103
FXUS61 KLWX 070759
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
359 AM EDT Tue Jul 7 2026

.WHAT HAS CHANGED...
After extending Flood Watches until 2 AM for areas along/east of
the Blue Ridge, these were allowed to expire on time. Additional
Flood Watches are likely need across portions of the region
today. Otherwise, the unsettled pattern appears on track
although a brief mid-week lull is possible as the frontal zone
sags off to the south.

&&

.KEY MESSAGES...
- 1) Another round of heavy showers and thunderstorms are
  expected through this evening.

- 2) Daily shower and thunderstorm chances continue as a cold
  front brings precipitation and the return of seasonable
  temperatures.

&&

.DISCUSSION...
KEY MESSAGE 1...Another round of heavy showers and thunderstorms
are expected this evening.

Active overnight convection has generally thrived across
portions of the area. However, over the past couple of hours,
much of this has finally eroded as convective inhibition has
increased in time. Where residual elevated instability exists,
isolated showers and thunderstorms continue to form in the wee
hours of the night. Unless this activity can lock onto an old
outflow boundary or terrain, any new flash flood threat is
unlikely. A few Flash Flood and/or Flood Warnings remain in
effect across Prince William, Loudoun, and Fauquier counties.
Until river/stream gauges drop below minor and rainwater begins
to recede, plan on maintaining such warnings until daybreak.
Continue to adhere to any road closures set by law enforcement.

Within the convectively overturned air mass, conditions are
fairly seasonable this morning with temperatures and dew points
in the upper 60s to mid 70s. The stable boundary layer has begun
to trap low level moisture in the atmosphere. Consequently, a
number of locations are seeing the development of low stratus
clouds, generally with bases around 500 to 1,000 feet. This is
occurring amidst a light north to northeasterly wind as a
frontal zone lies just south of U.S. 50. Where this boundary
sets up later today will play a key role in where an additional
flash flood risk occurs.

Underneath mainly overcast skies today, forecast highs will
range from the upper 70s to mid 80s, locally near 90 degrees
closer to the I-64 corridor. The expectation is for this front
to meander north to south, generally being repositioned by
convective-scale processes and where cloud breaks occur. A
tropical air mass remains in place with precipitable water
values staying in the 2 to 2.25 inch range. The tropospheric
flow stays on the weaker side which favors slow and rather
chaotic cell motions. 00Z high-resolution models shift the focus
for more concentrated convection to along/west of U.S. 15. This
generally marks where the Weather Prediction Center has a
Slight Risk for flash flooding today. With heavy rainfall
characterized by intense rainfall rates and a threat for
repeat/training convection, Flash Flood Watches are likely
needed again. The most vulnerable spots would be areas hit by
recent heavy rainfall over the past couple of days. River and
stream levels began low due to ongoing drought conditions.
However, these have risen recently which makes them more
vulnerable to future flooding.

On the severe weather side of the equation, the Storm Prediction
Center features a Marginal Risk across the Shenandoah Valley
down toward central Virginia between I-64 and I-95. While
instabilty and vertical shear are not terribly impressive,
moisture loaded downdrafts will be capable of producing isolated
pockets of wind damage. Once the sun goes down, any severe
threat should wane with the loss of diabatic heating.

By mid-week, the parent frontal zone is expected to reach the
Carolinas while stretching back up into the central
Appalachians. As an upstream shortwave trough continues to shear
on its eastward approach, the residual energetics from this
feature will keep convection in the forecast. Any severe threat
appears minimal, but some non-zero flood threat persists given
recent bouts of heavy rainfall. Owing to mainly east to
northeasterly surface winds, Wednesday will yield below average
temperatures with highs in the upper 70s to mid 80s, with mid
60s to mid 70s for the mountains.


KEY MESSAGE 2...Daily shower and thunderstorm chances continue as a
cold front brings precipitation and the return of seasonable
temperatures.

An approaching cold front brings showers and thunderstorms to the
forecast area Thursday into Friday. Hot and humid conditions
will lead to moderate instability. This along with modest shear
may result in at least isolated severe potential. With plenty
of moisture in the atmosphere, heavy rainfall will also be
possible. The cold front slowly pushes across the forecast area
Friday night and into Saturday with seasonable temperatures
expected in its wake. High temperatures for the weekend will be
in the upper 70s to 80s with overnight low temperates dropping
into the 60s to low 70s.

Heading into early next week, there are signs at a potentially
amplified pattern which could bring a return to storm chances.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
Unlike last night where low ceilings never really materialized,
most TAF sites have dropped to IFR conditions. Current ceilings
range from 600 to 800 feet as low-level moisture has become
trapped in the stable boundary layer. Wind fields again remain
on the lighter side but with a general northeasterly component.
Through the day, expect a gradual improvement to MVFR by around
8-9 AM before reaching VFR just before the noon hour. Have again
kept a 6-hour PROB30 group which spans 18Z-00Z this afternoon
and evening. This would mark the greatest opportunity for
restrictions, accompanied by frequent lightning and
gusty/erratic winds. KMRB and KCHO have the highest probability
of storms today, while slowly decreasing off to the east.
Another round of low ceilings are possible tonight into
Wednesday morning. Winds turn more easterly through the day with
some diurnal showers and thunderstorms possible. Any stronger
storm could yield brief sub-VFR conditions.

Southwest winds on Thursday blow 5 to 10 knots across the terminals.
Showers and thunderstorms may result in flight restrictions with
reduced ceilings and visibilities. Winds shift to westerly on
Friday, gusting up to 15 knots in the afternoon. Showers and
thunderstorms continue to be possible Friday afternoon. Winds shift
to northwest in the wake of a frontal passage Saturday, gusting
around 15 knots in the afternoon.

&&

.MARINE...
Sub-advisory caliber winds are expected across the waters given
weaker gradients. Any hazardous conditions are likely going to
be tied to convection, lightning, and any accompanying gust
fronts/outflows. Additional thunderstorm chances are maintained
in the afternoon/evening forecast. Special Marine Warnings will
be required for any stronger convection. The coverage of
stronger storms likely decreases into Wednesday. Through mid-
week, expect mainly east to northeasterly winds with gusts up to
around 10 knots.

Daily chances for showers and thunderstorms lead to a risk for
SMWs Thursday and Friday. Southwest winds on Thursday shift to
westerly on Friday, remaining below SCA criteria each day. On
Saturday, winds shift to northwesterly in the wake of a frontal
passage.

&&

.TIDES/COASTAL FLOODING...
Light onshore (east to northeast flow) the next couple days
followed by southerly flow will cause rising tides later this
week. This may result in near minor flooding of vulnerable
shoreline the second half of this week.

&&

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

&&

$$

DISCUSSION...AVS/BRO
AVIATION...AVS/BRO
MARINE...AVS/BRO
TIDES/COASTAL FLOODING...LWX

NWS LWX Office Area Forecast Discussion