950
FXUS61 KAKQ 171951
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
351 PM EDT Fri May 17 2024

.SYNOPSIS...
Showers become widespread across the piedmont later this
evening, and slowly shift east overnight, remaining likely
through most of Saturday. The widespread rain will shift south
later Saturday night into Sunday, though at least light rain or
drizzle will still be possible. Dry weather returns Monday,
with a warming trend leading to a more summerlike pattern by the
middle of the week.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 330 PM EDT Friday...

Key Messages:

- Rain becomes more widespread tonight, from W to E (reaching
  the coast between 06-12Z). Locally heavy rainfall possible
  (mainly west), with a Flood watch in place over portions of
  the Piedmont.

- Showers continue Saturday with below normal high temperatures,
  additional heavy rain possible.

Sfc high pressure is centered across eastern Canada and
northern New England, ridging into the local area. Low clouds
and onshore flow continue along the coast a it remain mostly
cloudy over the entire area. Some light showers have moved into
NW portions of the FA. Temperatures are rather cool along the
coast (in the 60s), with low-mid 70s well inland. Have backed
off on any tstm chances over the next few hrs, then may see some
isolated/embedded storms mainly across the southern piedmont
after 21-22Z.

A southern stream shortwave will advance across the Deep South this
evening into tonight. Overrunning moisture spreads over the area
from W to E late tonight, with increasing chances for showers and
isolated storms (PWATs increase to 1.6-1.8"). The tstm potential
should be confined mainly W of I-95 and along and S of route 460,
removed from the cooler/less stable marine airmass closer to
the coast. Relatively mild tonight with lows around 60F, except
in the low- mid 50s on the eastern shore. There remains some
disagreement among the CAMs as to where the highest coverage and
QPF sets up. As of now, HREF probability- matched mean QPF
fields highlight the highest QPF W of I-95 and especially in the
I-64 corridor NW of RIC. Locally heavy rainfall is likely in
spots. This is also where the highest PoPs have been drawn in.
WPC has a slight ERO just NW of our wrn CWA line, with a
marginal across our W/NW counties. The axis of heavier rain may
shift eastward near and after sunrise Saturday, with some signal
for heavy rainfall also across srn portions of the area with
some elevated instability sliding through.

Weak sfc low pressure tracks just S of the area Sat afternoon. While
moist WSW flow aloft and deep lift continues over the region in
advance of the approaching upper-level system, coverage of rainfall
may be hit or miss later Saturday morning into early/mid aftn
as earlier day rain/convection limits any aftn destabilization.
Current thinking is most of the heavier showers and storms stay
to our W or SW, though cannot rule out a few storms clipping our
SW counties. High temps Sat will remain below normal w/ the
onshore flow and are in the 60s N to low 70s over the far south.
The vast majority of the QPF falls tonight through Saturday and
totals of 0.25-0.50" are expected on the eastern shore,
0.50-1.00" over most of the rest of the CWA, with 1.00-1.50"
(local amounts in excess of 2.00" possible) in the piedmont. The
Flood watch remains in effect for portions of the VA Piedmont.
Some heavy rainfall and 1-2" is possible over areas w/ low 3-
and 6-hr flash flood guidance (where 3-5" of rain fell earlier
this week). Did not expand the Watch given a general downward
trend in QPF and with a lot of uncertainty/spread in the HREF
means. For instance, in areas with a median amount of
1.00-1.50" the 25th percentile has less than 0.75".

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 330 PM EDT Friday...

Key Message:

- The more widespread rain and any additional heavy rain threat
  shifts S of the area after Sat evening.

- Dreary weather and a chc for additional showers are expected
  Sunday across the south, with drier WX later over the north.
  High temperatures will remain below normal.

the 12Z/17 models generally show high pressure to north slowly
building south Sat night through Sunday, as sfc low pressure
moves east across the Carolinas. Still enough upper level
support for likely PoPs south and chc PoPs elsewhere Sat night,
with some additional moderate to locally heavy rainfall possible
over far southern VA and NE NC. By Sunday, PWATs drop off to
<1.50" even in the south, with only the far southern areas expected
to see 0.10" or more of additional QPF. Total QPF for this
system will average 0.50"-1.00" over much of the CWA, with
1.00-1.50" and locally higher amounts possible in the piedmont
and over extreme SE VA and NE NC (as some additional higher QPF
affects SE VA/NE NC into Sat night).


Sunday PoPs have been lowered to 40-50% in NC, and to 15-30%
elsewhere. Note that even with this continued trend to a drier
solution for Sunday, it will still be relatively unpleasant with
increasing NE winds, cloudy skies, and highs only in the 60s.
There could be some partial clearing over the northern 1/2 of
the CWA Sun aftn so highs may reach to around 70F. Partly cloudy
NW to mostly cloudy SE Sun night with lows in the 50s.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 325 AM EDT Friday...

Key Messages:

- Temperatures remain below normal Monday with mostly cloudy
  skies along the coast.

- Dry/sensible weather expected Tuesday and Wednesday with
  temperatures trending much warmer.

Low pressure gradually shifts offshore Monday, though an additional
low may develop S of the upper feature offshore. High pressure also
nudges south into the Mid-Atlantic. NE flow is still expected
(breeziest across southern coastal areas), keeping temperatures
below normal. The low levels may dry out some W of I-95, allowing
temperatures to warm into the 70s. Upper 60s are expected again
along the coast. The majority of the area stays dry with just a
slight chc of shower along the coast. Lows Mon night in the 50s with
some upper 40s possible well inland.

Stacked sfc and upper low meanders offshore of the Carolinas Tuesday
before finally being kicked out out to sea Wednesday and Thursday.
Dry Tuesday with warmer temps in the mid/upper 70s inland and lower
70s at the coast. The warming trend continues Wed into Thu with 80s
making a comeback. Even could see some upper 80s for some areas Thu.
There is decent agreement among the global models that a cold front
will cross the area later Thursday afternoon. Will have a chc of
showers and storms over most of the area. A little cooler behind the
front to end the week. Overnight lows will be in the 50s Tue night
and 60s for the remainder of the week.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
As of 200 PM EDT Friday...

Onshore flow has led to low clouds pushing inland today, with
widespread MVFR CIGs. There are some mainly light showers moving
in from the west. Trends show that most places will see rising
CIGs into this evening allowing for mainly VFR conditions, with
E-NE 5-10 kt winds prevail. Scattered to numerous rain showers
move in from the W later in the evening/overnight, with flight
restrictions are likely in both CIGs and VSBY, with heavy rain
possible.

Outlook: A slow moving low pressure system will bring showers,
and degraded flight conditions Saturday, with at least a chance
for showers (and flight restrictions likely) into Sunday. Mainly
dry by Sun night with a few lingering showers in the SE. Dry
Mon-Tue.

&&

.MARINE...
As of 200 PM EDT Friday...

Key Messages:

- Sub SCA conditions expected this evening and overnight.

- Increasing NE wind and waves for the weekend. Small craft
  advisory conditions are expected over the entire marine area
  later Saturday and through SUnday. Wind gusts to 20 to 25 kt
  and seas building to 4 to 7 feet.

Weak high pressure is centered along the coast from the
Carolinas to New England. The wind was generally NE at or below
15kt this afternoon, with seas 3-4ft and waves in the Bay
mainly 1-2ft. An area of weak low pressure will slowly
approach from the west Saturday as high pressure remains over
New England resulting in a tightening pressure gradient late Sat
into Sun. The wind will remain NE overnight tonight around
5-10kt, becoming E to SE 5-10 kt by morning. E winds increase to
10-15kt through the morning hours with 15 kt potentially
gusting to 20 kt mid to late Saturday afternoon. Seas will
mainly be 3-4ft tonight into Saturday then build late Saturday
into Sunday.

Low pressure becomes more organized off the Carolina coast Saturday
night into Sunday, before very slowly pulling away from the coast
through Monday. Meanwhile, high pressure slowly builds in from the
N. A NE wind is expected to range from 15-20kt with gusts to 25
kt (strongest for the lower Bay and ocean) with seas building
to 4-5ft N and 5-6ft S and 3- 5ft waves in the mouth of the Bay.
SCAs are likely during this time period for the lower
Bay/ocean, with less confidence of SCA conditions elsewhere.
High pressure builds across the Mid-Atlantic coast Tuesday into
Wednesday as weak low pressure lingers off the Southeast coast.

&&

.HYDROLOGY...
As of 320 PM EDT Friday...

Flood Warnings remain in effect for Nottoway River near Stony
Creek for minor flooding. Lawrenceville crested last night and
has now fallen below flood stage. Stony Creek remains in flood
and is expected to crest tonight. See FLSAKQ for additional
information.

While uncertainty remains with respect to rainfall amounts and
exact placement over the weekend, median expected amounts are 1.00-1.50"
range across area basins over the weekend. Latest forecasts
indicate these amounts will lead to a secondary rise in water
level late in the weekend/early next week, but that most places
stay just below Minor Flood thresholds, though will need to
monitor as a slight over-performance would lead to additional
flooding.


&&

.TIDES/COASTAL FLOODING...
A Coastal Flood Advisory is in effect for the upper Bay and
portions of the Northern Neck for the high tide this evening.
Two strong flood tides with very weak ebbing is resulting in a
piling up of water from Windmill Point north. Minor tidal
flooding is likely at Lewisetta and Bishops Head this evening.
Water levels should drop with stronger ebbing expected overnight
before the Saturday morning high tide.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...Coastal Flood Advisory from 8 PM this evening to 2 AM EDT
     Saturday for MDZ021.
NC...None.
VA...Coastal Flood Advisory from 8 PM this evening to 2 AM EDT
     Saturday for VAZ075-077.
     Flood Watch through Saturday morning for VAZ048-060-061-
     066>068-509.
MARINE...None.

&&

$$

SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...LKB/SW
LONG TERM...LKB/SW
AVIATION...LKB/SW
MARINE...AJZ/JAO
HYDROLOGY...
TIDES/COASTAL FLOODING...