Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
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FXUS61 KAKQ 241001
Area Forecast Discussion
National Weather Service Wakefield VA
601 AM EDT Mon Apr 24 2017
Low pressure will linger off the southeast coast through Tuesday,
then slowly lift northeast off the Mid Atlantic coast Wednesday.
High pressure builds into the area for the second half of the week.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Latest weather analysis reveals 1020+mb surface high pressure in
place from the northeast coast to just off of the coast of SE
New England. To the south, surface low pressure continues to
lift across SE GA toward far S SC...with the frontal boundary
extending E-NE along the SC coast and offshore. Aloft, objective
analysis shows the deepening mid/upper level low pushing across
the lower MS River Valley toward the Deep South.
Low level wedge is still well established over the FA early this
morning...w/ moisture transport N providing cool/cloudy wx w/
ongoing periods rain. Lingering Light rain and drizzle persists
early on this morning, before a more widespread, steadier
rainfall takes hold later this morning and this afternoon as
better overrunning moisture pushes into the area, as upper low
reaches the SE coast and begins to take on a Neg tilt.
Continued mainly likely to categorical POP continues w/periods
of rain. Highs mid to upper 50s in the piedmont to around 70
along the se coast. QPF 1/4" to 1/2", highest out in the
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
No major changes in forecast rationale this morning. The
primary forecast concern with this system comes tonight and
Tuesday when the tropical moisture off the Florida coast gets
entrained then rotates nnw around the vertically stacked system
as it slowly lifts north along the Mid-Atlantic coast. SPC WRF
shows area of heavier showers and t-storms lifting NE from the
coastal front, reaching our area overnight. Therefore, do
continue to expect the pcpn type to go back to more of a
convective one, at least along the coast. Lows tonight/early
Tuesday from near 50 NW to the lwr 60s SE. A bit more humid
Tuesday with highs in the low-mid 60s NW to low- mid 70s SE.
Pcpn tapers off west to east Tuesday night/early Wed with lows
in the 50s. Decreasing cloudiness and warmer Wed. Highs in the
upper 60s to lower 70s NE zones...middle to upper 70s inland.
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Long term period will feature above normal temps with mainly dry wx.
For Wed night/Thu, deep SWly flow develops across the eastern
seaboard as the aforementioned low pushes off to the NE. An upper-
level ridge then builds in through the weekend allowing for warm
temps and dry wx as most of the energy aloft will stay N and W of
the local area. At most a 20% chance of a late day shra/tstm Fri and
Sat. High temps Thu through Sun in the 80s, pushing upper 80s on
Sat. Low temps in the 60s.
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
As of 08z...Weak high pressure was south of New England and a
complex area of low pressure was over Georgia and Srn SC. The
area of low pressure will slowly spread into the Carolinas
Dry air that is a result of the high to the north was keeping SBY
mainly dry and VFR early this morning. In the mean time...areas
of light rain were moving through the rest of the TAF sites
with periodic MVFR conditions. Expect rain to become more
widespread later this morning/aftn with IFR ceilings increasing
in coverage from south to north after 12-14z. Winds will
continue from the northeast and will be gusty at times (15-23
kts) especially near the coast.
OUTLOOK...Low pressure will strengthen near the Carolina coast
tonight and Tuesday spreading heavier rain and more consistent
IFR conditions to the area. Winds will be mainly from the east
and will be gusty over eastern portions. As low pressure moves
up the coast rain and degraded aviation conditions will begin to
diminish by early Wednesday. Dry weather is in store Thursday
and Friday as high pressure builds over the Southeast States.
Latest surface analysis depicts high pressure off the Northeast
coast and low pressure over the Southeast. The result is ongoing
northeast flow over the local waters. Have seen an uptick in speeds
early this morning as pressure falls and increasing low level winds
spread over the waters. Gusts to around 30 knots observed in the
southern coastal waters and lower Chesapeake Bay. Seas average 4-6
feet and waves 2-4 feet. Low pressure slide off the Southeast coast
today as high pressure slides farther offshore. Sustained winds
average 20-25 knots with gusts to around 30 knots over the Bay and
coastal waters north of Cape Charles Light. Gradient winds diminish
over the southern waters and Sound later this morning, with SCA
headlines dropping off for the sound. Rivers average 15-20 knots.
Seas build to 5-8 feet in the northern coastal waters this
afternoon and subside to 4-6 feet in the southern coastal waters.
Waves average 3-5 feet. Low pressure lifts over the eastern
Carolinas tonight. Anomalous easterly low level flow spreads over
the waters late tonight ahead of the advancing surface low. Pressure
falls of 3-6mb in 6 hours will help mix some of the higher velocity
winds aloft (925mb winds of 45-55 knots) to the water. As a result,
have issued gale headlines for the lower Bay and coastal waters late
tonight into Tuesday morning for gusts of 35 to 40 knots. Have also
added the lower James to gale headlines for a 3-6 hour period of
gale gusts to around 35 knots. As the strong easterly winds
overspread the waters, seas will build quickly to 7-10 feet. High
surf advisories have been issued for all coastal areas. Low pressure
lifts over the waters Tuesday afternoon, with improving conditions
over the southern coastal waters and lower Bay. Seas slowly subside
to 5-9 feet (highest north). Low pressure centers over the waters
Tuesday night as winds diminish at or below 15 knots. However, seas
will be slow to subside as the low lifts north of the waters through
Wednesday. Still anticipate 4-7 foot seas Wednesday afternoon. Waves
Sub-sca conditions expected all waters Thursday as the low
weakens north of the waters. The next front approaches the waters
Friday, stalling over the northern waters Friday night.
-- Changed Discussion --Current tidal departures are averaging around 1 to 1.5 feet in
the lower Bay and southern coastal waters due to ongoing onshore
flow. Have issued another round of coastal flood statements for
this mornings high tide across the lower Bay and lower James
river. Levels are expected to fall below minor flooding
thresholds. Tidal anomalies increase to 1.5 to 2 feet through
tonight as northeast flow increases. Water levels are expected
to stay below minor flooding thresholds again this evening into
early tonight. Increasing easterly flow ahead of low pressure
lifting over the Carolinas tonight will result push tidal
departures toward 2 feet late tonight/early Tuesday morning. The
elevated departures will coincide with high tide across the
lower Bay and coastal areas. Minor/nuisance flooding is
expected. Depending on the exact track of the low, high end
minor to low end moderate coastal flooding is possible Tuesday
night. Departures subside Wednesday as low pressure lifts along
the Northeast coast and flow becomes offshore.
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-- Changed Discussion --MD...High Surf Advisory from 6 AM to 4 PM EDT Tuesday for MDZ025.
NC...High Surf Advisory from 4 AM to 10 AM EDT Tuesday for NCZ102.
VA...High Surf Advisory from 6 AM to 4 PM EDT Tuesday for VAZ099-
High Surf Advisory from 4 AM to 10 AM EDT Tuesday for VAZ098.
MARINE...Small Craft Advisory until 1 PM EDT Tuesday for ANZ635>637.
Small Craft Advisory until 4 AM EDT Tuesday for ANZ632-634-638-
Gale Warning from 4 AM to 10 AM EDT Tuesday for ANZ632-634-638-
Small Craft Advisory until 7 AM EDT this morning for ANZ633.
Small Craft Advisory until 6 PM EDT Tuesday for ANZ630-631.
Gale Warning from 4 AM to 1 PM EDT Tuesday for ANZ650-652-654.
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