120
FXUS61 KAKQ 200717
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
317 AM EDT Mon May 20 2024

.SYNOPSIS...
High pressure settles over the region today, favoring dry
weather. A summerlike pattern develops by the middle of the
week. A cold front approaches from the northwest Thursday with
daily chances for showers and storms to end the week and into
the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 255 AM EDT Monday...

Key Messages:

- Dense fog is expected over the Piedmont through sunrise this
  morning.

- Less clouds overall today with warmer temps inland and
  cooler/cloudier conditions continuing at the coast.

High pressure has settled over the area this morning. Weak flow
inland and moist low-levels is allowing fog to develop and expand.
Nighttime microphysics channels and obs showing the densest fog as
of 06z/2 AM in the I-95 corridor. This should expand westward and
grow even more widespread closer to sunrise. Have issued a broad SPS
for now, but may end up needing a dense fog advisory at some point.
Most guidance scours the fog out by 8-9 AM and this seems
reasonable.

For the rest of morning and aftn, the high will remain near the area
with ridging slowly expanding to our N/NW aloft. However,
weak/elongated low pressure offshore will keep a residual pressure
gradient and onshore wind near the coast. Similar to the previous
few days, this favors warmer temps inland and cooler/cloudier
conditions at the coast. Still, expect there to be less clouds
overall and we could even see some full sunshine W of the Chesapeake
Bay in the later afternoon. Highs will be in the upper 70s to around
80F W of I-95, mid 70s further E but away from the water, and upper
60s/low 70s along the coast. Dry wx is expected areawide. A cloud
deck again spreads westward overnight, with perhaps some
additional fog developing. Lows tonight in the low-mid 50s.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
As of 255 AM EDT Monday...

Key Message:

- Dry Tuesday and Wednesday with a noticeable warming trend.

Relatively quiet conditions forecast for the first half of the week
as an UL ridge builds over the eastern CONUS and the sfc high over
Canada shifts south and offshore to our E/SE. Onshore flow will
continue through Tuesday, however, so coastal areas will remain
slightly cooler relative to inland locations to start. Tuesday will
have highs in the low-mid 80s inland and low-mid 70s at the coast.
Much warmer Wednesday with highs in the mid-upper 80s for most, with
upper 70s or lower 80s at the immediate coast. Lows will be in the
50s Tue night and 60s Wed night. Skies will average mostly
sunny/clear.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 255 AM EDT Monday...

Key Messages:

- A cold front crosses late in the week, bringing chances for
  showers and thunderstorms. A few storms could be strong to
  severe.

- Remaining warm, but unsettled, for Friday into the weekend.

The weather in the extended period looks to resemble a summerlike
pattern with diurnal chances for showers/storms. To start the
period, a potent trough will slide from the central Plains into the
Great Lakes region. At the surface, an associated cold front will
advance S/SE toward the region early Thursday. The guidance is in
decent agreement regarding the timing of the FROPA, with the latest
consensus favoring the later afternoon and early overnight period
Thursday. PoPs ramp up across the W/NW during the day and shift E/SE
into the evening. Generally, the GFS is a little slower than the
ECMWF. At least moderate surface-based instability is forecast
across the region in advance of the FROPA so thunderstorms look like
a decent bet. While still a few days away, the synoptic pattern
could favor some strong-severe storms given increasing mid-upper
level flow with the trough passing to to our N. Machine learning
methods are beginning to pick up on this potential so something to
keep an eye on. The area isn`t outlooked from SPC at this point.
Beyond this, the front looks to stall over NC and just S of the FA
as it becomes parallel to the mid-upper flow. Uncertainty grows for
Friday and the weekend as a shortwave slides through the OH River
Valley under a building ridge. At least some precip potential is
expected Friday, especially W of I-95. The degree of instability and
the placement of the sfc/upper features will dictate the
thunderstorm potential. At this time, will have the highest chances
for storms S and W of I-64. For those looking for a dry and
uneventful weekend weather-wise, next weekend doesn`t look to be
that. The remnant sfc boundary, lower sfc pressures, and moist,
southerly flow favors on and off showers and storms Saturday and
Sunday.

For temps, Thursday looks very warm or hot. Highs in the upper 80s
to around 90F inland and mid-upper 80s near the coast. With the
front weakening on its approach, Friday will only be slightly cooler
with highs in the low-mid 80s generally. The weekend temps won` be
as chilly as this past weekend, but still cooling off into the upper
70s or low 80s. Sunday may be a few degrees warmer. Overnight lows
will be in the 60s through the extended period.

&&

.AVIATION /07Z MONDAY THROUGH FRIDAY/...
As of 135 AM EDT Monday...

A deck of lower clouds is noted across ern VA this morning,
impacting RIC, PHF, and ORF. Additionally, patchy fog has
developed, mainly from I-95 and points W. The VSBY at RIC has
recently below to 1/2 SM and expect additional fluctuations
here. Otherwise, expecting the fog to become more widespread
as we approach sunrise, but should only be an operational
problem at RIC. Another lower deck of clouds is also expected
to move off the ocean in a few hrs. Thinking is this should be
mainly lower CIGs (IFR- LIFR possible) and not reduced VSBY.
However, cannot rule out VSBY issues at SBY/ORF/PHF/ECG,
especially in the 10-13z timeframe. Improvement is expected
later this morning and aftn, with clearing skies. Lower clouds
and CIGs (likely MVFR) remain along the immediate coast. Winds
are light and variable away from the coast this morning and
become 5-10 kt inland and 10-15 kt at the coast this aftn.

Outlook: Lower CIGs may again expand in coverage tonight, with
flight restrictions possible. Dry Tue and Wed w/ VFR.

&&

.MARINE...
As of 315 AM EDT Monday...

Key Messages:

-All Small craft advisories have been or will be discontinued by 4
AM.

- Generally quiet marine conditions starting tonight and continuing
for much of the week.

1024mb high pressure is centered over Atlantic Canada early
this morning and extends to the SW into the Mid-Atlantic region.
Meanwhile, low pressure linger off the Southeast coast in
vicinity of the Gulf Stream. The wind is NE and generally 5-10kt
over the rivers, 10-15kt over the Ches. Bay, Currituck Sound,
and ocean north of Cape Henry, and 15-20kt for the ocean south
of Cape Henry in closer proximity to the stronger pressure
gradient. Seas range from 3-4ft north to ~4ft S. Similar
conditions will persist through mid- aftn as high pressure
remain anchored to our NE and as low pressure lingers well off
the Southeast coast. The remaining SCA off the Currituck Outer
Banks will be discontinued at 4 AM as seas are primarily
expected to remain below 5ft.

The wind is expected to remain onshore but diminish later this
aftn into tonight as high pressure builds in from the north.
This area of 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 tonight/Tuesday, and then 2-3ft by
mid to late week. A cold front approaches from the NW Thursday
and settles into the region Friday into Saturday bringing a chc
of primarily aftn/evening tstms. Conditions will mainly be sub-
SCA with a potential for brief increases in wind and seas/waves
from tstms.

A high risk of rip currents is forecast today for the southern
beaches given a NE wind of 10-15kt and nearshore waves around 4ft. A
moderate risk of rip currents is forecast for the northern beaches
as the NE wind will be slightly lighter with 3-4ft nearshore waves.
By Tuesday, the rip forecast is moderate for the southern beaches
and low for the northern beaches as the wind relaxes and nearshore
waves gradually subside.

&&

.HYDROLOGY...
As of 315 AM EDT Monday...

Water is gradually moving downstream on the Nottoway River,
with Sebrell in minor flood stage early this morning. The river
will likely stay in flood into Tuesday before falling below
flood stage later Tuesday. Rainfall from yesterday may cause
localized rises in other rivers, but all remaining sites should
stay below action stage.

&&

.TIDES/COASTAL FLOODING...
As of 315 AM EDT Monday...

Tidal flooding is not expected during the next high tide cycle
later this morning into early aftn given the lower astronomical
high tide combined with a decent ebb tide. However, another
round of nuisance to minor tidal flooding will likely occur
during the higher astronomical high tide tonight as tidal
anomalies remain 1.0-1.5ft above astronomical, particularly for
the middle Chesapeake Bay and tidal portions of the Rappahannock
River and southern shore of the tidal Potomac. A similar
pattern will continue through midweek as the higher astronomical
high tides will remain elevated over the next several days.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...Coastal Flood Advisory until 5 AM EDT early this morning for
     MDZ021>023.
NC...None.
VA...None.
MARINE...Small Craft Advisory until 7 PM EDT this evening for ANZ658.

&&

$$

SYNOPSIS...SW
NEAR TERM...SW
SHORT TERM...AM/SW
LONG TERM...SW
AVIATION...RHR/SW
MARINE...AJZ
HYDROLOGY...AKQ
TIDES/COASTAL FLOODING...AKQ