southeastern states through
tonight, then slides offshore through Tuesday morning. Low
pressure will move northeast along the Mid Atlantic coast
Tuesday night ahead of a cold front that pushes offshore
Wednesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Latest weather analysis reveals ~1026mb surface high pressure
over the Mid-South. The surface high will slide east across the
Carolinas this afternoon, before sliding offshore late tonight.
Lingering mid clouds have abated over northern Mid-Atlantic/Delmarva
this morning, and expect plenty of sunshine later this morning
and this afternoon. Highs today mainly in the upper 40s to near
50 on the eastern shore...to lower 50s inland. Mainly clear
tonight with lows in the upper 20s to mid 30s.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
The sfc high slides off the coast to begin the day on Tuesday.
Resultant strengthening return flow initiates a short-lived
warming trend, with highs 60-65. After a sunny start, some mid
to high clouds begin to filter in from sw to ne. A quick moving
northern stream system lifts from the TN Valley into the
northeast Tuesday night into Wednesday, pulling a cold front
east to the Atlantic Seaboard by Tuesday night. Weak sfc low
lift N-NE along the Carolina/Mid-Atlantic coast Tue night and
Wed. Moisture from the system lifts north with the best lift
remaining along the coast. Expect a period of showers mainly
along and east of I-95 after midnight Tuesday night/early
Wednesday morning. Likely pops along the bay and coast...chc
pops inland. Chc pops along the MD coast Wed morning then drying
out. Qpf generally under one quarter inch. Lows Tue night in
the 40s to near 50 se. Highs Wed in the 50s except near 60
across nern NC.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
High pressure builds into the area Thursday resulting in a dry but
cool holiday. Lows Wed night in the 30s to lwr 40s se. Highs Thurs
in the upr 40s to lwr 50s.

Another area of low pressure develops off the se coast late in the
week but it appears the high to the north keeps any significant
moisture south of the local area. Dry and continued cool Fri.
Highs 50-55. Next cold front approaches from the NW late Sat
then crosses then area early Sun. GFS wetter than ECMWF so will
go with low chc pops Sat night for now. Warmer Sat ahead of it
with highs 55-60. Lows Sat night in the 40s to near 50 se.
Cooler behind it Sun with highs mid 40s-lwr 50s.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
VFR conditions across area terminals this morning, with VFR
conditions to prevail through the 12z TAF period and into
Tuesday evening, as high pressure builds back into the region
later today through tonight.

Outlook: High pressure slides offshore early on Tuesday. A
weak trough of surface low pressure develops along the Carolina
coast Wednesday with scattered showers possible at area
terminals by later Tuesday into early Wednesday. A brief period
of sub-VFR conditions are possible over the terminals during
this timeframe.

&&

.MARINE...
Update...W-NW winds still 15-20kt along eastern side of Ches Bay
and all coastal waters. Gusts to around 25 kt north of Parramore
Island. Seas are persistently 3-5ft and have therefore extended
SCA flags for srn waters to end at 1000 AM (same time as nrn
waters) this morning.

Previous discussion...Otherwise, relatively quiet conditions
anticipated the rest of today through tonight as high pressure
becomes centered over the Carolinas and slides offshore late
tonight. W-NW winds becoming S-SW tonight with sub-SCA speeds. A
Canadian low pressure system will drag a cold front into the
Ohio Valley Tue...approaching the waters late Tue night.
Pressure gradient tightens over nrn half of area during this
time. SW winds should average 10-15kt north/5-10kt south Tue and
diminish through Tue night as wind direction becomes more
westerly late. Seas 2-4ft north/2-3ft south this aftn through
Tue night. Waves generally 1-2ft. Meanwhile, low pressure
develops off the Carolina coasts and tracks northeast...passing
well east of Cape Hatteras by Wed aftn. Next chance for SCA
conditions should be Wed/Wed night for all waters except York,
Rappahannock, and upper James rivers. Seas 3-5ft; waves 3-4ft.
High pressure rooting itself over the Ohio Valley to TN/mid-
Mississippi valleys Wed night through Thu night will allow
another low pressure wave to track northeast from the Southeast
Coast to an offshore location farther east of Cape Hatteras
during this time. Best pressure gradient appears to stay well
south of the local waters, therefore sub-SCA N-NW wind speeds
are anticipated. Seas slowly subside from 3-5ft Thu to 2-4ft Thu
night/Fri. Waves 2-3ft subsiding to 1-2ft during same
timeframe. High pressure builds into the Mid-Atlantic Region for
Fri with light and variable winds expected.

&&

.EQUIPMENT...
The fan on the temperature sensor at the Richmond ASOS (KRIC)
has likely failed, causing erroneous temperature readings. The
contract observer is augmenting the official METAR observations
(Hourly METAR and SPECIs). However, the 5-min high resolution
data is automated directly from the sensor and is subject to
reporting this erroneous data. As such, do not rely on the 5 min
temperature data from KRIC until our techs can repair the
sensor, likely on Monday.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory until 10 AM EST this morning for
     ANZ630>632-634-650-652-654-656-658.

&&

$$
SYNOPSIS...ALB/MAM
NEAR TERM...ALB/MAM
SHORT TERM...MPR/MAM
LONG TERM...MPR
AVIATION...AJB/MAM
MARINE...BMD
EQUIPMENT...



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