Flash Flood Warning 36, NWS Baltimore/Washington

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1035 AM EDT Mon Aug 10 2026

.WHAT HAS CHANGED...
Cluster of storms that has been moving across southern
Pennsylvania is brushing north-central and northeast MD.
Monitoring thunderstorms/upper air disturbances in the Ohio
Valley as to what impact they may have on local storm chances
this afternoon and evening.

&&

.KEY MESSAGES...
- 1) An active start to the new workweek with multiple chances for
severe weather. Hot temperatures and high humidity continue.

- 2) Turning cooler toward the end of the week, although showers
  and thunderstorms remain possible at times.

&&

.DISCUSSION...
KEY MESSAGE 1... An active start to the new workweek with multiple
chances for severe weather. Hot temperatures and high humidity
continue.

Shaping up to be a fairly active weather pattern today through
Wednesday as multiple pieces of shortwave energy traverse the
region. Other than a few pulse updrafts, thunderstorms moving
into northeast Maryland have been on a weakening trend as
outflow outpaces the convection, so am not expecting any severe
weather with this round. Thunderstorms are now filling in across
eastern Ohio on the southern flank of a long standing MCS. More
thunderstorms are in western Ohio diving southward toward higher
instability. While current trajectories of the storms may only
clip northern portions of the forecast area, further evolution
is possible. Some home-grown storms aren't out of the question
either. Beyond this round of forcing, uncertainty increases with
some models showing additional thunderstorms or their remnants
from upstream reaching the area overnight. If this occurs, it
could have some effects on modulating the corridor of highest
severe risk on Tuesday.

What we do know is that whatever occurs the ingredients will be
there for severe weather development. This is due in part to
strong daytime heating with highs in the upper 80s and mid 90s.
Dewpoints will remain in the upper 60s to mid 70s yielding heat
index values around 100 degrees east of the Blue Ridge. The heat
combined with a shortwave disturbance aloft should be the
kicker for at least a few severe thunderstorms to develop.
SPC has expanded the Slight Risk a bit to the south, with a
Marginal Risk remaining across the rest of the region. Damaging
winds will be the primary threat with storms along with
isolated large hail. Machine guidance continues to advertise a
high ceiling on the severe threat with WxNext2 probabilities of
45-70 percent and CSU probabilities of 15 to 30 percent across
the area this afternoon and evening.

Additional shortwave disturbances look to pass through Tuesday into
Wednesday. Mid-level flow will increase during this time along with
stronger height falls yielding more widespread convective chances.
With that said, uncertainty remains in regards to timing, coverage,
and location of the storms during the period. This is largely due in
part to the evolution of any MCSs ejecting out of the Ohio River
Valley/Great Lakes region along with the remnant outflows left
behind. Right now, Tuesday appears to be the day with the greatest
coverage of showers and thunderstorms along with an increased risk
for severe weather. SPC maintains a Slight Risk (Level 2 out of 5)
for eastern WV/far western MD and the Shenandoah Valley. A Marginal
Risk (Level 1 out 5) has been outlooked elsewhere across the region
for Tuesday into Tuesday night. Damaging winds will once again be
the main threat along with isolated large hail.

Beyond Tuesday, timing, coverage, and locations of storms remains
uncertain despite strong mid level flow and increased height falls
across the region. Shortwave disturbances will continue to pulse
through although more cloud cover may be noted which could dampen
the threat. This aligns with machine learning probabilities of
10-30 percent probs across the area. These probabilities taper
even more late week as the front finally drops into the region.
Once again damaging winds will be the main threat with storms.

The risk for isolated flash flooding could occur anywhere on any
day if a merging or backbuilding storm were to occur over a
susceptible area. Accumulatively, however, the risk of flooding
is greatest near and west of the Appalachians where several
rounds of heavy thunderstorms may occur over the next several
days.

KEY MESSAGE 2...Turning cooler toward the end of the week, although
showers and thunderstorms remain possible at times.

Daily storm chances look to continue through at least Friday as a
frontal system tracks toward the region. Ahead of that front will be
several fast moving shortwave disturbances which will help aid in
shower and thunderstorm development during the diurnal periods.

Th southward progress of the cold front becomes more uncertain for
the end of the week, although it likely drifts south with time
(especially Friday into Saturday). Both physics-based and AI
guidance shows lower severe weather chances Thursday with declining
instability. Showers and thunderstorms could remain possible though
with the front nearby. For Friday and Saturday in particular, there
may be a better chance of drying out as high pressure builds to the
north. This will also bring a corresponding cool down in
temperatures (potentially a bit below normal) along with lower
humidity. The front won't be too far to the south however, and will
likely attempt to lift north later this weekend or early next week
as a low pressure system moves into the Great Lakes. Thus, some low
end PoPs remain in the forecast each day through the end of the
forecast period.

Temperatures will cool from the upper 80s and low 90s Thursday into
the low to mid 80s Saturday. Overnight lows will fall back into the
low to mid 60s with 50s over the mountains.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
VFR conditions look to prevail across the terminals through Friday
given subtropical high pressure offshore and the lack of any
significant front passing through. Brief periods of sub-VFR
restrictions are likely during the afternoon and evening hours due
to thunderstorms, especially today through Wednesday. Thunderstorm
coverage lowers Thursday and Friday as a front gradually sags
through the region.

One cluster of storms is passing just north of MTN this morning.
Then attention turns to what might approach from the Ohio Valley
and/or develop off the terrain locally. Will maintain general
mid afternoon to early evening timing in the TAFs for now, with
hopefully more clarity provided by 18Z. Storm coverage remains
uncertain with gusty winds, frequent lightning, and locally
heavy rainfall as the primary concerns. Will eventually convert
to TEMPOs when confidence increases on coverage (which might be
highest at MRB/BWI/MTN this afternoon). Similar conditions are
expected Tuesday and Wednesday with restrictions possible in the
afternoon and evening due to thunderstorms.

Outside of the thunderstorms expect patchy fog between the terminals
each morning through Thursday. Winds will remain light out of the
west and southwest at less than 15 kts.

VFR conditions are expected this upcoming weekend with isolated
showers and thunderstorms returning Sunday into early next week as
the front tries to lift back into the region.

&&

.MARINE...
A brief period of southerly channeling may return to the middle and
open waters of the Chesapeake Bay this afternoon and evening with
sub-SCA level winds over most of the waters. Overall sub-SCA level
winds are expected through Wednesday. Wind speed and direction are a
bit uncertain Thursday and Friday as a cold front gradually pushes
through the area. While winds appear to be mostly sub-SCA at this
time, there could be an enhanced northwesterly surge once the front
does push through.

Outside of the background winds, expect daily shower and
thunderstorm chances each afternoon and evening through
upcoming workweek (though can't rule out storms overnight and in
the mornings as well, such as those currently moving across the
far northern Chesapeake). Special Marine Warnings may be needed
to encompass any stronger thunderstorms that may form
especially today through Thursday. Damaging wind gusts and
frequent cloud- to- ground lightning will be the main threats.

&&

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

&&

DISCUSSION...ADS/KJP/EST
AVIATION...ADS/KJP/EST
MARINE...ADS/KJP/EST

Hazardous Weather Outlook
National Weather Service Baltimore MD/Washington DC
117 PM EDT Mon Aug 10 2026

ANZ530>543-DCZ001-MDZ008-011-013-014-016>018-504-506-508-
VAZ053>057-527-111000-
Chesapeake Bay north of Pooles Island MD-
Chesapeake Bay from Pooles Island to Sandy Point MD-
Chesapeake Bay from Sandy Point to North Beach MD-
Chesapeake Bay from North Beach to Drum Point MD-
Chesapeake Bay from Drum Point MD to Smith Point VA-
Tidal Potomac from Key Bridge to Indian Head MD-
Tidal Potomac from Indian Head to Cobb Island MD-
Tidal Potomac from Cobb Island MD to Smith Point VA-
Patapsco River including Baltimore Harbor-
Chester River to Queenstown MD-Eastern Bay-
Choptank River to Cambridge MD and the Little Choptank River-
Patuxent River to Broomes Island MD-
Tangier Sound and the inland waters surrounding Bloodsworth
Island-District of Columbia-Cecil-Southern Baltimore-
Prince Georges-Anne Arundel-Charles-St. Marys-Calvert-
Central and Southeast Montgomery-Central and Southeast Howard-
Southeast Harford-Fairfax-Arlington/Falls Church/Alexandria-
Stafford-Spotsylvania-King George-
Central and Southeast Prince William/Manassas/Manassas Park-
117 PM EDT Mon Aug 10 2026

This Hazardous Weather Outlook is for the Maryland portion of the
Chesapeake Bay, Tidal Potomac River, and I-95 corridor through
central Maryland, northern Virginia, and District of Columbia.

.DAY ONE...This Afternoon and Tonight

Severe Thunderstorm Watch Number 555 is in effect for the entire
area except St. Mary's County until 9 PM.

Scattered severe thunderstorms are possible this afternoon and
evening. Damaging wind gusts are the primary hazard.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Additional severe thunderstorms capable of producing damaging
winds are possible Tuesday.

.SPOTTER INFORMATION STATEMENT...

Skywarn Spotter Network has been activated.

MDZ003>006-503-505-507-VAZ025>031-036>040-050-051-501-502-505>508-
526-WVZ050>053-055-111000-
Washington-Frederick-Carroll-Northern Baltimore-
Northwest Montgomery-Northwest Howard-Northwest Harford-Augusta-
Rockingham-Shenandoah-Page-Warren-Clarke-Nelson-Albemarle-Greene-
Madison-Rappahannock-Orange-Culpeper-Northern Fauquier-
Southern Fauquier-Western Loudoun-Eastern Loudoun-
Northern Virginia Blue Ridge-Central Virginia Blue Ridge-
Northwest Prince William-Hampshire-Morgan-Berkeley-Jefferson-
Hardy-
117 PM EDT Mon Aug 10 2026

This Hazardous Weather Outlook is for portions of eastern West
Virginia, northern and central Virginia, and central and western
Maryland.

.DAY ONE...This Afternoon and Tonight

Severe Thunderstorm Watch Number 555 is in effect for the entire
area until 9 PM.

Scattered severe thunderstorms are possible this afternoon and
evening. Damaging wind gusts are the primary hazard.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Additional strong to severe thunderstorms capable of producing
damaging winds are possible Tuesday.

.SPOTTER INFORMATION STATEMENT...

Skywarn Spotter Network has been activated.

MDZ501-502-509-510-VAZ503-504-WVZ501>506-111000-
Extreme Western Allegany-Central and Eastern Allegany-
Western Garrett-Eastern Garrett-Western Highland-Eastern Highland-
Western Grant-Eastern Grant-Western Mineral-Eastern Mineral-
Western Pendleton-Eastern Pendleton-
117 PM EDT Mon Aug 10 2026

This Hazardous Weather Outlook is for the Allegheny Front
counties in western Maryland, eastern West Virginia, and Highland
County Virginia.

.DAY ONE...This Afternoon and Tonight

Severe Thunderstorm Watch Number 555 is in effect for the entire
area until 9 PM.

Scattered thunderstorms are possible this afternoon and evening.
Damaging wind gusts and isolated instances of flash flooding are
possible.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Additional severe thunderstorms capable of producing damaging
winds and isolated instances of flash flooding are possible
Tuesday.

.SPOTTER INFORMATION STATEMENT...

Skywarn Spotter Network has been activated.

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>