A Gorgeous, Dry Wednesday Before Thursday’s Storm Threat

Good morning. Today is the calm before the pattern change — NWS Baltimore/Washington (issued 2:11 AM) and NWS Mount Holly (4:26 AM) both have high pressure settling in for a mostly sunny, comfortably dry Wednesday across Maryland, with just some patchy morning fog to sweep out by mid-morning. Enjoy it, because Thursday brings a stronger cold front, increasing shower and thunderstorm chances, and — per the latest LWX discussion — a slight uptick in severe weather potential near and east of I-95. NWS Wakefield (5:48 AM) echoes the same story for the southern counties: seasonably warm, noticeably less humid today, then unsettled Thursday through the weekend.

Timing At A Glance

• Early morning (now–8 AM): Patchy fog possible, especially across the Eastern Shore, southern Maryland, and low-lying spots. Should mix out by mid-morning.
• Midday–afternoon: Sunshine builds, dry and comfortable with lower humidity — the pick of the week.
• Evening: Clear to partly cloudy skies persist; clouds begin increasing overnight, mainly toward Washington and Garrett counties, as the cold front approaches from the west.
• Overnight into early Thursday: Shower chances tick up near and west of I-81 after midnight, with showers possible area-wide by Thursday morning.

County-by-County Breakdown

Western Maryland

Garrett (Deep Creek/Oakland): High near 75° — comfortably mild for the mountains — under mostly sunny skies, light west winds 2-8 mph. Overnight lows dip to around 55° with patchy fog developing again. Thursday brings a much higher (81%) shower/storm chance as the front arrives first here.
Allegany (Cumberland): High around 84° with patchy morning fog giving way to sunshine, light west winds. Low tonight near 64° under mostly cloudy skies with fog redeveloping. Thursday’s rain chances jump to 80%.

Northern & Central Maryland

Washington County (Hagerstown): Sunny after early patchy fog, high near 87°, light southwest winds. Clear overnight low around 62°, becoming partly cloudy with rain chances rising (30%) late tonight ahead of Thursday’s more organized showers and storms (79%).
Frederick: High near 88° under sunny skies after morning fog burns off, calm to light west winds. Overnight low around 63° with patchy fog. Thursday’s storm chances climb to 78%, with the potential for stronger cells given favorable instability.
Carroll: Sharing Frederick’s gridpoint — high near 88°, sunny, low near 63° overnight with patchy fog possible before Thursday’s unsettled pattern arrives.

Baltimore Metro

Baltimore City & County: A stunner of a day — high near 90°, sunny, light west winds 1-6 mph. Clear, comfortable overnight low around 68°, partly cloudy. This is the region NWS flags for the highest severe potential Thursday afternoon, as the front is expected to stall near I-95 during peak heating.
Harford: Sharing the Baltimore gridpoint — sunny, near 90° today, low around 68° tonight. Southeast Harford falls within the marine/tidal outlook area, though no hazards are in effect.
Howard: Same story — sunny and near 90°, calm winds, comfortable overnight in the upper 60s.
Anne Arundel: High near 90° with sunshine and light winds off the Bay; overnight low around 68°, partly cloudy. Boaters get a quiet day on the water before Thursday’s unsettled turn.

DC Suburbs

Montgomery: Sunny, high near 88°, light northwest winds. Clear overnight low around 68°. Thursday storm chances run 62%, likely stronger toward the District line.
Prince George’s: Same gridpoint as Montgomery — sunny, near 88° today, low around 68° tonight, calm and pleasant before Thursday’s likely showers and storms.

Southern Maryland

Charles, Calvert, St. Mary’s: All sharing the Prince Frederick gridpoint — sunny and warm with a high near 89°, light northwest winds around 3 mph. Mostly clear overnight, low near 71°. Thursday’s rain/storm chances climb to 55%, becoming likely (72%) Thursday night.

Upper Eastern Shore

Cecil, Kent, Queen Anne’s, Talbot, Caroline: Sharing the Easton gridpoint — sunny skies, high near 87°, light northwest winds. Mostly clear overnight with a low around 72°, partly cloudy. Thursday brings a 70% shower/storm chance, becoming likely (76%) Thursday night.

Lower Eastern Shore

Dorchester, Wicomico, Somerset: Sharing the Salisbury gridpoint — patchy fog early, then mostly sunny with a high near 89°, light northwest to west winds. Mostly clear tonight, low near 71°. Thursday’s shower/storm chance runs 63%, likely (60%) again Thursday night.

Ocean City & the Coast

Patchy fog early, then mostly sunny with a high near 81° — noticeably cooler at the coast thanks to the sea breeze, with east winds 2-7 mph becoming southeast in the afternoon. Rip current risk is Low and surf height runs around 2 feet, with UV index Very High — bring the sunscreen. Water temps sit in the upper 70s. Low tide at the Ocean City Fishing Pier is 6:53 AM, high tide 1:16 PM. Tonight stays mostly clear, low near 73°. Thursday turns more active along the coast too, with showers likely and a chance of thunderstorms after 4 PM, high near 83°.

Active Hazards

No watches, warnings, or advisories are in effect for Maryland at this time. The LWX Hazardous Weather Outlook confirms no hazardous weather is expected today or tonight across the I-95 corridor, central Maryland, and the Chesapeake Bay/tidal Potomac waters.

Severe & Flooding Outlook — Looking to Thursday

Nothing severe is expected today, but Thursday bears watching closely. LWX highlights a scenario where a cold front stalls near I-95 during peak afternoon heating, with strong instability (CAPE near or exceeding 2000 J/kg) building east of the boundary while a powerful 80-90+ kt upper jet swings overhead. That combination supports strong to severe thunderstorms — capable of damaging straight-line winds, a few embedded spin-ups, and even some hail — especially near and east of I-95 into the Baltimore-Washington corridor and points east. For now, this sits in the Marginal (level 1 of 5) severe category, but LWX notes a

MD Weather Alerts · issued 6:00 AM, Wednesday, August 19