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000
FXUS61 KAKQ 190749
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
349 AM EDT Sat Jun 19 2021

.SYNOPSIS...
High pressure lingers offshore through the weekend. A cold
front approaches from the northwest today and weakens north of
the local area on Sunday. Low pressure and associated tropical
moisture slowly builds south of the area over the weekend, and
will approach the area late Sunday into Monday. A cold front
crosses the area from Tuesday to Tuesday night.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 345 AM EDT Saturday...

Early morning wx analysis now shows high pressure well to our SE,
with a cold front stretching from the Great Lakes to the central
Plains. Fairly strong (for mid to late June) WNW flow aloft prevails
from the upper Midwest to the nrn Mid-Atlantic, with ridging over
the Desert Southwest. Potential Tropical Cyclone Three is now
positioned along the Gulf coast of LA. Radar and Satellite composite
imagery clearly shows multiple MCSs from SE Iowa to the Ohio Valley.
Locally, it is dry with SSW winds of 10-15 mph (with SCT-BKN high
clouds from the upstream convection. While the aforementioned cold
front is progged to sag SE today, it will stall well before coming
close to the area.

The flow aloft is forecast to become westerly and strengthen across
our area (especially north). The upstream MCS activity is expected
to decay as it moves eastward this morning and the high clouds over
the local area should thin out. It will be hot today as the low-
level flow becomes WSW with 850 mb temperatures of 17-19C. This
will allow temperatures to climb into the low-mid 90s (with 60s
dew points). Meanwhile, a lee trough will be developing even as
the cold front remains to our north. Isolated to scattered
tstms will likely develop just to our NW between 1 and 4 PM
afternoon in the vicinity of that lee trough, possibly aided by
remnant boundaries from the decaying MCS activity. Will have
25-45% PoPs across most of our northern areas from 18-00z, with
slight chc PoPs across interior south-central VA. Given the
strong sfc heating and steep low-level lapse rates, strong to
perhaps marginally severe wind gusts will be possible with the
storms that do develop. The highest severe threat is across nrn
portions of the FA where the stronger mid-level winds may allow
for a bit more organized storms. Additional convection may drop
E-SE across the MD Ern Shore (and perhaps the VA Nrn Neck)
after 00z Sun/8 PM into early Sun AM, so have maintained chc
PoPs through the first part of tonight over these areas. There
will be a marginal wind threat with these storms as well through
the evening, with the severe threat diminishing overnight with
the loss of surface heating. Isolated showers are possible
across the Ern shore after 06z/2 AM. Otherwise, it will become
increasingly muggy with lows in the 69-75F range.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
As of 345 AM EDT Saturday...

Sunday we`ll start to turn our eyes to the remnants of Potential TC
Three slowly lifting ENE or NE across the Deep South before reaching
SC by evening. The leading edge of the associated tropical moisture
will likely reach far srn VA and NE NC by Sunday evening, with PWAT
values increasing to 1.9-2.1". Locally, Sunday is still looking like
a rain-free day for most areas until late, with 15-30% PoPs after
18z. Isolated diurnally-driven convection is possible across most
areas west of the Ches Bay, with perhaps a bit more convection
across far srn VA and interior NE NC on the leading edge of the
richer moisture. The convection on Sunday is generally expected
to be sub-severe, but SPC has included parts of interior NE NC
in a Marginal Risk for severe wx (mainly due to a modest
increase in low-level speed and directional shear across far srn
portions of the area by late Sun).

The latest 00z/19 model consensus is now forecasting the remnant low
to track ENE to a position near the NC Outer Banks by Monday aftn.
This track would continue to point toward the heaviest rainfall
amounts remaining confined just to the south of the forecast area.
However, rain chances do steadily increase over the southern half of
the area (especially NE NC) from Sun night through Mon AM before
diminishing late Mon aftn/Mon evening as the remnant low moves
offshore. Have likely PoPs for all of NE NC, tapering to high
chc across Hampton Roads, with just a few showers expected in
central/nrn zones Sun night/Mon AM. The current forecast (which
largely follows an average of deterministic models and WPC QPF)
shows 0.2-0.8" of rain across Hampton Roads and NE NC. The
latest 00z/19 ensemble guidance (GEFS/GEPS/EPS) is only
painting 10-30% probabilities for >1" of rain from 2 am/06z Mon-
2 am/06z Tue across our far srn zones. Thus, while some locally
heavier totals from downpours are likely across SE VA/NE NC
coastal plain with wet-bulb zero heights aoa 13kft and PWs of
2.1-2.4" Mon morning into the aftn, the widespread flood threat
remains low across our area at this time (Flash Flood Guidance
values are generally 3-4" in 3 hours in NE NC). Very muggy
Sunday night with lows in the low-mid 70s. Highs Monday
generally in the mid-upper 80s SE and upper 80s-low 90s NW
(where there will be more sun).

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 345 AM EDT Saturday...

PoPs briefly diminish Mon night before attention then turns to
a potent shortwave that is progged to track ENE from the far
nrn Great Lakes to Quebec during the middle of next week. This
feature will very likely drag a fairly strong early summer cold
front through the region during the Tue-Tue night timeframe.
Have maintained likely PoPs during the day on Tue and will
continue chc PoPs into late Tue night across the SE to account
for this (for showers and tstms...more specifics to come as it
gets closer to the event given differences in timing between the
models). Highs Tue are forecast to be in the mid- upper 80s.
Cooler and much drier air then looks to return post- frontal on
Wed and Thu as high pressure settles into the area.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
As of 120 AM EDT Saturday...

Prevailing VFR conditions expected through the 06z TAF period.
SCT-BKN high clouds from upstream convection have overspread
most of the area. These high clouds will persist through much of
the morning, before thinning during the day today. SCT CU is
expected during the aftn, and isolated to scattered convection
is possible by mid to late aftn, with the best chances at
RIC/SBY, with PoPs aob 15% at PHF/ORF/ECG. Tstm chances increase
to 50% by late aftn/evening at SBY as convection to the west
approaches the MD Ern Shore (and potentially persists through
03-06z while pcpn chances diminish at the VA/NC terminals).
Still too early to add tstms to the TAFs though. Regardless,
brief IFR/LIFR VSBYs and gusty winds are likely in the
strongest storms.

Outlook...SW flow continues on Sun, with widely scattered late
day showers/tstms possible, especially NW of the VA/MD terminals
and south/southwest of ECG. Gradually more widespread
showers/tstms possible Monday and Tuesday, with sub-VFR
conditions likely in the heavier showers/tstms.

&&

.MARINE...
As of 300 AM EDT Friday...

SW winds cont to gust to SCA levels so will keep the headlines up
for the Bay and nrn coastal waters this morning. Droped SCA`s for
the rivers (except lwr James) and Currituck Sound as winds there are
below 20 kts. Gusty winds psbl in sct convection later today across
the Ches Bay and cstl wtrs as a s/w moves ese.

Will keep conditions below SCA levels Sun/Mon given the uncertainity
of the remnant tropical low progged to track south of the area. SW
winds 10-15 kt by Tue before a potent cold front crosses the region.
Could see minimal SCA`s with this feature for the mid week
period.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory until 10 AM EDT this morning for ANZ632-
     634-638-650-652.
     Small Craft Advisory until 7 AM EDT this morning for ANZ630-
     631.

&&

$$
SYNOPSIS...ERI/MAM
NEAR TERM...ERI
SHORT TERM...ERI/MAM
LONG TERM...ERI/MAM
AVIATION...ERI
MARINE...MPR