⚠️ Flood watch extended across northern Maryland and Pennsylvania
Saturday, June 14, brought a dangerous weather setup similar to the one seen on Friday. A stationary frontal boundary stalled over north-central Maryland is combining with moist air from the Atlantic and afternoon heating, leading to very slow-moving thunderstorms. These storms have limited upper-level winds, meaning they remain nearly stationary, dumping torrential rain over the same areas for hours.
Rainfall totals could range between 1 and 3 inches (25 to 75 mm), with some localized pockets reaching 5 inches (125 mm). The flooding risk is particularly high for Central Maryland, especially south and west of Baltimore, but cells are likely to drift east, potentially impacting the entire Baltimore Metro, Delmarva Peninsula, and parts of southeastern Pennsylvania.
⛈️ Severe storm outlook: intense rainfall over damaging winds
According to NOAA, while some thunderstorm cells might generate wind gusts up to 60 mph (97 km/h), the main threat remains the slow speed of storm movement and the volume of rainfall they unload over affected zones. There’s a real danger that isolated cells could linger for hours, leading to flash flooding.
Important terms to know:
- WATCH: Means there is potential for severe weather within a 4 to 6-hour window. It is a preemptive alert based on conditions.
- WARNING: Issued when a storm is actively occurring and being tracked. This alert typically focuses on specific towns and lasts about 45 minutes.
🌬️ Winds and smoke: air quality compromised by New Jersey wildfires
An easterly wind flow has transported low-level smoke from an ongoing wildfire in New Jersey into the Mid-Atlantic region. The air is noticeably hazy in parts of eastern Maryland and southern Pennsylvania, further complicating the situation. These winds also enhance storm development, pushing moisture inland and generating more instability.
Expect a split pattern: cooler conditions to the north and northeast, with warmer, more humid air to the southeast. This thermal contrast along the frontal boundary helps fuel stronger and more expansive thunderstorm clusters into the evening.
🕖 Storm timing and radar simulation: Saturday night into Sunday
Wind forecast for 7 PM shows strong convergence along the frontal zone, creating a focus for thunderstorm initiation and expansion. Simulations project storm clusters forming and growing between:
- 6 PM to 10 PM Saturday, with very heavy rain bands crossing Maryland and Pennsylvania
- Midnight to 2 AM, storms move toward the Delaware Bay and Delmarva
Radar simulation from 2 PM Saturday to 4 AM Sunday shows persistent storm activity along the boundary, mostly drifting east to southeast as cloud tops rise and cells mature.
🌤️ Father’s Day weather: cooler start, lingering showers
Sunday, June 15, which is Father’s Day, will start with cooler and more stable conditions, especially across northern areas. Morning lows will dip below 60°F (16°C) in rural zones, while some spotty showers remain possible—heavier rain threats will shift farther south into Virginia and southern Maryland.
Throughout the day, temperatures will stay mild, with afternoon highs likely ranging between 72°F and 78°F (22°C to 26°C) across most of the region.
📅 Looking ahead: wet pattern continues, heat returns by Thursday
Next week is forecast to include a chance of showers or thunderstorms each day, though not continuous all-day rain. By Thursday, a strong ridge may develop, triggering above-normal heat for the Mid-Atlantic.
NOAA’s Excessive Heat Outlook highlights the potential for temperatures to reach the low to mid 90s (34°C to 36°C) across Maryland, Delaware, and parts of New Jersey by late week.
