Area Forecast Discussion
Issued by NWS Wakefield, VA

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FXUS61 KAKQ 240124

Area Forecast Discussion
National Weather Service Wakefield VA
924 PM EDT Sat Sep 23 2017

High pressure will continue to influence the weather pattern
through Sunday night. Hurricane Maria is forecast to move
northward between the offshore Atlantic waters and Bermuda
through most of the upcoming week. A cold front is expected to
cross the area by mid week and push Maria east of the region.


Latest MSAS has high pressure centered along the coast. Meanwhile,
cirrus well in advance of Maria is overspreading the southern
half of the fa. Main adjustment to grids overnight was to increase
the cloud coverage a bit across srn half of fa. Mstly clr skies
with patchy fog psbl away from the water. Lows from the upr 50s
wrn piedmont to mid 60s sern coastal areas.

The stacked high slowly slides eastward on Sun...preventing
Hurricane Maria from moving too far northward. Skies remain
mostly sunny with temperatures warming nicely to highs in the
mid-upper 80s inland (low-mid 80s beaches due to breezy NE
winds). Afternoon dewpoints falling into the upper 50s to
mid 60s will create ambient conditions that should feel
comfortable rather than humid.


Southern end of the stacked high begins to break down Sun night
as Hurricane Maria drifts northward but remaining well off the
Southeast Coast. Biggest change will be slightly warmer
overnight lows in the mid 60s (upper 60s to around 70F beaches)
as onshore/NE winds remain breezy in response to the pressure
gradient tightening between the sfc high to the north and Maria
to the south.

Maria continues to move northward on Monday with gradient winds
remaining persistently breezy from the NE. Gusts around
20-25 mph should be anticipated along coastal areas of
SE VA/NE NC...where farther inland, gusts should range from
15-20 mph. Clouds from the outer bands of Maria will start to
rotate into areas along the coast from NE NC to MD...especially
as the afternoon progresses. This should impact temperatures
near SE coastal areas with highs in the upper 70s to lower 80s.
Farther inland, less clouds present should allow temps to warm
into the mid- upper 80s. Isolated thunderstorms may be possible
Mon afternoon if the outer bands can make it far enough north to
rotate into far SE VA/NE NC coastal areas. Per 12Z data, models
in fair agreement in showing Maria`s center located an average
of 320 miles SE of Cape Hatteras by Monday evening with
variations in precip coverage, thus the reason why precip is
limited to isolated for Mon.

From Mon night into Tue, model consensus begins to fall apart.
The general trend among all models is for Maria to continue
pushing northward. However, the GFS is more progressive in
shifting its track NNW and closer to Cape Hatteras (around
160 miles ESE), whereas the ECMWF shows a slower northward track
and keeping the center around 225 miles SE of Cape Hatteras.
Despite model differences, the overall trend is for Maria to
approach the Mid Atlantic Region Mon night and Tue with precip
chances increasing during this time. Have broad-brushed POPs
into 6 hour segments in an effort to show the upward trend while
not putting too much detail into the forecast until models get a
better handle on how close Maria can get to the coast before
being pushed out to sea by a cold front and incoming upper
trough with stronger westerly steering winds aloft. Given model
differences, temperatures will be tricky...however dewpoints
will be on the rise into the upper 60s to lower 70s. Expect
increasing low temperatures Mon night (upper 60s to lower 70s),
and lower high temperatures on Tue due to more clouds/precip
across the area. Highs in the mid-upper 70s near the coast to
around 80F generally along/west of Interstate 95.


First part of the extended, Tuesday night through Thursday,
will be predicated on future track of Hurricane Maria. Latest
NHC track is a bit further west than 24 hours ago, which
increases the potential for some rainfall near the Bay/Ocean,
somewhat stronger winds, higher seas, and some coastal
flooding. Have utilized Superblend for tangible weather during
this period, given potential uncertainty in the track.

Models quite consistent after the daytime hours Thursday in
taking Maria fairly quickly northeastward away from the area. in
advance of upper trof dropping southeastward from Canada. This
trof and associated cold front move into the region next
Saturday /Day 7/.

Above normal temperatures continue through Thursday, with highs
from the upper 70s to mid 80s. Temperatures cool into the 70s
Friday/Saturday in the wake of Hurricane Maria. Lows Tuesday
night through Wednesday night range from the mid 60s to around
70F, then mid 50s NW to mid 60s SE Thursday night, and in the
50s Friday night.


VFR conditions prevail through the 00z TAF period, as high
pressure remains in control over the area. Some patchy MVFR/IFR
fog again possible tonight over ECG/PHF/SBY, although cirrus
clouds advecting over the southern parts of the region from
Maria may retard radiational cooling. However, little pattern
change and dew points are about the same as Friday.

Outlook: Generally VFR/dry conditions, with the exception of
patchy morning fog, are anticipated through Monday due to the
influence of high pressure over the region. Sub-VFR conditions
will be possible Tuesday through mid next week, primarily at
eastern TAF sites, as moist northerly flow from Tropical Cyclone
Maria overspreads the region.


Long period swell continues to propagate toward the coast with
seas generally 4-6 ft and the current Small Craft for Hazardous
Seas will continue in effect through Sun night (after that winds
will increase and the headlines will likely be converted to the
more usual Small Craft Advsy). Overall, expect seas of 4-6 ft
to persist Sunday/Sunday night, then build more significantly
Mon- Wed as ESE swell and some increasing winds arrive from slow
moving Maria. The bulk of the forecast guidance (as well as the
official NHC forecast) still keeps Maria offshore of the
Carolinas Tue into Thu, before it gets kicked quickly ENE out
to sea Thu night into Fri night. Based on the latest guidance,
have increased winds and seas fcst for Tue-Thu, with at least
SCA conditions expected all areas and the potential for Gales
over the lower Bay/coastal waters (or tropical headlines).
Either way, seas over the coastal waters should easily reach 10
ft or greater from Tue-Thu. Monitor the NHC forecast for the
official forecast track of Maria.


Tidal departures this aftn avg 1.0 to 1.5 ft across the entire
area. Minor flooding continues mainly across the upper Bay from
Lewisetta to Bishops Head through this evening. The following
high tide overnight/early Sunday will tend to be slightly lower
than the one this evening but will be close enough to just
extend the coastal flood advisory through Sun morning. Elsewhere
over the mid/lower Bay, the water levels peaked a few tenths
below minor flood thresholds earlier today, with the overnight
tide expected to be slightly lower so did not issue any
headlines for these areas. Water levels will tend to remain
elevated Sun-Mon, but overall most places should remain below
any minor flood thresholds. Will need to watch for additional
flooding next week, especially by Later Tue and Wed (and
perhaps Thu). This will depend on the exact track of Maria, but
the potential for significant tidal flooding exists (especially
over locations adjacent to the lower Bay and southern VA/NE NC
waters. High Surf advisories likely will be needed by late Mon
or Tue as well.

High risk for rip currents for all beaches adjacent to coastal
waters continues through Sunday, as 3-5 ft nearshore waves and
13-15 second swell persists.


MD...Coastal Flood Advisory until 9 AM EDT Sunday for MDZ021>023.
VA...Coastal Flood Advisory until 7 AM EDT Sunday for VAZ075-077.
MARINE...Small Craft Advisory for hazardous seas until 6 AM EDT Monday
     for ANZ650-652-654-656-658.


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