450
FXUS61 KAKQ 130712
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
312 AM EDT Mon May 13 2024

.SYNOPSIS...
Scattered showers are possible for the Eastern Shore this
afternoon as an upper trough exits the region. Dry and warmer
to start the work week before another round of showers and
storms returns to the region Tuesday and Wednesday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 925 PM EDT Sunday...

Key Messages:

- Drying out tonight with some patchy fog possible on the
  eastern shore.

- Warmer and remaining dry for Monday.

An upper level trough is pushing off the Mid-Atlantic coast
this evening. Mostly clear aside from some scattered lingering
clouds over the MD Eastern Shore. Drying out overnight with a
clearing sky along the MD coast behind the departing trough.
Some patchy fog will again be possible late, this time on the
eastern shore and perhaps also over the peninsulas of eastern VA
and the interior tidewater. Early morning low temps fall into
the mid to upper 40s inland (some lower 40s possible for the NW
Piedmont), and the upper 40s to low 50s along the coast.

High pressure over the coastal plain slides offshore on Monday,
bringing warmer temperatures and dry conditions (briefly) back
to the region. High temps climb back into the 70s to low 80s.
Clouds start to increase by late in the afternoon from the SW
ahead of our next system.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
As of 330 PM EDT Sunday...

Key Messages:

- Increasing clouds Monday night, with showers developing late
  over inland areas.

- Next system moves in Tuesday with showers and thunderstorms.
  Widespread severe weather is not expected.

- Showers and a few storms linger on Wednesday before moving
  offshore overnight.

Rain chances quickly ramp up after midnight Monday night/early
Tuesday and into the day on Tuesday. A closed upper low over the
mid-Missouri Valley translates east into the Western TN Valley
Monday night, with the system slowing and lingering across the
TN Valley through midweek.

Overrunning moisture pushes into the piedmont region west of
RIC in the early morning hours Tuesday, reaching the I-95
corridor by midday, and the coast by mid- afternoon.
Kinematics and relatively weak deep- layer shear would indicate
only a modest chance for storms on Tuesday, with the overall
severe threat even lower. However, will maintain a thunder
chance through the afternoon on Tuesday over SW sections and
along the SE coast into later Tuesday evening. QPF through Tue
night between 3/4" and 1" of additional rainfall, with locally
higher totals possible. Best chances for periods of locally
heavy rainfall will be across south central and southeast VA
into northeast NC Tue night, where secondary low pressure looks
to develop Tuesday aftn, lifting a warm front across the region
Tuesday evening. Better area of IVT and PW values AOA 1.5-1.75"
(near climo daily maxes) then look to stream NNE across our SE
coastal plain Tuesday evening, with showers and storms forecast.
For its part the CSU machine learning probs do show a marginal
risk area for its ERO forecast, which has been matched by WPC
for day 3 (Tuesday).

Rain briefly tapers off early Wednesday morning, especially
across the S/SE, as mid-levels briefly dry out. However, we
never really dry out lower levels through this period. This
likely portends continued overcast/substantial cloud cover and
light rain throughout Wednesday, as the closed low to the west
opens up and the surface reflection weakens as it crosses the
central/southern Appalachians. Precipitation character remains
a bit more stratiform through the day for most. However, chances
for storms do increase a bit over NE NC and perhaps into Hampton
Roads by afternoon as the weakening upper low approaches. This
allows for a period of increased deep-layer shear (25-35 kt)
along with some decent instability (LREF does show 500-750 J/kg
of CAPE by afternoon) in the pseudo warm sector across the SE.

As high pressure builds to the north, the weakening surface low
crosses the area Wed night, with the positively-tilted upper
trough lingering over the area into Thursday. Given this timing,
Wednesday night would then feature diminishing rain chances and
drier air filtering into the region. Kept highs in the 70s for
much of the area on Wednesday, with some lower 80s across the SE
coast. Lows Wed night in the 50s to near 60.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 330 PM EDT Sunday...

Key Messages:

-Continued warm late this week with increasing chances for showers
 and storms later Friday and Saturday.

High pressure builds in briefly on Thursday but another system
approaches on Friday with another chance for scattered showers
and storms, though the 12z suite of models is notably slower
with returning moisture back into the local area, and have
accordingly pushed PoPs a bit lower with this forecast package.
High temps remain in the 70s to low 80s on Thursday and Friday
with low to mid 80s on Saturday. Overnight lows continue around
60 degrees.

&&

.AVIATION /07Z MONDAY THROUGH FRIDAY/...
As of 755 PM EDT Sunday...

Weak low pressure is pushing off the coast as of 00z. VFR with
a light NE wind of 5-10kt, and only some SCT but dissipating
clouds around 6-8kft at SBY. Weak high pressure builds over the
region tonight. The wind will become calm to very light out of
the E tonight. Patchy fog is possible late tonight with the best
chc at SBY. The current forecast has prevailing IFR vsby at SBY
07-11z, and tempo MVFR vsby at PHF 08-11z. Brief MVFR vsby is
possible at ORF and ECG as well. High pressure slides offshore
Monday. Sunny and VFR with a SSW wind inland and SE along the
coast with speeds generally at or below 10kt.

Low pressure returns Tuesday into Wednesday bringing showers,
periodic flight restrictions, and possibly a few tstms.
Conditions gradually improve Thursday into Friday.

&&

.MARINE...
As of 310 AM EDT Monday...

Key messages:

-SCAs have been issued for the Chesapeake Bay from this evening
through early Tuesday morning for a brief period of elevated S to SE
winds.

-Additional SCAs are likely ahead of a low pressure system Monday
Tuesday into Wednesday morning

High pressure is centered near the waters early this morning with
light E winds and ~3ft. The high gradually shifts offshore today,
and winds then increase out of the S-SE (to ~15kt by late aftn) as
the pressure gradient tightens on the back side of the high.
Confidence in seeing a brief period of low-end SCA conditions on the
bay has increased this evening-early Tue AM, and local wind probs
now show a 70-90% chc of sustained 18kt winds between 6 PM today-2
AM Tue. Went ahead and issued SCAs for the bay that is in effect
from 6 PM through 1-4 AM.

S winds briefly diminish to 10-15kt Tuesday AM. However, a low
pressure system will approach the area on Tuesday before crossing
the area from west to east late Tuesday night/early Wednesday. The
pressure gradient will increase ahead of the system by Tue
aftn/evening, allowing S winds to increase to around 20kt (and
remain elevated through most of Tue night). Local wind probs
continue to show an 80-100% chc of 18kt winds on the bay Tue night.
Wind gusts are expected to be right around the 25kt threshold on the
ocean (and local wind probs for 25kt gusts are only 30-60% for a few
hrs Tue night), but seas should build to 5ft by Tue night.
Therefore, SCAs appear likely for the bay and ocean (and perhaps the
Lower James/Currituck Sound) with this system. Sub-SCA conditions
are expected behind the system Wed night-Thursday (w/ N-NE winds
near 15kt and seas subsiding to ~4ft). Waves on the bay will be 1-
3ft through most of the period (although 4ft waves are possible Tue
night).

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory from 6 PM this evening to 4 AM EDT
     Tuesday for ANZ630-631.
     Small Craft Advisory from 6 PM this evening to 1 AM EDT
     Tuesday for ANZ632-634.

&&

$$

SYNOPSIS...MAM/RHR
NEAR TERM...AJZ/MAM
SHORT TERM...MAM
LONG TERM...MAM/RHR
AVIATION...AJZ
MARINE...ERI