045
FXUS61 KLWX 261856
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
256 PM EDT Thu Jun 26 2025

.SYNOPSIS...
A ridge of high pressure overhead will maintain hot conditions
through this evening. Daily chances for showers and storms will
increase through the end of the week. A weak frontal boundary
will slowly drift southward in time before stalling nearby
through Friday. This system gradually lifts northward away from
the area this weekend. A stronger cold front may cross the
region by early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Abundant sunshine and substantial moisture recovery has really
increased the instability across the region this afternoon. A
cooler start to the day, and a slightly stronger cap than
yesterday, held convection at bay for a few extra hours this
afternoon compared to yesterday. But now, amidst a very unstable
air mass characterized by around 4000 SBCAPE, CI has begun west
of I-81, and perhaps even starting to see some storms along the
Bay/River breezes further east. Current mesoanalysis shows very
little in the way of wind shear, so storms today will have very
similar characteristics to yesterday and remain shorter-lived
and disorganized. However, the coverage is going to be more,
especially as we head later into the evening. Storms currently
over the Potomac Highlands will start to throw down some outflow
boundaries that will quickly move east throughout the afternoon.
more storms will likely develop east of the Blue Ridge as the
convective temperature is reached, as well as along lingering
surface boundaries from yesterday and Bay/River breezes. In
short, it is going to be a very messy convective mode today.
Concern is building for the potential for damaging wind gusts,
as DCAPE values are creeping up in excess of 1000 J/kg. A very
moist column, leading to 2"+ PWATs, paired with steep low-level
lapse rates will yield an environment favorable for wet
microbursts. A Severe Thunderstorm Watch was issued through this
evening for this threat for all areas east of the Allegheny
Front.

Additionally, as we head into this evening a slow-moving
backdoor cold front will drop south across northeast MD. As
this occurs, enhanced frontal lift coupled with perturbations in
the mid/upper atmosphere will continue to fire off additional
showers and thunderstorms into the evening. Really becoming
concerned that there may be a focused area of heavy
thunderstorms along the I-95 corridor, which could lead to some
flash flooding, especially in urban areas. A Flood Watch was
issued to depict this threat area.

Most high-resolution models depict activity waning after
midnight so any severe/flood threat should wane at that point.

Besides the convective threats, continued above average
temperatures and high humidity levels will carry heat indices
into the 102 to 107 degree range. Furthermore, Heat Advisories
extend over a bulk of the area outside the mountains from 11 AM
until 7 PM this evening. Continue to find ways to stay cool in
the heat by taking plenty of breaks from the outdoors, staying
hydrated, and wearing light clothing. Heading into the overnight
hours, the influence of rain-cooled air should help carry lows
into the upper 60s to low 70s (low/mid 60s in the mountains).

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
While the placement of the frontal zone is uncertain and likely
re-positioned by convective-scale processes, this system should
be in the vicinity of the Mid-Atlantic region on Friday. Not
only will this carry an additional risk for showers and
thunderstorms, but also comes with a challenging temperature
forecast. For those in the cool sector to the north, highs in
the mid/upper 70s are likely. Off to the south and perhaps even
west of the Blue Ridge, the warm/moist sector will support
temperatures well into the 80s to near 90 degrees. The current
forecast calls for this separation of air masses to be between
I-70 and I-66.

There should be a particular focus for convection in the
vicinity of this frontal zone where lift will be augmented.
Along and south of this front will yield a severe weather
component to the storms where instability is maximized.
Additionally, well above average columnal moisture profiles
favor further instances of flooding potential. Right now, there
is the potential for this to occur across the Potomac Highlands,
per the 12z HREF. Considerations for a Flood Watch may be needed
during the overnight forecast, but didn`t want to draw attention
away from today`s threats for now. Depending on how quickly
instability is exhausted, some of the convection could fester
into the overnight hours on Friday.

With mid/upper height changes being somewhat neutral, it
remains to be seen how much northward progress this boundary
makes on Saturday. This system could easily linger right near
the Mason-Dixon Line which would maintain a more unsettled
pattern during the first half of the weekend. The expectation is
for this boundary to drift northward in time on Saturday which
will help usher highs back into the upper 80s to low 90s.
Further, convection would be driven more heavily by instability
versus along any particular frontal boundaries. But as
mentioned, there is plenty of uncertainty in how this all plays
out. Will see Saturday night`s lows be a tad milder than
previous nights with readings in the upper 60s to mid 70s.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Upper troughiness will maintain/support a surface trof across the
area while Bermuda high keeps a continued very warm and moist air
mass supporting daily chances of showers and thunderstorms Sun
into Monday. A stronger trough is fcst to amplify across the
Great Lks and Mid-Atlantic Tue pushing a stronger cold front
through the area Tue afternoon. Timing of the frontal passage
has slowed down some since yesterday supporting a greater risk
of severe thunderstorms Tue afternoon. A drier air mass will
follow behind the front for the middle part of next week and
Fourth of July.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
With convection in the forecast through the remainder of the
work week and into the first half of the weekend, periods of
restrictions are looking likely at times. Otherwise, VFR
conditions should be commonplace outside of these convective
episodes.

For this afternoon/evening, remain confident enough in thunderstorm
development to have a 3 to 4 hour period of TSRA restrictions
roughly between 20-00Z. As some of this may linger after dark,
have maintained the PROB30 groups into subsequent hours as
inherited by previous shifts. Added a TEMPO group in where we
think the best chance for stronger storms will be, with winds
gusting to 40 knots. As storms develop and approach the airport,
that number could be higher or lower, depending on placement of
storms. This is a favorable pattern for wet microbursts, to
strongest winds will be very localized in nature.

As a frontal zone drifts southward across the area, winds turn
more easterly in nature on Friday. Eventually this boundary does
return northward as a warm front which would bring a return to
south-southwesterlies at some point on Saturday. And as
mentioned, restrictions are possible given a decent chance for
thunderstorms each afternoon/evening.

VFR conditions at all terminals Sunday through Monday night. At
times of convection, we could see brief MVFR visibility and/or
ceilings. Winds will be light and variable, except higher gusts
in strong thunderstorms.

&&

.MARINE...
While gradients remain weak enough to keep the waterways free of
Small Craft Advisories, the threat of convection will make for
hazardous boating conditions at times through at least Saturday.
It is difficult to say which day will be the most active in
terms of thunderstorm development, but the degree of continued
heat and humidity should maintain a daily 30-60 percent chance
of storms each afternoon/evening. As usual, frequent lightning
is possible in any such storm, with the stronger cells likely
requiring Special Marine Warnings.

No marine hazards Sunday through Monday night. If thunderstorms
move out over the waters, then Special Marine Warnings may be
warranted. Winds light and variable through the period, except
higher gusts in strong thunderstorms.

&&

.TIDES/COASTAL FLOODING...
Tidal anomalies will remain slightly elevated through the next
several high tide cycles. This will keep water levels slightly
elevated for the more sensitive tidal sites. At this point, only
Annapolis is slated to reach Action stage during the next
couple of astronomical high tides.

&&

.CLIMATE...
Here are some daily high temperature records on June 26, 2025:

A `+` sign indicates multiple years currently hold that record.

                 ***THURSDAY, JUNE 26TH, 2025***
LOCATION                   RECORD HIGH (YEAR)  RECORD WARM LOW (YEAR)
Washington-National (DCA)     101F (1952)          77F (1952)+
Washington-Dulles (IAD)        99F (2024)          72F (2023)+
Baltimore (BWI)                99F (2024)+         80F (1952)
Baltimore Inner Harbor (DMH)  104F (1998)          83F (1952)
Martinsburg (MRB)             102F (1943)          75F (1949)
Charlottesville (CHO)          99F (1998)          78F (1952)
Annapolis (NAK)                98F (1998)+         81F (1952)
Hagerstown (HGR)               98F (1954)+         75F (1952)

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Heat Advisory until 7 PM EDT this evening for DCZ001.
     Flood Watch until midnight EDT tonight for DCZ001.
MD...Heat Advisory until 7 PM EDT this evening for MDZ003>006-008-
     011-013-014-016>018-502>508.
     Flood Watch until midnight EDT tonight for MDZ004>006-008-011-
     013-014-016-503>508.
VA...Heat Advisory until 7 PM EDT this evening for VAZ026>031-
     036>040-050-051-053>057-501-502-505-506-526-527.
     Flood Watch until midnight EDT tonight for VAZ053>057-506-526-
     527.
WV...Heat Advisory until 7 PM EDT this evening for WVZ050>053-055-
     502-504.
MARINE...Heat Advisory until 7 PM EDT this evening for ANZ530.
     Flood Watch until midnight EDT tonight for ANZ530.

&&

$$

SYNOPSIS...BRO
NEAR TERM...CJL
SHORT TERM...BRO/CJL
LONG TERM...LFR
AVIATION...LFR/BRO/CJL
MARINE...LFR/BRO/CJL
TIDES/COASTAL FLOODING...LWX
CLIMATE...LWX