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039
FXUS61 KLWX 281429
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1029 AM EDT Sat Jun 28 2025

.SYNOPSIS...
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Humid conditions continue today with warmer temperatures as a warm
front lifts north of the area. Scattered showers and thunderstorms
will accompany the front this afternoon and evening especially along
and east of Interstate 81. Additional showers and thunderstorms are
likely Sunday as a weakening cold front drops southward into the
region. Shower and thunderstorm chances continue Monday and Tuesday
as a stronger cold front moves into the region. Less humidity
and drier conditions are expected late next week.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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Continuing to see a slow erosion of the CAD wedge this morning from
northern VA north and east into central/northeast MD. Low clouds and
patchy drizzle/fog continue to persists in these areas with mostly
sunny to partly cloudy skies south and west where the wedge has
eroded. In between these aforementioned areas lies a warm frontal
boundary which is currently draped from west-central PA south toward
Richmond, VA. This front will continue to lift northward later this
morning into midday allowing for warmer temperatures and more
humidity to move back into the region. Highs today will surge back
into the upper 80s and lower 90s east of the Alleghenies. Mountain
locations will be a touch cooler in the low 80s. Heat index values
will hover close to 100 degrees east of US-15 with mid 90s further
west. This will put us just shy of Heat Advisory criteria with
fairly moist airmass (i.e dewpoints in the low to mid 70s) and
limited dry air in the mid levels mixing down.

Synoptically, high pressure will continue to push further out into
the Atlantic allowing the warm front to lift north and the CAD
wedge to erode heading into mid-afternoon. Meanwhile, a surface
trough will reside in the vicinity of the I-81 corridor as
850-925mb westerly downsloping flow ensues in the lee of
Appalachians/Alleghenies. This trough will become the main
focal point for convection this afternoon and evening (between
19-00Z/3- 8pm). Convection appears to be loosely organized (i.e
pulse or multicellular clusters) feeding off of MUCAPE values of
2500-3500 j/kg and 0-6 km shear values of less than 25 kts. 0-1
SRH values are expected to hover between 15-30 m2/s2 with DCAPE
hovering between 600-900 j/kg. This should allow for some
movement with the storms today although locally damaging winds
and isolated instances of flash flooding appear to be the
primary concerns. PWATS will continue to remain high hovering
between 1.7-2.3 inches yielding efficient rain rates of
1-2"/hr.

Showers and thunderstorms should initialize around I-81 between 2-
4pm before slowly drifting east toward the metros between 4-8pm
tonight. An isolated shower or storm could pop further east
along the river/bay breeze, but confidence in the evolution of
this remains low at this time. Storms gradually diminish through
the late evening hours (01-03z/9-11pm) with loss of daytime
heating, with mainly dry conditions through the overnight hours.
Some patchy fog can`t be ruled out late tonight, especially in
locations that receive thunderstorms during the daylight hours
today. Overnight low temperatures will be in the upper 60s to
the west of the Blue Ridge, and lower to middle 70s further
east.
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&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
A decaying cold front will drop southward into the area during
the day tomorrow. This boundary will have little impact on
temperatures, as most locations should still climb into the
upper 80s and lower 90s. However, slightly drier air will start
to filter in from the north, with precipitable water values
dropping through the afternoon to the north of I-66/US-50.
Further south, deeper moisture will remain in place. While an
afternoon thunderstorm can`t be completely ruled out anywhere,
the primary focus for storms should be within the deeper
moisture to the south of I-66/US-50. SPC currently has much of
the forecast area outlooked in a Marginal Risk for severe
thunderstorms, driven by the potential for localized high winds
caused by wet microbursts.

We`ll remain within a hot and humid airmass on Monday, with
temperatures once again climbing into the upper 80s and lower
90s. Afternoon showers and thunderstorms will once again
accompany the heat and humidity. Coverage of storms may be
a bit higher compared to Sunday, especially across the northern
half of the forecast area.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Monday and Tuesday should be the last few days of afternoon and
evening convection as a front to the northwest on Monday moves
through the region on Tuesday. Showers and thunderstorms, some
strong to possibly severe, will accompany the front and also
develop well ahead of the front on Monday with a prefrontal
trough. Highs in the upper 80s to lower 90s both days. Height rises
and building high pressure will result in seasonable temperatures
and dry and tranquil conditions, finally, Wednesday and
Thursday.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
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IFR to LIFR conditions are ongoing at the terminals in
association with low ceilings and drizzle. Rapid improvement is
expected today between 15-17z/11am-1pm, with conditions likely
becoming MVFR by midday, and VFR by afternoon. Thereafter,
prevailing VFR conditions are expected through Monday. Temporary
restrictions due to thunderstorms may be possible each
afternoon and evening. Today, IAD, MRB, and CHO have the
greatest chance of seeing impacts from storms, but a brief storm
can`t be ruled out anywhere. Winds will be out of the south
today, northwest Sunday, and then south again on Monday.

VFR conditions at all terminals Monday through Tuesday night with
exception to brief MVFR conditions in strong thunderstorms each
afternoon and evening.
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&&

.MARINE...
Sub-SCA level winds are expected over the waters through Monday
morning. Winds will generally be southerly today, light and
variable on Sunday, and southerly again on Monday. Winds may
reach low-end SCA levels within southerly flow by later Monday
afternoon into Monday night. SMWs as a result of thunderstorm
winds may be possible each afternoon or evening through Monday.

No marine hazards Monday through Tuesday night with exception
to any strong thunderstorms that develop near or over the waters
Monday afternoon and evening and again Tuesday afternoon and
evening.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
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DC...None.
MD...Coastal Flood Advisory until 11 AM EDT this morning for MDZ014.
VA...None.
WV...None.
MARINE...None.
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&&

$$

SYNOPSIS...EST
NEAR TERM...KJP/EST
SHORT TERM...KJP
LONG TERM...KLW
AVIATION...KLW/KJP/EST
MARINE...KLW/KJP