475
FXUS61 KAKQ 050122
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
922 PM EDT Sat May 4 2024

.SYNOPSIS...
Off and on showers are expected to continue through Sunday night.
Summerlike conditions return to the area for next week with
daily chances of showers and storms.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
As of 920 PM EDT Saturday...

Key Messages:

-Scattered to widespread showers and perhaps an isolated
 thunderstorm are expected in most areas west of the Chesapeake
 Bay overnight.

-Localized rainfall totals of over an inch are possible, but
 most areas will see 0.25-0.5" (with little to no rain near the
 Atlantic coast and on the eastern shore).

Evening wx analysis shows that the backdoor cold front that pushed
to the south of the area yesterday is very slowly starting to move
back to the north and is centered from north-central NC to Hampton
Roads. Meanwhile, a subtle shortwave is tracking ENE across wrn NC.
Locally, showers and isolated tstms are ongoing near and just to the
north of that boundary across srn VA/NE NC, with showers and drizzle
on the cool side from the RIC Metro to central VA Piedmont (where
temps are in the mid 50s-60F). That boundary will gradually move
back to the north tonight through Sun, while the shortwave in wrn NC
will push ENE toward the region tonight. Widespread showers are
expected to develop/move into most areas west of the bay overnight,
with a slight chc of a tstm across southern portions of the FA.
Could see localized rainfall totals of 1"+, but areal average QPFs
are 0.25-0.5", with little to no rain expected on the eastern shore
and near the Atlantic coast. Lows will be in the lower to mid 50s
across the N, and in the lower to mid 60s in the S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
As of 400 PM EDT Saturday...

Key Messages:

- Continued unsettled, but warmer, Sunday.

- More humid Monday/Monday night with showers and storms
  areawide.

The front (as a warm front) will move ENE and north of the area
Sun into Sun evening, shifting the low-level flow to the S. These
factors should act to scour out the dreary conditions. However,
still expecting showers and some tstms to redevelop for later
Sun morning into Sun evening (PoPs 30-70%). PoPs will diminish
later Sun evening into Sun night. Highs on Sun will warm into
the 70s across the region. Lows Sun night in the lower to mid
60s.

Upper heights begin building back N for Mon with high temps
warming into the upper 70s to lower 80s. Despite the warmer
temps, a lee trough is expected to develop in the aftn and
evening hours. Combined with an approaching shortwave from the
OH River Valley, showers and storms are expected to develop over
the higher terrain in the aftn, then slide eastward into Mon
evening/night. Mean LREF CAPE shows ~750 J/KG, but shear looks
to be rather weak. Therefore, the severe threat looks relatively
low, but cannot rule out a stronger storm or two. Soundings do
show a rather saturated atmospheric column (PWATS potentially
reach or exceed 1.5"), which could lead to some heavier
downpours. Dew points also increase into the mid to upper 60s,
so the humidity will make it feel more like early summer.
Shower/storm activity diminishes inland after midnight, but may
linger closer to the coast overnight. Lows Mon night mainly in
the lower to mid 60s.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 410 PM EDT Saturday...

Key messages:

-A summer-like pattern will bring unsettled conditions and
 above-normal temps Tuesday through Friday.

-There is the potential for severe weather mid to late week.

An unsettled, summertime pattern takes over from Tue through
Fri. A ridge aloft builds in by Tue aftn, then weakens slightly
starting Wed. The GFS and ECMWF both suggest stronger 500mb
flow of up to 50 kt by Wed aftn. Additionally, several waves of
weak shortwave energy will pass over the area. As of latest
guidance, the strongest of these looks to pass through Thu
ahead of an UL trough dropping into the Great Lakes. A stronger
system (i.e. cold front) will then cross the area Thu night into
Fri. These features along with plentiful daytime heating/instability
will allow for daily rounds of showers/tstms. Will be monitoring
this time period for severe weather given the support aloft and
steep mid-level lapse rates. The CSU Machine Learning Probabilities
have picked up on the aforementioned parameter space and suggest
at least a slight risk for severe weather Thu for the entire
area. Mainly dry weather will return for Sat. Highs will be in
the upper 70s to mid 80s Tue, in the mid 80s to lower 90s Wed
and Thu, in the upper 70s to lower 80s Fri, and in the lower to
mid 70s Sat.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
As of 730 PM EDT Saturday...

IFR CIGs still prevail at RIC/PHF this evening, with MVFR/VFR at
SBY/ORF/ECG. The backdoor cold front that crossed the area yesterday
will slowly lift back north as a warm front tonight into Sunday.
CIGs should improve to MVFR (with occasional periods of VFR) as
winds become SE-SSE after the front moves north of a given terminal.
It looks like IFR CIGs likely hang on until late morning Sun at RIC,
with improvement to MVFR possible at PHF by late tonight. In
addition, showers will once again overspread RIC tonight (but most
of this activity will likely remain west of the coastal terminals
through the night). Showers are likely at all terminals on Sun, with
isolated-scattered tstms possible during the aftn/evening.

Outlook...Sub-VFR conditions are expected at times from Sunday night-
Monday, due to an unsettled weather pattern. Sunday night should be
mostly dry, but more tstms are possible Mon aftn-late Mon evening.
A warmer, more summerlike pattern returns Tue through Thu, with
chances for storms each aftn/evening.

&&

.MARINE...
As of 340 PM EDT Saturday...

Key Message:

- Small Craft Advisories remain in effect for the Chesapeake Bay
  and lower James River through late tonight/early Sunday
  morning.

1030mb high pressure is centered over the Gulf of Maine this
aftn, with a stationary front in vicinity of the NC Outer Banks.
The wind is primarily E 10-15kt with guts up to 20kt, and
somewhat less S of Cape Henry in closer proximity to the trough.
Seas are ~4ft, with 3-4ft seas in the mouth of the Ches. Bay,
and 2- 3ft elsewhere in the Ches. Bay. The wind is expected to
increase to 15-20kt with gusts up to 25kt across the Ches. Bay
and lower James later this aftn through the early overnight
hours, before shifting to SE and diminishing slightly later
tonight. SCAs remain in effect for these zones. Seas are
expected to remain ~4ft, with 3-4ft seas in the mouth of the
Ches. Bay, and 2-3ft elsewhere in the Ches. Bay tonight.

The stationary front will lift back N as a warm front Sunday.
with the wind shifting to SE/SSE. A SSW wind returns for Monday
through the middle of next week (but likely remain sub-SCA).
Southerly flow should prevail through most of next week with the
next backdoor cold front possible some time Friday.

&&

.TIDES/COASTAL FLOODING...
As of 905 PM EDT Saturday...

Key Messages:

- Have extended a Coastal Flood Advisory for the northern Neck
  through Sunday night for widespread minor flooding.

- Coastal Flood Statements remain in effect for the bayside of
  the Maryland eastern shore, with an upgrade to a Coastal Flood
  Advisory likely for additional rises late Sunday into Monday
  morning.

The pattern of an elevated E wind shifting to the ESE to SE by
tonight favors going above ETSS guidance across the Northern
Neck. As such, a Coastal Flood Advisory remains in effect in
this area through Sunday night. A Coastal Flood Statement
continues for the bayside of the MD eastern shore to cover
nuisance flooding through late tonight. Water levels further
increase here later Sunday into early Monday with an upgrade to
a Coastal Flood Advisory likely as a SSE wind will tend to focus
the highest departures here by that time. A Coastal Flood
Statement is in effect for locations on the west shore of the
middle Bay to cover nuisance flooding for the next high tide
cycle. It still appears that other than locally moderate
flooding at Bishops Head, this event will peak in minor flood
category with the high tide cycle Sunday aftn into early Monday.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...Coastal Flood Advisory until 4 AM EDT Monday for VAZ075>078.
MARINE...Small Craft Advisory until 7 AM EDT Sunday for ANZ630>632-634.
     Small Craft Advisory until 4 AM EDT Sunday for ANZ638.

&&

$$

SYNOPSIS...TMG
NEAR TERM...ERI
SHORT TERM...AM/TMG
LONG TERM...AM/TMG
AVIATION...ERI
MARINE...AJZ/LKB
TIDES/COASTAL FLOODING...AKQ