875
FXUS61 KAKQ 181055
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
655 AM EDT Sat May 18 2024

.SYNOPSIS...
Widespread showers continue through early this afternoon, with a
few thunderstorms also possible across the south. The
widespread rain will shift south tonight 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 TONIGHT/...
As of 325 AM EDT Saturday...

Key Messages:

- Widespread rain showers expected through this morning. Locally
  heavy rainfall is possible and a flood watch remains in place
  over portions of the Piedmont.

- Showers continue into this afternoon, with a chance of
  thunderstorms mainly south of the NC/VA border.

Early morning analysis shows high pressure (centered over Atlantic
Canada) ridging S into the coastal Mid-Atlantic. Just to the E
(offshore), expansive, but weak, low pressure continues to
harmlessly spiral. In the upper levels, WSW flow continues ahead of
a srn stream shortwave currently located over the mid-South. Water
vapor imagery also shows a secondary impulse in the WV/srn PA
vicinity. Along with a sfc boundary/weak sfc low, this upper
disturbance is serving to focus moderate-heavy showers over most of
the Piedmont. Radar shows the heavier echoes gradually moving E,
though weak low and mid-level wind fields are favoring rather slow
movement of these showers. With 6z mesoanalysis showing 1.5-1.7"
PWATs (highest W/SW) and model-derived soundings showing a deeply
saturated moisture profile, heavy rainfall is possible in any
showers. Analyzed instability is very weak but any deeper shower
could produce a rumble of thunder. There is decent agreement among
the CAMs that the heavier rain gradually pushes E toward sunrise.
This lines up well with current trends seen on radar. Further S in
NC, additional (more scattered in nature) showers will also push
E/NE into NE NC and SE VA into the mid-morning. Highest QPF
continues to focus across W of I-95 and especially in our far wrn
tier of counties. This is where the flood watch continues through 10
AM. While aerial QPF is marginal for widespread flooding issues, any
slow-moving or stationary shower could quickly put down 1-2" in
a couple hours. This could lead to localized flooding concerns,
especially for areas that received significant rainfall earlier
this week.

Rain transitions closer to the coast in the late morning and early
afternoon. Thinking is the intensity trends down a bit (especially
from the Northern Neck into the eastern shore), while becoming more
"showery" in nature, as the higher PWATs become increasingly focused
S of the area. There remains some uncertainty heading into the
mid/late afternoon regarding coverage of showers and possible
storms. For the nrn half of the area, not expecting much
redevelopment due to lingering impacts from the morning
rain/convection and cool low-levels from the NE flow. Some sfc-based
instability may creep into far srn VA and NE NC which could favor
storms. CAMs generally focus most of the heavier activity just S of
our CWA and along a remnant Midwestern MCS boundary. The best chance
for storms in our CWA would be just S of the NC/VA border and
especially along the Albemarle Sound. SPC has a marginal risk for
severe for these areas, but thinking is best chance for svr is well
to our S given the meager instability (and decreasing) instability.
Elsewhere, just expecting scattered light rain or showers and
perhaps some drizzle. It certainly won`t feel like late spring with
cloudy skies and highs struggling to get out of the low-mid 60s for
most of the FA. Upper 60s or lower 70s are possible in interior NE
NC and S and W of US-460. Scattered showers continue into tonight
with the highest coverage over SE VA and NE NC. Overnight lows will
be in the low-mid 50s under continuing overcast skies. Becoming
breezy along the immediate coast with a tightening pressure
gradient.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 325 AM EDT Saturday...

Key Messages:

- Low chance for showers across SE VA and NE NC Sunday, with dry
  weather elsewhere. High temperatures will remain below normal,
  though may warm into the 70s for northern portions of the
  area.

- Partly to mostly cloudy skies and below normal temperatures
  Monday across coastal areas. Near-normal temperatures
  expected well inland.

Drying out Sunday as weak low pressure gradually moves ESE off the
Carolina coast. There may be quite a difference in weather Sunday
across the area as drier air attempts to filter into from the north
and the cooler maritime airmass persists across the SE and along the
coast. Thus, we may see some clearing for northern portions of the
area away from the immediate coast (especially in the later aftn
hrs). In response to this potential, the guidance is trending up
with temps across this area. Given looming uncertainty and the fact
that these airmasses are sometimes hard to scour out, will blend the
previous forecast`s highs w/ the NBM, which yields temps in the low
70s across the N (a couple degrees below NBM). However, temps could
certainly be warmer w/ 75th percentile highs approaching the mid
70s. Highs likely to stay in the 60s in SE VA/NE NC and along the
Atlantic coast (where it also remains breezy). PoPs also continue to
trend down, with just slight chc for the srn half of the area
(30% along the Albemarle Sound). Lows Sun night in the mid 50s.

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 across the SE, and slight below normal elsewhere. The
low levels dry out enough well inland, allowing temperatures to warm
into the mid-upper 70s. Upper 60s are expected along the coast. The
majority of the area stays dry with PoPs below 20% areawide. Lows
Mon night in the 50s with some upper 40s possible well inland.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 325 AM EDT Saturday...

Key Messages:

- A substantial warming trend is expected Tuesday through
  Thursday with mainly dry weather.

- Thunderstorm chances return Thursday afternoon and again
  Friday afternoon, with some stronger storms possible.

Low pressure gets pushed offshore rather quickly Mon night,
with upper level ridging moving in by Tue. As such, much warmer
temps are expected midweek, with highs Tue in the upper
70s/lower 80s inland and in the low-mid 70s at the coast. The
warming trend continues Wed into Thu with mid/upper 80s making a
comeback. An isolated shower is possible across the NW Wed
night w/ a shortwave sliding through the ern Great Lakes.
However, vast majority of the moisture stays well to our NW.
There is decent agreement among the global models that a cold
front will cross the area in the later Thursday/early Friday
timeframe. Will have a chc of showers and storms over most of
the area. CAPE fields from the GFS/ECMWF show impressive
instability so could see some stronger storms. A little cooler
behind the front to end the week, though will need to watch
another disturbance ejecting out of the Plains Friday into
Saturday. Depending on the track of the sfc feature, will again
need to monitor for some stronger storms. Overnight lows will be
in the 50s Tue night and 60s for the remainder of the week.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
As of 650 AM EDT Saturday...

As of 11/12z, conditions continue to oscillate at all
terminals. SBY is VFR, RIC has been bouncing across 3 flight
categories, and ORF/PHF/ECG are mainly MVFR. Generally MVFR
CIGs this morning and then IFR by the aftn today (SBY may stay
MVFR for most of today). Coverage of showers may lower some
later in the aftn, but IFR-LIFR CIGs and potentially some
drizzle will keep flying conditions less than ideal. Degraded
VSBY in rain/drizzle is also likely. Showers/storms redevelop
late this aftn/evening, mainly S of the NC/VA border. Have
therefore included VCTS at ECG from 22z-01z. E-NE winds are
light this morning, with 5-10 kt winds prevailing for the
remainder of the period.

Outlook: At least some chance for showers (and flight
restrictions likely) into Sunday morning, with the best chance
at srn terminals. Mainly dry by Sun afternoon and night with a
few lingering showers in the SE. Dry Mon-Tue.

&&

.MARINE...
As of 325 AM EDT Saturday...

Key Message:

- Increasing NE wind and seas for the weekend. Small craft
  advisories will go into effect for southern portions of the
  marine area later tonight.

Weak high pressure is centered in vicinity of the Mid-Atlantic coast
early this morning, with weak low pressure centered well inland and
slowly approaching from the W. The wind in mainly E to NE at 5-10kt
with seas 3-4ft. Low pressure will track ESE across NC today and
become more organized off the Carolina coast tonight into Sunday,
before very slowly pulling away from the coast through Monday.
Meanwhile, high pressure slowly builds in from the N. The wind is
expected to become E 10-15kt today, and then become NE by tonight
into Sunday ranging from 10-15kt N to 15-20kt with gusts to 25kt S.
Seas build to 4-5ft N to 5-6ft S (potentially 6-8ft if the wind
reaches 20-25kt). SCAs will go into effect later tonight from Cape
Charles S for the ocean, the mouth of the Bay, and the Currituck
Sound. High pressure builds across the Mid-Atlantic coast Tuesday
into Wednesday as weak low pressure lingers off the Southeast coast.
High pressure slides offshore later in the week with the wind
becoming SSW but remaining sub-SCA. Seas gradually subside to 3-4ft
by Monday night/Tuesday, and then 2-3ft by midweek.

A moderate risk for rip currents continues for today, with moderate
for the northern beaches Sunday, and high for the southern beaches
due to increasing NE flow and building seas.

&&

.HYDROLOGY...
As of 325 AM EDT Saturday...

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.

Latest forecasts indicate rainfall amounts from today 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. Will still need to monitor as a slight over-
performance would lead to additional flooding.

&&

.TIDES/COASTAL FLOODING...
As of 325 AM EDT Saturday...

Tidal anomalies have dropped a few tenths of a foot across the
middle Chesapeake Bay and tidal Potomac and Rappahannock Rivers
in the wake of a modest ebb tide. Therefore, nuisance to minor
tidal flooding is largely not expected during the next high tide
cycle later this morning to mid-afternoon. However,
astronomical high tides will gradually increase over the next
several days, and this combined with increasing onshore flow
will result in nuisance to minor tidal flooding later this
weekend into early next week, particularly for the middle
Chesapeake Bay and tidal portions of the Rappahannock River and
southern shore of the tidal Potomac.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...Flood Watch until 10 AM EDT this morning for VAZ048-060-061-
     065>068-509.
MARINE...Small Craft Advisory from 4 AM to 10 PM EDT Sunday for ANZ633.
     Small Craft Advisory from 4 AM Sunday to 1 AM EDT Monday for
     ANZ634.
     Small Craft Advisory from 4 AM Sunday to 7 AM EDT Monday for
     ANZ656-658.

&&

$$

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