Good morning. Buckle up — this is the kind of August day where you keep one eye on the sky and one on the radar app. NWS Baltimore/Washington (2:19 AM update) and NWS Mount Holly (3:16 AM) both describe a very active pattern: thunderstorm complexes already rolling into Garrett County at daybreak, with a Flash Flood Watch in effect for the western mountains, and waves of showers and storms spreading east across the entire state through the afternoon, evening, and overnight. Some of these storms could turn severe, with damaging wind gusts, a tornado or two, and localized flash flooding all on the table. This isn’t a washout day everywhere, but it is an all-day, watch-the-radar day.
Timing: Hour by Hour
- Daybreak–9 AM: Thunderstorm complex (the same one that triggered flash flood warnings and water rescues overnight in southeastern Ohio) crosses into Garrett County. Training storms (repeated cells moving over the same area) are a real concern here, with rates that have produced 3 inches of rain in an hour upstream.
- 9 AM–Noon: Activity works across Allegany County and the western mountains generally lose some punch crossing the ridges, but a convergence zone keeps the flood threat alive from Allegany down toward the WV border. Meanwhile scattered showers develop toward central Maryland as moisture surges in ahead of a warm front.
- Noon–4 PM: A relative lull is possible statewide as one wave exits and the next builds — though isolated storms can still fire almost anywhere given how saturated the atmosphere is.
- 4 PM–10 PM: The main event. A second, stronger shortwave (currently over Illinois) arrives, with widespread showers and thunderstorms expected across central Maryland, the Baltimore/DC corridor, and the Eastern Shore. This is the window for strong to severe storms — damaging wind gusts are the top concern, with a tornado or two possible, especially where storms interact with the lifting warm front.
- 10 PM–overnight: Low pressure tracks through, keeping showers and thunderstorms going overnight, only gradually winding down toward daybreak Monday. Localized 3–6 inch rainfall totals are possible if any spot gets stuck under repeat storms.
Region by Region
Western Maryland
Garrett (Deep Creek/Oakland): High near 76°, low near 64° tonight. Showers and thunderstorms arrive at daybreak and continue through the day (96% chance) into tonight (83%). Winds light, southwest 6–10 mph. This is ground zero for the flash flood threat — Deep Creek Lake area and low-lying roads could see fast-rising water.
Allegany (Cumberland): High near 82°, low near 70°. Showers and thunderstorms nearly all day (97%) and overnight (83%). Winds south around 1–6 mph. Downtown Cumberland’s flood-prone spots bear watching if training storms set up along the convergence zone.
Northern & Central Maryland
Washington County (Hagerstown): High near 82°, overnight low 71°. Showers and thunderstorms likely (95%) today, continuing scattered tonight (90%). South winds around 10 mph.
Frederick County: High near 80°, low 71°. Showers and storms 91% today, 90% tonight. South winds 5–10 mph.
Carroll County: Sharing Frederick’s numbers — high near 80°, low near 71°, same widespread shower/storm coverage through the day and night.
Baltimore Metro
Baltimore City & County, Harford, Howard, Anne Arundel: High near 82°, low near 74°. Showers and thunderstorms 87% today and 87% again tonight — essentially an all-day, all-night threat. South winds 5–12 mph. Any storm that turns severe this afternoon/evening brings the wind-damage and localized flooding risk right into the Baltimore Beltway corridor and Harbor area.
DC Suburbs
Montgomery & Prince George’s: High near 81°, low near 71°. Showers and thunderstorms 83% today, increasing to 86% tonight. Winds south to southwest 2–10 mph. Poor-drainage spots along the Beltway and in Silver Spring/College Park are the ones to watch for ponding.
Southern Maryland
Charles, Calvert, St. Mary’s: High near 84°, low near 72°. Scattered showers build through the day (56%) then scattered storms tonight (76%). South winds 3–14 mph, gusty at times. A bit drier start here than points north, but the evening/overnight window still carries a real storm threat.
Upper Eastern Shore
Cecil, Kent, Queen Anne’s, Talbot, Caroline: High near 82°, low near 73°. Showers and thunderstorms likely today (71%), becoming widespread tonight (90%). South winds 5–15 mph. Farm fields already saturated from prior rounds could see standing water again.
Lower Eastern Shore
Dorchester, Wicomico, Somerset: High near 84°, low near 72°. Partly sunny start with a lower daytime chance (36%), but showers and thunderstorms move in by tonight (78%). South winds 8–12 mph. Salisbury and points south hold off longest before the evening storms arrive.
Ocean City & the Coast
Worcester County: High near 81°, overnight low near 74°. Mostly sunny until early afternoon, then clouds increase with a chance of showers (29% today), and showers/thunderstorms become likely tonight (79%) with southeast-to-south winds 6–15 mph, gusting higher near storms. Surf around 2 feet, rip current risk low, water temperature upper 70s. High tide at Ocean City Fishing Pier 10:51 AM, low tide 5:08 PM. Beach day works fine through the morning — watch the sky by mid-afternoon.
Active Hazards
Flood Watch (in effect today into tonight): Western Garrett and Eastern Garrett Counties, and Extreme Western Allegany and Central/Eastern Allegany Counties. Repeated rounds of heavy thunderstorms, with localized rainfall rates capable of producing 3 to 6 inches on a training/repeat basis, could lead to scattered to numerous flash flooding, especially in poor-drainage and previously-saturated areas. (This watch also extends into nearby West Virginia counties, but the Maryland impact is centered on Garrett and Allegany.)
No other formal watches or warnings are posted for Maryland as of this writing, but NWS Baltimore/Washington notes additional Flood Watches may be issued later today if the heaviest rain axis becomes clearer — stay tuned through the afternoon.
Severe & Flooding Threat
Confidence is high that today will feature multiple rounds of showers and thunderstorms statewide, with the greatest severe risk arriving with the afternoon-into-evening wave. Damaging wind gusts are the primary concern as storms organize into more linear clusters, but the environment (strong low-level winds, high moisture, a lifting warm front) also supports a few tornadoes, particularly if a storm tracks along or interacts with the frontal zone. Flash flooding is the other headline threat — precipitable water values around 2 to 2.25 inches (well above normal for mid-August) mean any storm that stalls or trains over the same area can produce dangerous rainfall rates. This is highest-risk in Garrett and Allegany Counties this morning, but the potential for locally heavy, flood-prone downpours exists anywhere in the state today, including in urban Baltimore and DC-suburb areas with poor drainage.
Heat, Humidity & Winds
Dew points climb into the low 70s behind the warm front, so it’ll feel sticky and tropical for mid-August even with highs generally in the 80s (upper 70s in the mountains). No heat advisory is in place for Maryland today, but the air mass is plenty muggy — expect that heavy, soupy feel especially in the Baltimore-DC corridor and Southern Maryland by afternoon. Winds run generally south to southwest at 5–15 mph, occasionally higher and gusty near thunderstorm outflows, with Ocean City seeing southeast winds up to 15 mph and higher gusts as storms approach tonight.
Chesapeake Bay & Marine
The Bay and tidal Potomac are included in today’s Hazardous Weather Outlook for the multi-round thunderstorm threat — boaters on the Chesapeake, Patapsco, Patuxent, Choptank, and Tangier Sound should expect sudden gusty winds and lightning with any passing storm cell, with the best chance of building seas and squally conditions during the afternoon-evening wave.
Tonight’s Lows by Zone
| Zone | Overnight Low |
| Western Mountains (Garrett) | ~65° |
| Cumberland/Hagerstown | ~70–71° |
| Frederick/Carroll | ~71° |
| Baltimore | ~74° |
| DC Suburbs | ~71° |
| Southern Maryland | ~72° |
| Eastern Shore | ~72–73° |
| Ocean City | ~74° |
Looking Ahead
Monday: Hotter and more humid statewide, with highs near 90° in the Baltimore area and Southern Maryland, upper 80s across Washington, Frederick, and Carroll Counties, and mid-to-upper 80s from Cumberland east to the Eastern Shore and Ocean City. Mostly sunny for much of the day, but isolated afternoon/evening showers and thunderstorms are still possible ahead of the next cold front. Tuesday looks like the best day of the stretch — sunny and comfortably drier with highs in the mid-to-upper 80s. Thunderstorm chances return again Wednesday night into Thursday as another front approaches, with unsettled, showery conditions possibly lingering into the weekend as that front stalls nearby.
Data: NWS Baltimore/Washington, Mount Holly & Wakefield.
Stay dry out there, Maryland — MD Weather Alerts will keep an eye on the radar through the day and let you know if watches are upgraded.