Maryland is returning to a humid and unsettled weather pattern today, with periods of showers and thunderstorms expected through the morning and additional scattered development possible during the afternoon and evening.
The primary concern is not a widespread severe-weather outbreak. Instead, the main hazard will be slow-moving or repeating downpours capable of producing urban flooding, ponding and rapidly reduced visibility.
A Flood Watch remains in effect through 11:00 AM for the Washington metro and portions of the Interstate 95 corridor.
Statewide Overview
A warm front lifting north through the Mid-Atlantic will draw deeper tropical moisture into Maryland.
Periods of rain and embedded thunderstorms may cross central and eastern Maryland during the morning. The exact corridor of heaviest rain remains uncertain, but the Washington suburbs, Baltimore–Washington corridor and portions of the Eastern Shore have the greatest chance of experiencing rainfall during the commute.
A relative lull may develop around midday. Additional scattered showers and thunderstorms are then expected during the afternoon and evening as daytime heating interacts with the humid air mass.
Not every community will receive a storm during the afternoon. Where storms develop, however, rainfall may be intense.
Wednesday Morning Commute
Rain will not fall continuously everywhere, but commuters should prepare for sudden downpours.
The most likely corridor for disruptive morning rainfall extends from Southern Maryland and the Washington suburbs northward into central Maryland. Additional showers and thunderstorms may affect the Eastern Shore.
Potential morning impacts include:
• Water covering low-lying and poorly drained roads
• Reduced visibility during heavy rain
• Longer braking distances
• Temporary lane flooding in urban areas
• Lightning near outdoor work and school activities
• Low clouds and patchy fog
Conditions should generally be quieter across Garrett and Allegany counties, although patchy fog is possible in valleys.
Never attempt to drive through a flooded roadway.
Midday Forecast
Morning showers should become more scattered between approximately 10:00 AM and 1:00 PM.
Some breaks in the cloud cover may develop, especially across Western and northern Maryland. Any sunshine will increase instability and support another round of scattered thunderstorms later in the day.
Temperatures will climb into the 80s while humidity rises.
Wednesday Afternoon
Scattered showers and thunderstorms are expected to redevelop between approximately 1:00 PM and 7:00 PM.
Storm placement will depend heavily on how quickly morning clouds and rain diminish. Areas receiving prolonged morning rain may remain somewhat more stable, while locations seeing afternoon sunshine may experience greater storm development.
The main afternoon hazards will be:
• Torrential rainfall
• Localized flash flooding
• Frequent lightning
• Sudden wind gusts
• Briefly reduced visibility
A storm could become strong, but the overall severe-weather threat remains limited and conditional.
Wednesday Evening and Overnight
Scattered storms may continue into the early evening before gradually diminishing.
Warm, humid and mostly cloudy conditions will continue overnight. Patchy fog may develop where significant rain falls during the day.
Overnight lows will generally range from the upper 60s in Western Maryland to the middle 70s around Baltimore, Washington, Southern Maryland and the Eastern Shore.
County-by-County Forecast
Garrett County
Patchy valley fog is possible this morning. Expect clouds and occasional sunshine, followed by scattered afternoon or evening showers and thunderstorms.
High: 79–82°.
Tonight: Partly to mostly cloudy with a lingering shower possible. Low around 64–67°.
Allegany County
The morning should be quieter than central and eastern Maryland. Clouds increase during the day, with scattered afternoon or evening storms.
High: 82–85°.
Tonight: Humid with patchy fog. Low around 65–68°.
Washington County
Scattered morning showers are possible, followed by a temporary midday lull. Additional thunderstorms may develop during the afternoon.
High: 82–85°.
Tonight: Mostly cloudy and humid. Low around 69–72°.
Frederick County
Periods of morning rain or an embedded thunderstorm may affect the commute. Additional scattered storms are possible this afternoon.
High: 83–86°.
Tonight: Mostly cloudy with patchy fog. Low around 69–72°.
Carroll County
Mostly cloudy with morning showers possible. A few afternoon or evening thunderstorms may develop.
High: 83–86°.
Tonight: Warm and humid. Low around 69–72°.
Baltimore County
Periods of morning rain and isolated thunderstorms are possible. Heavy rain could produce ponding, especially in urbanized eastern and southern portions of the county.
A midday lull may be followed by scattered afternoon storms.
High: 84–87°.
Tonight: Mostly cloudy and humid. Low around 72–75°.
Baltimore City
Morning rain may be locally heavy. Storm drains and underpasses may experience temporary flooding if an intense downpour crosses the city.
Additional scattered thunderstorms remain possible during the afternoon and evening.
High: 85–87°.
Tonight: Humid with a low around 74–76°.
Harford County
Morning showers are possible, particularly across southern and eastern portions of the county. Scattered storms may develop during the afternoon.
High: 83–86°.
Tonight: Mostly cloudy. Low around 70–73°.
Cecil County
Cloudy and humid with morning showers possible. Additional isolated or scattered thunderstorms may develop later today.
High: 84–87°.
Tonight: Mostly cloudy with a low around 71–74°.
Montgomery County
Periods of showers and thunderstorms may affect the morning commute. Rain could be heavy enough to cause urban and poor-drainage flooding.
A partial lull is possible around midday before scattered afternoon storms return.
High: 84–87°.
Tonight: Warm and humid. Low around 71–74°.
Howard County
Morning rain may be locally heavy, particularly across the more urbanized Interstate 95 corridor.
Additional scattered thunderstorms are possible during the afternoon and evening.
High: 84–87°.
Tonight: Mostly cloudy. Low around 71–74°.
Prince George’s County
Periods of rain and thunderstorms are expected during the morning. Watch for ponding along urban roads, low-lying areas and locations near small streams.
Additional scattered storms may redevelop this afternoon.
High: 84–87°.
Tonight: Humid with a low around 72–75°.
Anne Arundel County
Morning showers and thunderstorms are possible. Heavy rain may briefly reduce visibility along Interstate 97, Route 50 and roads near Annapolis.
Scattered afternoon storms may also affect the Chesapeake Bay.
High: 83–86°.
Tonight: Mostly cloudy and humid. Low around 73–76°.
Charles County
Periods of morning rain and thunderstorms are possible. A midday lull may be followed by additional scattered afternoon storms.
High: 82–85°.
Tonight: Humid with a low around 71–74°.
Calvert County
Morning showers and isolated thunderstorms are possible. Scattered storms may redevelop during the afternoon or early evening.
High: 82–85°.
Tonight: Mostly cloudy. Low around 72–75°.
St. Mary’s County
A morning shower or thunderstorm remains possible as the warm front moves north. Afternoon storm coverage should be lower than Tuesday, but an isolated downpour may still occur.
High: 82–85°.
Tonight: Warm and humid. Low around 72–75°.
Kent County
Mostly cloudy with periods of morning rain possible. Additional isolated or scattered storms may develop during the afternoon.
High: 84–87°.
Tonight: Mostly cloudy. Low around 72–75°.
Queen Anne’s County
Morning showers and an embedded thunderstorm are possible. A few additional storms may develop later in the day.
High: 84–87°.
Tonight: Humid with a low around 73–76°.
Talbot County
Periods of rain may affect the morning. Scattered afternoon storms remain possible, with localized heavy rain under the strongest cells.
High: 84–87°.
Tonight: Mostly cloudy. Low around 73–76°.
Caroline County
Morning showers are possible, followed by scattered afternoon thunderstorms.
High: 85–88°.
Tonight: Warm and humid. Low around 72–75°.
Dorchester County
Showers and a few thunderstorms may affect the morning. Storm coverage should become more isolated or scattered during the afternoon.
High: 84–87°.
Tonight: Mostly cloudy. Low around 73–76°.
Wicomico County
Morning showers and thunderstorms are possible. Afternoon storm coverage should be less extensive than Tuesday, although isolated heavy rain remains possible.
High: 85–88°.
Tonight: Humid with a low around 73–76°.
Somerset County
Periods of rain or an embedded thunderstorm may affect the morning. Isolated afternoon storms remain possible.
High: 84–87°.
Tonight: Mostly cloudy. Low around 73–76°.
Worcester County
Morning showers and a thunderstorm are possible. Conditions should become more scattered during the afternoon, but another isolated storm may develop.
Inland high: 85–88°.
Ocean City high: 81–84°.
Tonight: Mostly cloudy and humid with lows in the middle 70s.
Rainfall and Storm Timing
4–8 AM
Rain and embedded thunderstorms may spread through the Washington suburbs, central Maryland and parts of the Eastern Shore.
8–11 AM
The morning flooding concern continues, especially around urban and poor-drainage locations.
11 AM–2 PM
Rain becomes more scattered. Some communities may experience a temporary dry period.
2–7 PM
Additional scattered thunderstorms develop. The exact coverage will depend on morning rainfall and cloud cover.
After 7 PM
Storms gradually become more isolated, although an evening thunderstorm remains possible.
Flooding Risk
Maryland is under a localized rather than uniform flooding threat.
Communities receiving repeated showers or a slow-moving thunderstorm may experience:
• Rapid ponding
• Flooded underpasses
• Overflowing drainage systems
• Rapid rises on small streams
• Water covering rural low-water crossings
Urbanized portions of Montgomery, Prince George’s, Howard, Baltimore and Anne Arundel counties deserve particular attention during the morning.
Severe Weather Risk
A widespread severe-weather outbreak is not expected.
High atmospheric moisture and relatively weak steering winds favor slow-moving downpours more than organized damaging-wind storms.
An isolated storm may still produce a strong wind gust. Lightning will be a hazard with every thunderstorm.
Wind Forecast
Winds will generally turn south to southwest at approximately 5–12 mph.
Localized gusts above 30 mph are possible near thunderstorms.
Fog and Visibility
Patchy fog and low cloud cover are possible during the morning, especially:
• Western Maryland valleys
• Areas receiving overnight rain
• Rural locations near rivers and streams
• Lower Eastern Shore
Visibility may fall sharply inside heavy rain.
Chesapeake Bay and Tidal Potomac
Southerly winds generally remain below widespread Small Craft Advisory criteria during the day.
Thunderstorms may create localized hazardous conditions, including:
• Frequent lightning
• Sudden gusty winds
• Rapid visibility reductions
• Locally rough and confused water
Special Marine Warnings may be issued if stronger storms move across the waters.
Coastal and Beach Conditions
Ocean City and Assateague will remain warm and humid with morning showers possible and an isolated afternoon thunderstorm.
No significant coastal storm is expected. Beach visitors should still check the latest rip-current statement before entering the water and remain near lifeguards.
Tidal Flooding
Southerly flow will begin increasing water levels along the Chesapeake Bay and tidal Potomac.
Minor coastal flooding may become possible at sensitive locations during later high-tide cycles, particularly around Annapolis and other historically vulnerable shorelines. Confidence in exact water levels remains limited.
Heat and Humidity
Temperatures will remain near seasonal levels, but humidity will increase substantially.
Most afternoon heat-index readings should range from the upper 80s to lower 90s. Heat Advisory criteria are not expected today.
Hotter conditions are likely later this week.
Air Quality
No major statewide air-quality emergency is indicated in the available guidance.
Localized Moderate air-quality conditions remain possible around the Baltimore–Washington corridor. Rain and cloud cover may limit ozone formation during portions of the day.
People unusually sensitive to air pollution should review their local reading before prolonged outdoor exertion.
Winter Weather
There are no winter-weather concerns anywhere in Maryland.
Tropical Weather
No direct tropical cyclone impact is expected in Maryland today.
The humid air contributing to the heavy-rain potential is tropical in character, but it is not associated with a direct tropical-system landfall.
Looking Ahead
Thursday through the weekend will remain warm, increasingly humid and unsettled.
Daily afternoon and evening thunderstorms will be possible. The risk for localized flash flooding and isolated damaging wind gusts will vary from day to day.
Friday currently appears capable of becoming one of the more active days, but confidence in exact storm timing remains limited.
Temperatures may return to the upper 80s and lower 90s later this week, with heat-index values approaching or exceeding 100° in some locations by the weekend.