064
FXUS61 KLWX 080117
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
917 PM EDT Sun Jul 7 2024

.SYNOPSIS...
A front stalls south of the area today, with dry and less humid
conditions in the wake of the front. Heat, humidity, and daily
thunderstorm chances return for much of the upcoming week as the
front lifts north across the area Monday and lingers into
Tuesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Isolated showers over the eastern panhandle of West Virginia
have dissipated with no precipitation expected for the rest of
the night. No changes to the forecast package with the
exception of patchy fog being added. Low temperatures will be
in the upper 60s to 70s for most with those in the metro areas
are expected to stay in the low 80s.

Previous Discussion Follows:
Today will be the quietest in what feels like a while, with
only isolated PoPs restricted to southern Maryland and
neighboring waters. Some weak showers have developed over east
central Virginia (south of our area) and moved over the
Chesapeake Bay. Any showers that do move over the waters and
southern Maryland will be similar to these.

Some CAMs have been suggesting some convection over the terrain
in our far southwestern zones, but there isn`t any real
agreement among the hi-res models for this development. CAMs
have also not had a good handle on the weak shower activity
along the frontal boundary to our southeast, so taking their
guidance with a grain of salt. Currently do not have PoPs in our
southwest, but will continue to monitor later this afternoon
and see what (if anything) initiates upstream.

Compared to recent days, today feels less hot and humid with
highs in the 90s and dewpoints in the 60s, apparent temperatures
running 3-4 degrees warmer in general. Winds today are fairly
light out of the northwest, and likely goes calm in many
locations tonight as brief high pressure builds in from the
northwest. Lows tonight will be a bit cooler in the low 70s for
most of the area, and upper 60s in the mountains. Metros and
areas along the water will only get down to the upper 70s or 80.
The lower humidity will make the overnight feel less muggy than
previous nights however.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
On Monday, the boundary stalled currently stalled to our
southeast is expected to lift back into the region as a warm
front. With moisture returning to the area on southeasterly
flow, and southwesterly flow aloft, isolated to scattered
showers and thunderstorms are expected during the afternoon and
evening. The focus of shower activity will depend on the
location of the front, but for now best chances appear to be
over the Shenandoah Valley and portions of central Virginia.
High temperatures rise into the mid to upper 90s for much of the
area, and heat indices to over 100 east of the Blue Ridge.

The large trough over the central CONUS is expected to advance
eastward on Tuesday, possibly absorbing remnants of Beryl. A
frontal boundary is still expected to be stalled over our area.
While southerly flow will continue to bring moisture into the
region and enable scattered showers and thunderstorms Tuesday,
flow aloft looks to become more westerly, which could suppress
shower activity in comparison to Monday. Temperatures Tuesday
will be similar to Monday, but the increasing humidity likely
results in slightly higher heat indices, approaching or
exceeding 100 degrees for much of the area, and 105 east of the
Blue Ridge. We will continue to monitor the heat risk. As we get
towards midweek, the forecast for our area becomes more
dependent on Beryl`s evolution, so confidence for Tuesday`s
forecast is low.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
A frontal zone is expected to continue drifting northward away from
the area on Wednesday. This places the Mid-Atlantic region squarely
in the warm/moist sector which carries dew points back into the mid
70s. In addition to the increasing humidity levels, high
temperatures are expected to rise into the mid 90s which would
contribute to 100 to 105 degree heat index values. With
southwesterly flow aloft ushering in a series of disturbances
through the region, an increasingly unsettled pattern looms ahead.
One wild card in play is the remnants of Beryl which are expected to
usher in tropical moisture across the Ohio Valley into the Mid-
Atlantic. Where the best energetics and moisture transport reside
will provide an additional emphasis for heavier rainfall. This would
ultimately dictate where any flash flood threat will set up.

On Thursday, the forecast has trended warmer with an upstream cold
front not slated to reach the area until at least midday. The
current forecast calls for high temperatures in the low 90s with
heat indices nearing the century mark. With the remnants of Beryl
still in the vicinity, showers and thunderstorms are likely to
persist into Thursday. A residual flooding threat cannot be ruled
out given the multi-day nature of this system. With subtropical
ridging over the western Atlantic holding strong, this frontal
passage will be slow and perhaps lead to another stalled boundary.
The latest forecast shows this system lingering over the general
area through early in the weekend before shearing out. High
temperatures stay near average through Saturday before warming back
up into the low/mid 90s by Sunday. Continued opportunities for
showers and thunderstorms also loom given the stalled front
nearby.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
VFR conditions are expected today, and most of time for Monday
and Tuesday. The boundary to our southeast returns as a warm
front on Monday, bringing showers and thunderstorms in the
afternoon. CHO and MRB appear most likely to see precipitation
at this time, but will depend on where the boundary sets up on
Monday. Showers and thunderstorms are also possible Tuesday, but
confidence on where is currently low. The forecast for Tuesday
and onwards is more dependent on Beryl/Beryl`s remnants, so has
been less consistent. Currently appears the westerly flow aloft
on Tuesday will suppress shower activity in comparison to
Monday.

With the remnants of Beryl passing nearby on Wednesday and Thursday,
there should be some periods of restrictions at the area terminals.
This would include a risk of thunderstorms given the degree of
instability in the atmosphere. An unsettled weather pattern
continues into Friday with additional restrictions possible.
Southerly winds are expected through Thursday with afternoon gusts
up to 15 knots. Behind a weak front, winds turn more variable on
Friday.

&&

.MARINE...
Light north/northeast flow today becomes east tonight and then
southerly on Monday. Winds are expected to gradually increase
out of the south through Tuesday. Sub-SCA winds are expected on
Monday, but winds over the waters could approach SCA criteria by
Tuesday afternoon, especially with any southerly channeling.
Additionally, a warm front lifts back into the region Monday and
likely lingers on Tuesday. Any associated showers and
thunderstorms could bring stronger gusts to the waters. Most
storms are expected to be west of the waters on Monday, but
Tuesday is less certain.

There will be some opportunities for Small Craft Advisories during
portions of Wednesday and Thursday owing to southerly channeling
effects. Additionally, convective chances also increase as a front
and the remnants of Beryl approach from the west. Special Marine
Warnings may be needed for any of the stronger thunderstorms. This
boundary stalls nearby on Friday leading to continued opportunities
for showers and thunderstorms. Depending on where the boundary sets
up, southerly channeling may become a factor again on Friday.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Heat Advisory from noon to 8 PM EDT Monday for DCZ001.
MD...Heat Advisory from noon to 8 PM EDT Monday for MDZ004>006-008-
     011-013-014-016>018-503>508.
VA...Heat Advisory from noon to 8 PM EDT Monday for VAZ039-040-050-
     051-053>057-501-502-505-506-526-527.
WV...None.
MARINE...Heat Advisory from noon to 8 PM EDT Monday for ANZ530.

&&

$$

SYNOPSIS...CAS/KRR
NEAR TERM...AVS/CAS
SHORT TERM...CAS
LONG TERM...BRO
AVIATION...BRO/CAS
MARINE...BRO/CAS