Quiet, Cloudy Calm Before Isaias Remnants Arrive Sunday

Good morning. Today is the calm you bank for later — NWS Baltimore/Washington (issued 3:37 AM) and NWS Mount Holly (3:38 AM) both describe a dry, mostly cloudy Saturday with high pressure still nominally in charge before it slides east. Enjoy it, because the remnants of Hurricane Isaias are organizing their approach, and NWS Wakefield (3:09 AM) now has rain, wind, and a Slight Risk of severe weather on the board for Sunday. Today itself is unremarkable — that’s the whole point.

Timing: Today Into Tonight

• Early morning (now–10 AM): Patchy clouds, light winds, cool start statewide — 47–55° depending on where you wake up.
• Midday–afternoon: Mostly cloudy skies build in from the west as high pressure eases offshore. Dry everywhere. Highs mostly upper 60s to mid 70s.
• Evening: Clouds thicken further, winds turn more easterly ahead of the approaching system. Still dry for most of Maryland through sunset.
• Late tonight (after ~midnight, strongest west/south): Rain chances start to climb overnight, especially in Western Maryland and along the Potomac corridor, as the leading edge of Isaias’ moisture noses in. This is the overnight shift into Sunday’s main event — not today’s story, but worth having the umbrella staged by the door.

Region by Region

Western Maryland

Garrett (Deep Creek, Oakland): High near 63°, up from an overnight low around 47°. Mostly cloudy, winds light out of the east (3–14 mph). Essentially rain-free today — only a 1% chance — but that’s the calm before a soggy Saturday night, when showers move in and odds jump to 87%, lows near 50°. Allegany (Cumberland): Mild for the valley, high around 68°, light east winds, dry through the day. Saturday night turns wet fast — rain shower chances spike to 97%, with a low near 54°.

Northern & Central Maryland

Washington County (Hagerstown): High around 71°, mostly cloudy, light easterly breeze, essentially dry (2%). Clouds thicken into evening; rain arrives overnight with an 83% chance and a low around 57°. Frederick: Same story — high near 71°, dry by day, then rain develops Saturday night (77% chance), low around 58°. Carroll: Tracking with Frederick’s numbers, high in the low 70s, dry today, wet overnight.

Baltimore Metro

Baltimore City & County, Harford, Howard, Anne Arundel: High around 72°, mostly cloudy skies, light northeast winds (1–9 mph), and only a 1% rain chance — a genuinely nice Saturday for yard work or the farmers market. Clouds increase through the afternoon. Overnight, rain chances climb to roughly 53% with a low near 61° as the approach of Isaias’ remnants gets underway. Note: Anne Arundel is under a Coastal Flood Watch (see Hazards below) tied to Sunday’s tidal cycle, not today.

DC Suburbs

Montgomery, Prince George’s: High near 70°, mostly cloudy, light east winds. Dry through the day (2% chance), but rain showers become likely tonight — 66% chance, low near 59°, as the system’s outer moisture arrives from the south.

Southern Maryland

Charles, Calvert, St. Mary’s: High around 71°, mostly cloudy, light easterly wind, dry by day. Rain moves in overnight with an 80% chance and a low near 61° — Southern Maryland gets going on the wet pattern a bit earlier than areas farther north.

Upper Eastern Shore

Cecil, Kent, Queen Anne’s, Talbot, Caroline: High near 73°, mostly cloudy, light east winds. Today stays dry, but confidence in overnight rain is higher here — 62% chance and rain likely by the back half of the night, low around 60°.

Lower Eastern Shore

Dorchester, Wicomico, Somerset: Warmest spot on the map today, high near 74°, mostly cloudy, light east wind. Showers arrive overnight — 75% chance, transitioning from light rain to rain showers, low around 63°.

Ocean City & the Coast

Worcester (Ocean City/Assateague): High only in the upper 60s (gridpoint near 68°), mostly cloudy, east winds 7–13 mph. Surf is tame today — 1 to 3 feet, rip current risk low, water in the mid 60s. High tide at the Ocean City Fishing Pier is 7:44 AM, low tide 2:07 PM. Quiet beach day if you don’t mind grey skies. That changes abruptly Sunday: surf jumps to 5–8 feet, rip current risk goes to high, and winds turn breezy out of the southeast around 25 mph as rain moves in.

Active Hazards

Wind Advisory (Moderate): Western Garrett County (along with Western Grant and Western Pendleton Counties, WV) — downsloping easterly winds over the Alleghenies as the circulation from Isaias’ remnants strengthens. Timing runs late tonight into Sunday morning, with peak gusts forecast 40–50 mph in the higher terrain. Secure anything loose up on the mountain before you turn in tonight.

Coastal Flood Watch (Moderate): Anne Arundel County — minor tidal flooding is possible with Sunday morning’s high tide cycle as onshore flow and the approaching low combine to push water levels up along the Bay shoreline. Not a concern today, but low-lying waterfront roads and docks in Anne Arundel should be watched starting Sunday morning.

No hazardous weather is expected today itself, per NWS Baltimore/Washington’s Hazardous Weather Outlook — the active alerts above are specifically tied to Sunday’s system.

Severe Weather & Flooding Outlook (Sunday)

This is where the forecast gets interesting, even though it’s not today’s problem. As Isaias’ remnants track into a strengthening mid-level low, forcing increases Saturday night into Sunday, with tropical moisture (PWATs at or above 2 inches) surging in after midnight. NWS Baltimore/Washington has bumped rainfall totals up to 1.5–2.5 inches region-wide, with locally higher amounts of 3–4 inches possible, especially where easterly flow runs into the Blue Ridge and enhances totals orographically. No Flood Watch has been issued yet, but it’s being watched closely.

Severe weather is also now a real concern for Sunday afternoon. A surface wave of low pressure tracks through the area, and strong wind shear plus large hodographs could support a few organized, rotating storms — tornadoes and damaging wind gusts are the primary threats, mainly favored east of the Blue Ridge. SPC has placed a Slight Risk (level 2 of 5) just south of Maryland, with a Marginal Risk extending north to around the Maryland/Pennsylvania line. Confidence on timing is moderate; confidence on magnitude of instability (how juiced the atmosphere actually gets) is lower. We’ll have more detail in Sunday’s editions.

Winds & Bay/Marine

Winds today are light and generally out of the east or northeast across the state, 1 to 10 mph — nothing disruptive. That changes markedly tonight into Sunday as easterly flow strengthens ahead of the system, with gusts building toward 20–30 mph in the lowlands and 40–50 mph possible in the Alleghenies and Blue Ridge under the Wind Advisory. On the water, a Gale Watch remains in effect farther south per NWS Wakefield’s bulletin, and a Small Craft Advisory has been issued for northern New Jersey coastal waters by NWS Mount Holly — boaters on the Chesapeake should plan for deteriorating conditions by Sunday, even though today’s Bay waters stay relatively settled.

Overnight Lows by Zone

Looking Ahead

Sunday: The main event. Widespread rain, likely 1.5–2.5 inches with locally higher totals, breezy to windy conditions statewide, and a legitimate severe weather threat (tornadoes, damaging gusts) Sunday afternoon, mainly east of the mountains. Minor to nuisance tidal flooding is possible along the Bay, especially Anne Arundel, with the morning high tide. Columbus Day (Monday): Rain tapers and pushes offshore as the remnants exit, but it stays humid and warm with highs reaching the low-to-mid 70s across most of the state — not much sunshine returns right away despite the drying trend. Expect a brief warmup toward 80° by Tuesday before cooler, drier fronts push through later in the week.

Data: NWS Baltimore/Washington, Mount Holly & Wakefield. — MD Weather Alerts brings you Maryland’s weather, county by county, because the sky doesn’t read state lines but your plans sure depend on them. Stay dry out there, and keep an eye on Sunday.