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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KAKQ 121617
AFDAKQ

Area Forecast Discussion
National Weather Service Wakefield VA
1217 PM EDT Sat Aug 12 2017

.SYNOPSIS...
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A cold front will slowly approach from the northwest this
afternoon, and slowly sag south through the local area this
evening. Numerous showers and scattered thunderstorms can be
expected through this evening. The front will stall across North
Carolina on Sunday, and will push back north Sunday night into
Monday as a wave of low pressure moves along the boundary.
Additional areas of low pressure will move along the front into
Tuesday, with high pressure finally building north of the region
by Wednesday.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Ongoing convection has been persistent and excessive invof the
eastern shore (esp over MD), and has now finally waned/pushed
offshore. An area of 4-8" of rain in the vicinity of SBY
prompted Flash flood Warning earlier that has now been replaced
with a long duration flood warning into this evening (see
FLWAKQ for details). Scattered showers/tstms persist over the
remainder of the CWA. Partial clearing has developed over some
of southern/SE VA, though with the airmass unstable as heights
aloft fall this aftn, expect clouds and showers/tstms to rapidly
fill back in after 18Z. Will continue the flash flood watch
for far SE VA-NE NC due to recent rainfall past few days and as
this will tend to be the axis of the heaviest additional rain
for the late aftn into the evening timeframe. Adjusted current
temperatures/dew pts to latest observations, but overall made
minimal changes, with highs mainly in the 80 to 85 degree range.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
The cold front crosses the FA tonight. Deepest moisture gets
shunted offshore and S...but enough lingering moisture to keep
likely pops going across the E...tapering off to chc PoPs
elsewhere. Lows ranging from the u60s NW to the m70s SE VA-NE
NC.

That frontal boundary will linger just S of the local area or
near the SE VA/NE NC border Sun afternoon thru Mon...maintaining
chc to likely PoPs across srn VA-NE NC into Sun night w/ PoPs
aob 15% central/N. PoPs remain 30-60% from srn VA to NE NC Mon
into Mon evening as the boundary remains nearly stationary.
Highs Sun and Mon 80-85F. Lows Sun night in the m-u60s N to
70-75F S.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
The period begins with more wet weather expected from Monday night
into early Wednesday as a frontal boundary remains stalled across
the Mid-Atlantic States and the Carolinas.  The biggest question has
been the location of the front which the GFS and ECMWF have had a
hard time reaching a consensus as run to run consistency has waffled
the front from over us to areas south of the forecast area.  The 12z
ECMWF run of the models has the front and associated surface wave
lifting over the Mid-Atlantic states while in the 12 GFS the front
remains south of the area and holds the bulk of the rain further
south over the Carolinas.  This is a flip from yesterdays runs.  So
for now, have generally played a scenario where the front stall near
the area and the wave of low pressure moves along the front and
should impact much of the area on Tuesday.  Have added likely pops
to SE VA and NE NC as this area appears to have the best chance of
rain on Tuesday/Tues night.

By Wednesday...the front will get drug south of the area as the wave
moves off the coast.  This will allow high pressure to build into
the area as the flow aloft turns nw as the upper trough swings
through the area.  This high will provide a couple dry days before
the next boundary crosses the area on Friday as the upper ridge over
the lower MS Valley and Southern Plains builds eastward.  There
could be some scattered convection along this warm front moves
through the area.

For temperatures...did go a little cooler on Tuesday with the idea
of clouds and rain, but without having a better handle on the
frontal position could easily see either much cooler temps, in the
70s, than shown or perhaps if the front lifts further north, it
could be more int he mid to upper 80s.  Once the front clears should
see drier conditions and initially having temps in the low to mid
80s with a warming trend into the second half of the work week with
readings back toward near normal values in the mid to upper 80s.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
VRB conditions through the TAF fcst period w/ periodic SHRAs
and ISOLD-SCT tstms (esp through 00-06Z/13) resulting in
IFR/MVFR CIGs and occasional VSBY restrictions. A cold front
settles just S of the local area tonight/early Sun. Generally
VFR conditions RIC-SBY Sun while periodic SHRAs/tstms and VRB
CIGs/VSBYs likely at other sites. Unsettled conditions with
periodic convection expected into/through early in the week as
the boundary stalls across the region with a series of
disturbances pushing across the area.

&&

.MARINE...
No headlines necessary with this forecast package. High pressure
remains well offshore today as a cold front slowly approaches
from the west. Expect southerly flow up to 10-15 kt with 1-2 ft
waves over the Bay and 2-3 ft seas over cstl wtrs. The front
drops into the area tonight then slides south near the Carolina
coast Sunday, remaining near there through early to mid next
week. A prolonged period of weak onshore flow is expected
during this timeframe with seas up to 3-4 ft.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
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MD...None.
NC...Flash Flood Watch until 8 PM EDT this evening for NCZ012>017-
     030>032-102.
VA...Flash Flood Watch until 8 PM EDT this evening for VAZ092-093-
     095>098-523>525.
MARINE...None.
-- End Changed Discussion --

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...ALB/TMG
LONG TERM...ESS
AVIATION...ALB
MARINE...MAS