349
FXUS61 KLWX 271828
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
228 PM EDT Thu Jun 27 2024

.SYNOPSIS...
High pressure will build in from the west today in the wake of a
cold front. This will push offshore late Friday into Saturday
morning, pushing a warm front through the region on Saturday
which will bring showers and thunderstorms back to the region.
A cold front will then push through on Sunday, bringing yet
another chance for afternoon showers and thunderstorms. High
pressure then returns for the early portion of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Moisture aloft has lead to the development of a very prominent
cu deck across much of the area, but high pressure moving in
from the west should keep us dry through the evening hours.

For tonight, in the wake of the aforementioned cold front,
temperatures will drop into the mid 60s for most (low 70s near
the water). Dew points will also drop well into the 50s, which
will make it feel much less muggy overnight.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
For Friday, high pressure will move overhead, leading to dry
conditions overall. The only thing really to talk about tomorrow
will be potential for some clouds, albeit with no chance for
rain. The 850 hPa high will be a bit further south, thus
turning flow out of the south in the low-mid levels, which
should usher in plenty of moisture for a solid cu deck. Again,
it will be far too stable for any precipitation to develop, but
just something to note.

Friday night that area of high pressure will move offshore and
low pressure will begin to track across the Great Lakes. The
warm front associated with this low will begin to lift through
the region, turning surface flow out of the ESE. This will
usher in a much warmer and very humid air mass into the region
for the weekend. Overnight lows jump into the upper 60s to low
70s, with dew points nearly mirroring that. With onshore flow,
would expect some low clouds to develop adjacent to the Blue
Ridge, which could even be in the form of fog, though surface
flow may be a bit too quick for that. There will also be some
showers around by Saturday morning.

Saturday is where things really start to get interesting. That
warm front that was mentioned earlier will lift north through
the region throughout the morning into the afternoon hours.
Looking aloft, the upper trough is centered well to our north,
but there does appear to be a piece of shortwave energy that
will slide by near/north of our area. This will be where things
get tricky as that interacts with the warm front itself.

Getting back to our area, how does this impact us locally? Well,
with the warm front potentially still over portions of our
region, forecast soundings are a bit concerning in the low-
levels right along that with some decent low-level shear showing
up. This will be paired with highs in the low 90s and dew points
in the low to mid 70s, which should yield plenty of instability
to pop off some thunderstorms. Model guidance has come into much
better agreement with a consensus of anywhere between 1000-2000
J/kg of CAPE in place, which tracks given the temp/dew point
combo mentioned above. The Storm Prediction Center already has
most of our area in a marginal risk for severe weather, with a
slight risk just to our northwest. Thinking that the highest
threat is going to be exactly where that piece of energy ends of
going and/or if there are any other mesoscale features upstream
to monitor, which is pretty common in June. Storms that develop
Saturday afternoon will have a lot going for them, especially
near the warm front. Damaging wind gusts and a tornado or two
would be my primary concerns Saturday. Looking at some of the
machine learning guidance we have at our disposal these days
confirms that thought as well, with the CSU Machine Learning
tornado probs in the 2-5% range Saturday. The highest threat is
concentrated along the MD/PA border northward, and that is
reflected in our POP forecast updated this afternoon.

A lot can change with this forecast, so keep that in mind.
Mesoscale features are extremely difficult to pin down a few
days out, but just wanted to highlight that the parameter space
is concerning. Please visit weather.gov/lwx for our latest
forecast, and spc.noaa.gov for the latest severe weather
outlooks.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
A cold front will be approaching the area on Sunday,
allowing for increasing chances for showers and thunderstorms.
Additionally, temperatures will be elevated into the low to mid 90s
with increased dewpoints bringing heat indices into the upper 90s to
even some areas reaching triple digits. Heat Advisories may be
needed in some areas. Convective parameters appear favorable for
some damaging winds along and just ahead of the frontal passage on
Sunday.

Precipitation chances slowly wane heading into the workweek, with a
strong area of high pressure centered over the Great Lakes
influencing the area locally here in the Mid-Atlantic. Post-frontal
northwest flow on Monday will allow temperatures to drop down into
the upper 70s to low 80s for the lower elevations with even upper
60s in the mountains. A gradual warmup will ensure Tuesday into
Wednesday with mostly dry conditions expected until Wednesday when a
disturbance begins to approach the eastern seaboard with an
associated low pressure centered over some of the eastern Canadian
provinces. Highs on Wednesday climb back into the low 90s for most
areas east of the Allegheny Front.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
Northwest winds gusting up to 15 knots expected for the
remainder of the afternoon under VFR conditions.

Mostly dry conditions follow and continue into Friday as high
pressure passes to the north. Winds early in the day will be
5-10 knots out of the NE before slowly turning out of the SE by
the afternoon.

Onshore flow Friday night into Saturday morning could bring some
lowered CIGs along/east of the Blue Ridge, which could
particularly impact CHO. Lowered VSBY is possible, but winds are
expected to be prominent enough to keep fog threat pretty low.

Sub-VFR conditions are likely Saturday with any showers and
thunderstorms that move across the terminals. A warm front lifts
through the area in the morning/afternoon with some shower
activity expected, and more is expected in the afternoon and
evening with the potential for strong to severe storms.

Sub-VFR conditions will be possible Sunday ahead of a cold front
passage. Some of these storms may be strong to severe throughout the
afternoon and evening hours. Conditions improve late Sunday night
into Monday with VFR conditions returning for the first half of the
workweek.

&&

.MARINE...
Sub-SCA winds expected through this evening with no marine
hazards expected at this time.

As flow turns out of the NE when high pressure moves east
tonight, there may be a brief pressure surge over the waters
that could near SCA criteria. Confidence wasn`t high enough for
an SCA, and honestly it could be very brief over any one given
point (<2 hours). Think that any surge could likely be handled
with a Marine Weather Statement.

As winds increase out of the SW, SCAs may be needed Friday evening
and again with strengthening southerly flow and a passing warm front
on Saturday. Additionally, any storms that develop Saturday
could produce damaging wind gusts and need SMWs. Additionally,
there is a non-zero threat for waterspouts as well. Both of
these threats seem greatest in northern portions of the waters
at this time.

Showers and thunderstorms will likely impact the waters on Sunday
along and ahead of a cold front passage. SMWs may be needed during
the afternoon and evening on Sunday. SCAs may also be needed briefly
after the cold front heading into early Monday with northerly
channeling continuing.

&&

.TIDES/COASTAL FLOODING...
Tidal anomalies will remain low over the next day or so as winds
turn briefly out of the NW, then NE tonight.

However, winds will turn out of the SE, then S Friday into the
weekend ahead of a strong cold front pushing through Sunday.
This will likely bring anomalies back up, with minor flooding
possible on the Sunday high tide cycles.

The cold front will then push through Sunday and turn winds out
of the NW, thus pushing water back towards the south and
lowering anomalies once again.

&&

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

&&

$$

SYNOPSIS...EST
NEAR TERM...CJL
SHORT TERM...CJL
LONG TERM...ADM
AVIATION...CJL/ADM
MARINE...CJL/ADM
TIDES/COASTAL FLOODING...CJL