Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wakefield Virginia
330 PM EDT Wed Oct 26 2016
high pressure remains near the local area through tonight. A cold
front approaches from the northwest Thursday afternoon and crosses
the area Thursday night. High pressure returns Friday.
Near term /until 6 am Thursday morning/...
sfc hi pres remains near the coast through most of tonight. Lo
pres will be tracking east invof lower Great Lakes...spreading broken-
overcast clouds across the forecast area (mainly nrn portion) overnight. Winds
become more S through the night...and increase a bit...especially
at the coast...leading to a milder night. Lows from the u30s-l40s
on the Eastern Shore to the M-u40s elsewhere.
Short term /6 am Thursday morning through Saturday/...
lo pres continues east into New England by late Thu/Thu eve...W/ its
trailing cold front arriving Thu eve/night. Period of higher
moisture and at least weak forcing result carrying chc pops most
places by late Thu afternoon into the eve...then tapering off west to
east after midnight Thu night. Highest pops (40-55%) from nrn neck Virginia
to the Maryland eastern...W/ 15-30% elsewhere. Quantitative precipitation forecast through 12z/28 from T
to about .25". Highs Thu m60s north to l70s se.
The front pushes offshore late Thu night into early Fri morning
with sfc hi pres returning by aftn. Clouds are expected to
decrease rather quickly Friday...W/ most of the area becoming
sunny by late morning and aftn. Lows Thu night from around 50f northwest
to the u50s southeast. Highs Fri in the low 60s to around 70f.
Sfc hi pres slides S of the region Sat W/ zonal Flo aloft. Deep
layered west-southwest Flo leads to substantial warming by Sat afternoon.
Mainly skc Fri night-Sat. Lows Fri night ranging through the 40s.
Highs Sat from the u60s-around 70f on the ern shore to the l-m70s
Long term /Saturday night through Wednesday/...
another low pressure system skirts north of the area (primarily
along the St Lawrence River valley) and drags a weak sfc front
across the area Sat night. There are some model discrepancies
regarding shortwave energy passing through the region behind the
front on Sunday with a weak sfc low developing in the Lee of the
Appalachians late in the day. Tried to split the difference
regarding precip placement and limited to 15% pops since the end
result may be more clouds than precip Sunday aftn/evening.
Otherwise, high pressure will persist over the mid Atlantic
region Sunday into most of next week. Warm Sat/sun nights with
temps running 5-10 degrees above normal (lows in the 50s) and highs
on sun 5-7 degrees above normal (highs in the 70s). Expect a
slight cool down Mon-Tue with highs in the mid 60s to lower 70s.
Lows Mon/Tue nights in the upper 40s to mid 50s.
Aviation /19z Wednesday through Monday/...
a ridge of high pressure extending south of Canada and into the mid
Atlantic states is expected to continue to influence the weather
through much of the 18z taf period. The ridge will continue to shift
toward the coast this evening. A cold front will approach the area
tomorrow afternoon, bringing the potential for a few showers.
Seeing clear skies across all taf sites this afternoon with only a
bit of stratus across portions of central Virginia. Winds continue to
remain generally light and variable. VFR conditions are expected to
prevail through the 18z taf period. Winds will continue to increase
ahead of an approaching cold front, which will limit fog potential
Outlook: a low pressure system moving from the Midwest to the
northeast states will drag a cold front through the region Thursday
evening. High pressure returns Friday and Saturday and settles off
the coast as another cold front approaches from the west on
Small Craft Advisory flags raised Thu aftn through Fri aftn/evening.
High pressure slides offshore this evening and pushes ewd overnight
as a sfc low moves across the Ohio Valley. NE-east winds aob 10kt will
veer around to a more southeast direction Thu morning as the Ohio Valley
low pressure system tracks along the St Lawrence River valley. The
sfc pressure gradient tightens up as the day progresses and most
especially as a cold front gets dragged through the region Thu
evening and across the waters after midnight Thu night. Expect
winds to be southeast-S 10-15kt in the morning...becoming more S by Thu
aftn. Solid Small Craft Advisory conditions develop as early as Thu aftn as wind
speeds increase to 15-20kt with gusts of 25-30kt Bay/coastal waters
Thu aftn through Thu night...followed by Currituck Sound/mouth of
James River with speeds of 15-20kt Thu evening and overnight. The
mouth of the York river may experience gusts around 20kt for a few
hours late Thu evening, however this timeframe is not long enough
to justify Small Craft Advisory flags here at this time. Seas build to 3-5ft/waves
3-4ft on the Bay. The cold front exits the coast by Fri morning,
however Small Craft Advisory conditions will persist during the daytime hours until
winds start to diminish Fri aftn and seas drop below 5ft early Thu
evening. Expect breezy northwest winds 15-20kt Fri morning...diminishing
to northwest 10-15kt by Thu evening.
High pressure builds over the Ohio Valley on Fri and then slides
over the southeast states by Sat. Another low pressure system skirts north
of the area (once again along the St Lawrence River valley) and
drags a weak sfc front across the waters Sat night. A brief SW surge
may be possible, however speeds remain aob 15kt at this time. High
pressure will then persist over the mid Atlantic region sun into
most of next week.
Marine...Small Craft Advisory from 2 PM Thursday to 1 PM EDT Friday for
Small Craft Advisory from 8 PM Thursday to 6 am EDT Friday for
Small Craft Advisory from 4 PM Thursday to 6 PM EDT Friday for