923
FXUS61 KLWX 071817
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
Issued by National Weather Service Mount Holly NJ
217 PM EDT Tue May 7 2024

.SYNOPSIS...
Daily chances for showers and thunderstorms look to continue through
Thursday as multiple fronts and waves of low pressure push across
the area. A potent cold front will bring an increased threat for
severe thunderstorms and flash flooding Thursday into Friday. Rain
chances decrease into the weekend with cooler temperatures and less
humidity as high pressure nears the region.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
A stalled front nearby will maintain unsettled weather conditions
heading into the middle of the workweek. Additional chances for
scattered showers and thunderstorms exists each afternoon although
the threat for organized severe weather threat remains low.

Scattered showers have developed in the vicinity of a remnant
frontal boundary already - indicating that the subsidence is too
weak to suppress convection this afternoon.

Convection will be of the pulse variety or loosely organized heading
into the afternoon and evening given abundant cloud cover/convective
debris over the region. More of a focus turns toward tonight as a
complex of storms will eject out of the Ohio River Valley. This
convection will be in it`s decaying phase as it works eastward.
Latest high res guidance indicates it will be mostly dissipated
by the time it gets to the I-81 corridor. However, heading into
Wednesday morning it could become a key player into how the
severe weather and hydro threat pan out Wednesday afternoon.

As for the severe threat today, it will remain fairly isolated
and confined to areas along and south of I-66/US-50. The
primary threat with storms today will be locally damaging winds
and isolated instances of flash flooding.

Highs today will push into the upper 70s and low 80s with a few more
filtered breaks of sunshine as things mix out heading into mid-
afternoon. Lows tonight will drop into the low to mid 60s with upper
60s over the Baltimore/Washington DC metro areas.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
On Wednesday, the instability in the atmosphere will be greater
given a few more breaks in the clouds due in part to west to
southwest flow. This will allow for some downsloping and
compressional warming especially east of the Blue Ridge. The
combination of downsloping flow and subtle subsidence in the wake of
the decaying MCS Wednesday morning may inhibit a widespread severe
threat especially along and north of the I-66/US-50 corridor. Even
with that said, scattered strong to severe storms remain possible
with the biggest concerns west of Blue Ridge and down across the
central VA Piedmont. The primary threat for storms will be damaging
winds and localized flash flooding. Large hail up to 1" in diameter
is also possible. Highs on Wednesday will soar into the mid to upper
80s across many lower elevation locations, with even a few areas
potentially hitting 90 degrees. The mountains will be in the mid to
upper 70s for the afternoon.

Mid-level troughing continues to deepen Wednesday night into
Thursday sending a potent cold front from the Ohio River Valley
toward the region. As a result, expect increasing shower and
thunderstorm chances late Wednesday night into Thursday morning as
another impulse of energy ripples through. Flash flooding could
become a concern here given the increased PWATS above climatology
for this time of year combined with antecedent conditions from
multiple rounds of showers and thunderstorms earlier in the week.

There will be a break between the morning precipitation and the
afternoon in which the atmosphere reloads especially in areas east
of the Blue Ridge. Instability parameters increase by Thursday
afternoon just ahead of the cold front, this will allow for the
potential for strong to severe thunderstorms to develop. Steep low-
level lapse rates support large hail along with damaging winds with
any of these storms. One caveat is that overall severe coverage may
be limited with the enhanced cloud coverage (from the morning hours)
prior to initiation, but will continue monitor given the
consistencies amongst SPC outlooks, CIPS analogues, and CSU
probabilities over the last few days. Main threats with storms
Thursday look to be damaging winds, large hail, and localized flash
flooding.

Afternoon highs Thursday will climb into the upper 70s to low 80s
for most areas. Northwest flow kicks in behind the cold front
Thursday night and will bring lows in the 40s along the Allegheny
Front with 50s further east.

A strong cold front will track through the area early Friday. While
shower and thunderstorm chances linger, the threat for severe
weather should diminish in the wake. After spending the previous
couple of days in the 80s, temperatures will certainly cool off to
finish out the work week. Friday`s forecast highs are likely
confined to the mid 60s to low 70s, locally falling into the 50s
across mountain locales. Depending on how quickly showers come to an
end, some late day clearing is not out of the question.
Northwesterly winds will be breezy at times with gusts up to 20 to
25 mph at times. Nighttime conditions will be cool with lows
dropping into the mid 40s to low 50s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...


This weekend will be a mixed bag given the cyclonic flow aloft. Each
day is forecast to carry a risk for some isolated to scattered
shower activity. High temperatures should be around 3 to 6 degrees
below average. That is, mid 60s to low 70s for most, but with mainly
50s for the mountain regions. Compared to the humidity earlier in
the week, it will feel much drier with dew points down in the 40s.
In between disturbances, there will likely be some periods of sun,
particularly by Sunday afternoon behind the next frontal system.
Expect temperatures to rebound into early next week as heights begin
to build.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
Predominantly VFR conditions continue with brief instances of
sub- VFR ceilings with any showers/thunderstorms that impact the
terminals through 00Z.

VFR conditions are most likely on Wednesday after early morning
showers and thunderstorms move further east. Coverage of
precipitation looks to be fairly limited on Wednesday. Light winds
today will likely turn more westerly by Wednesday, gusting up to 20
knots for the afternoon.

Widespread showers and thunderstorms are likely on Thursday, with
some strong to severe storms possible in the afternoon to evening at
all terminals. Outside of thunderstorm activity, VFR conditions are
likely though abundant cloud cover will be in place across the
area.

Prevailing VFR conditions are expected on both Friday and Saturday,
although a passing shower could briefly drop conditions to sub-VFR
either day. Winds will be out of the northwest on Friday, and then
out of the west on Saturday.

&&

.MARINE...
No marine hazards are expected outside of diurnally driven
scattered showers and thunderstorms today. SMWs may be needed as
thunderstorms approach the waters later this afternoon and into
the evening hours. A better focus for more organized
thunderstorm activity looks to occur late tonight into Wednesday
morning. Winds will remain light while turning westerly on
Wednesday, and may potentially near SCA levels across northern
portions of the Bay.

SCA conditions are possible over most of the local waters Thursday
and Friday due to southerly channeling. Strong to severe
thunderstorms are possible Thursday, with Special Marine Warnings
likely needed as storms move through in the afternoon and early
evening hours.

Small Craft Advisories are likely needed on Friday into Friday night
as a strong cold front tracks across the waterways. Northwesterly
winds behind this front will see a brief shift to southerlies on
Saturday. However, another frontal system approaches late Saturday
into Sunday. This is expected to bring another shot for Small Craft
Advisories during the second half of the weekend.

&&

.TIDES/COASTAL FLOODING...
Tidal anomalies have decreased markedly from yesterday afternoon
into the overnight hours. As a result, no flooding is expected with
the next two tide cycles. Some of the more sensitive sites will
reach Action stage during that time. Winds turn southerly tonight,
which should allow anomalies to increase again. Some of the more
sensitive sites may approach Minor flood stage with the tide cycle
tomorrow morning. Thereafter, winds turn westerly for both Wednesday
and Thursday, which should allow anomalies to decrease once
again.ld be at sensitive locations in Annapolis and Straits
Point that could reach minor flood during high tide early
Tuesday morning, and again early Wednesday morning. Southerly
winds increase Wednesday and Thursday, which could result in
additional coastal flooding as tide levels rise again.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.

&&

$$

SYNOPSIS...EST
NEAR TERM...EST/99
SHORT TERM...EST
LONG TERM...KJP/99
AVIATION...KJP/ADM/99
MARINE...BRO/EST/99
TIDES/COASTAL FLOODING...