208
FXUS61 KAKQ 171901
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
301 PM EDT Tue Sep 17 2024

.SYNOPSIS...
Low pressure will slowly lift west to northwest along the
border of South Carolina and North Carolina this afternoon. The
system will continue to gradually weaken through Wednesday. Rain
showers expected through tonight, with the pattern remaining
unsettled Wednesday and Thursday.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
As of 300 PM EDT Tuesday...

Key Messages:

- Rain chances continue into this evening from south to north, rain
may be locally heavy at times and lead to instances of flash
flooding.

- A Flood Watch remains in effect for much of the area along and
east of I-95 (excluding the Maryland and Virginia Eastern Shore)
this afternoon.

Latest surface analysis shows a 1024mb high pressure juts off the
coast of New England. low pressure that was previously associated
with PTC8 continues to drift WNW along the North and South Carolina
and Georgia boarder before moving back to the NE later this evening.
Recent satellite and radar imagery shows multiple bands of showers and
thunderstorms across North Carolina and off the coast of Virginia.
The first band of showers and thunderstorms that brought rain into
far eastern North Carolina and the Tidewater area has slowly moved
off shore. These showers brought 1-2" localized 2.5" inches of rain
across Tidewater and 1-3" localized 4" inches across northeastern
North Carolina as of 2PM. This band is now bringing light to
moderate rain showers across the southern tip of the Lower Eastern
Shore. The second batch of showers and thunderstorms are now
initiating along a boundary that is localed across North Carolina.
This second boundary is expected to slowly propagate northward and
move an additional round of showers and possible thunderstorms into
northeastern North Carolina and southeastern Virginia later this
afternoon and into this evening. The environment that these showers
will be moving into will be optimal for additional heavy rainfall.
In far south eastern Virginia  instability has slowly been building
in with MLCAPE values ranging between 500-1000 J/kg. PWAT values
have continued to stay between 2-2.5 inches. Aloft, weak to moderate
950mb and 850mb winds continue to fetch moisture on shore and across
the area into this evening. Will note, CAMs have not been able to
handle the the convection well. Real time observations will continue
to be monitored. At this time the flood watch will stay in effect
until later this evening. Real time weather conditions will continue
to be monitored to see if the flood watch can be taken down or
extended.

Later on this evening the showers and thunderstorms will continue to
taper off. Winds across northeastern North carolina and southeastern
Virginia will become calm this evening. With calm winds and an
abundance of residual moisture patch fog is expected across that
region tonight and into the mid morning hours of tomorrow.
Visibility could drop  to 1-2SM with isolated heavier patches of fog
that could potentially drop visibility to less than 1SM. Visibility
should improve by the late to mid morning hours tomorrow.
Temperatures for tonight will remain mild as clouds prevent
temperatures to cool down. Lows are forecasted to be in the middle
to upper 60s inland and lower 70s along the coast.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
As of 300 PM EDT Tuesday...

Key Messages:

- Continued unsettled conditions Wednesday into Thursday with an
upper low lingering near the region.

- A backdoor cold front drops southeast across the local area on
Friday.

No big changes within the short term forecast. Shower chances
will continue both Wednesday and Thursday. However, Pops will
decrease during these days. An upper low gradually stalls south
of the area on Wednesday and gradually drift off to the
northeast on Thursday. With this system lingering Pops will
remain in the forecast. Wednesday the showers will be more
isolated to scattered in nature than widespread (best potential
across the western half of the area). With on shore continuing
for the week expect widespread cloud cover to continue to keep
temperatures cool (especially across the northwest) with highs
expected to range from the lower 70s NW to the lower 80s SE.
Cool and cloudy conditions continue on Thursday with decreasing
cloud cover late. Highs on Thursday will generally be in the mid
to upper 70s. A weak backdoor cold front will push SE across
the region during the day Friday, which will bring a slight
chance for an afternoon shower. Highs on Friday will range from
the upper 70s to around 80.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 300 PM EDT Tuesday...

Key Messages:

- Drier, cooler weather arrives this weekend into early next week.

Aloft, a tall upper level ridge builds well into Canada and
Greenland with an upper level trough along the East Coast this
weekend into early next week. At the surface, low pressure lingers
off the Mid Atlantic coastline through the weekend, gradually
shifting south Sun into early next week. Meanwhile, high pressure
remains centered in Quebec through Sat before dropping south into
New England by Mon. As the high pressure builds south, it will push
a backdoor cold front across the area Sat with cooler, drier weather
expected this weekend (especially Sun) into early next week.
However, given the low off the coast, coastal areas can expect
breezy conditions with gusts to 25-30 mph this weekend into Mon
along with greater cloud cover and humidity. Additionally, cannot
rule out a few isolated showers along the coast (15-25% PoPs).

Highs range from the mid-upper 70s to around 80F (across the
piedmont) Sat, mid 70s Sun and Mon, and mid-upper 70s Tue. Lows
range from the upper 50s (Piedmont) to mid 60s (coast) Fri night,
mid-upper 50s (Piedmont) to low-mid 60s (coast) Sat night, mid 50s
(Piedmont) to lower 60s (coast) Sun and Mon nights, and upper 50s
(Piedmont) to mid 60s (coast) Tue night.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
As of 155 PM EDT Tuesday...

Low pressure lingers over the southern Appalachians this
afternoon with widespread light to moderate rain across the
area and MVFR/IFR CIGs. Expect the heaviest rain to remain
generally near the coast (east of I-95) through this afternoon
with VIS occasionally dropping to IFR (1-2 SM). Rain continues
through tonight but should decrease in intensity. Additionally,
models are now hinting at the potential for fog across southern
VA and northeast NC late tonight into Wed morning with IFR VIS
possible (due to a combination of fog and drizzle). CIGs will
likely continue to bounce around from IFR to MVFR through this
afternoon before crashing to IFR/LIFR this evening across all
area terminals. CIGs continue to lower through the night with
200-500 ft CIGs possible across the terminals late tonight into
Wed morning. VIS improves by mid morning Wed, however, IFR CIGs
likely persist through the afternoon at RIC/PHF/ORF (lower
confidence at SBY). ECG likely improves to MVFR CIGs by Wed
afternoon. IFR CIGs will again be possible Wed night (MVFR at
SBY). E/ENE winds remain 10-15 kt with gusts 20-25 kt (highest
along the coast) this afternoon. Winds diminish to 5-10 kt
overnight (potentially below 5 kt across southern VA and
northeast NC). Winds become NE 5-10 kt Wed.

Outlook: Unsettled weather continues Wednesday through Friday,
but the degree to which this leads to flight restrictions is
uncertain.

&&

.MARINE...
As of 410 AM EDT Tuesday...

Key Messages:

- Small Craft Advisories remain in effect for most of the marine
  area today.

- Small Craft Advisories linger into tomorrow for the coastal
  waters due to elevated seas.

- Another round of Small Craft Advisory conditions is possible
  this weekend into early next week.

Early morning sfc analysis shows an area of strong high pressure to
the NE and an area of low pressure (formerly PTC 8) to the SW over
the Carolinas. The tight pressure gradient between these features
has allowed for elevated winds and waves to continue. Latest obs
reflect easterly winds of 15-25kt with a few gusts up to 30kt. Winds
have been showing a downward trend, however, over the southern
coastal waters/Currituck sound. Seas there are slowly diminishing as
well, but are still up around 7ft. Elsewhere, seas are 6-8ft and
waves are generally 3-5ft. The sfc low will weaken as it lifts to
the NW today, allowing the pressure gradient to relax and winds to
gradually improve from S to N through the day and into tonight.
Winds will be 15-20kt (occasionally 20-23kt) through the afternoon.
Should see greater improvement after sunset as a weak area of
secondary low pressure passes over the coast overnight. By ~midnight
tonight, winds will be down to 10-15kt, which will continue through
Wednesday. Seas will improve through Wed, but the onshore winds will
make this improvement gradual. Expect 5ft seas will linger in the
northern waters through most of Wednesday, so have extended the SCAs
there accordingly.

The coastal low then exits to the NE as high pressure builds in from
the NW. Winds flip around to the N/NW for Thurs-Fri at ~10kt. Should
get a couple of days of sub-SCA conditions in for the end of the
week. Seas will be 3-4ft, waves 1-2ft. Could potentially see more
SCAs over the weekend due to a tight pressure gradient between high
pressure pushing in from the N and low pressure just offshore.

&&

.TIDES/COASTAL FLOODING...
As of 445 AM EDT Tuesday...

Astronomical tides will continue to increase today with the
approach of the next full moon. Higher astro tides along with
prolonged onshore flow will lead to nuisance to low-end minor
tidal flooding across much of the area along the bay and tidal
rivers. Locations along the upper bay and Rappahannock/Potomac
rivers are more likely to reach minor flood thresholds with the
afternoon high tide than elsewhere. Will therefore let the
Coastal Flood Advisories for Northern Neck and the bay side of
the MD Eastern Shore continue through the afternoon as planned.
Regarding the coastal flood statement along the Albemarle Sound-
water levels have so far remained below flood thresholds.
However, levels do show a slight upward trend, so will continue
to monitor and keep the statement in place for now.

Additional advisories/extension of advisories will likely be
needed through the end of the week due to extended periods of
onshore flow and high astro tides. So far, moderate flooding is
not expected.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...Flood Watch until 7 PM EDT this evening for NCZ012>017-030>032-
     102.
VA...Flood Watch until 1 AM EDT Wednesday for VAZ064-075>078-
     080>090-092-093-095>098-511>525.
     Coastal Flood Advisory until 4 AM EDT Wednesday for VAZ075-077.
     Coastal Flood Advisory until 6 AM EDT Wednesday for VAZ076-078-
     085-522.
     Coastal Flood Advisory until midnight EDT tonight for VAZ089-
     090-093-095>100-524-525.
MARINE...Small Craft Advisory until 10 PM EDT this evening for ANZ630-
     631.
     Small Craft Advisory until 4 AM EDT Wednesday for ANZ632-634.
     Small Craft Advisory until 1 AM EDT Wednesday for ANZ638.
     Small Craft Advisory until 6 AM EDT Thursday for ANZ650.
     Small Craft Advisory until 1 AM EDT Thursday for ANZ652-654.
     Small Craft Advisory until 1 PM EDT Wednesday for ANZ656-658.

&&

$$

SYNOPSIS...HET
NEAR TERM...HET
SHORT TERM...AJB/HET
LONG TERM...RMM
AVIATION...RMM
MARINE...AM
TIDES/COASTAL FLOODING...