Maryland begins Saturday with another warm and humid morning after Friday evening’s round of thunderstorms.
Storm coverage today is expected to be lower than Friday, meaning many communities could remain dry for much of the day. However, a passing upper-level disturbance combined with stronger atmospheric wind shear may allow the storms that do develop to become better organized.
The primary concerns this afternoon and evening will be isolated damaging wind gusts and torrential rainfall, with localized flash flooding possible where storms repeatedly cross the same community. NWS Baltimore/Washington notes that while storm coverage should decrease compared with Friday, the potential intensity of an organized storm could be somewhat greater.
Saturday Morning
Most of Maryland will have a dry morning.
Patchy fog may develop before and shortly after sunrise in Western Maryland valleys and locations that received rain Friday evening.
Fog should gradually dissipate as temperatures rise.
By late morning, temperatures will already reach the 80s across central and eastern Maryland.
Midday
Most communities remain dry through lunchtime.
Temperatures climb toward the upper 80s and lower 90s, with high humidity making it feel closer to the middle or upper 90s.
Heat indices east of the Blue Ridge may approach 100°.
Saturday Afternoon
Thunderstorm development becomes possible after approximately 1–3 PM.
The earliest activity should favor Western Maryland and higher terrain. Additional isolated or scattered storms may then develop farther east.
Unlike Friday, storms should not be as numerous. Exact placement is therefore uncertain.
Saturday Evening
The most favored window for storms across central and eastern Maryland is approximately 4–9 PM.
Any stronger storm may produce:
- Damaging wind gusts
- Frequent lightning
- Torrential rainfall
- Localized flash flooding
- Brief power outages
- Sharply reduced visibility
Storm coverage gradually decreases after sunset.
County-by-County Forecast
Garrett County
Some early showers remain possible before a midday lull. Additional afternoon/evening storms may develop.
Highs: upper 70s to lower 80s.
Allegany County
Warm and humid with scattered afternoon/evening storms.
Highs: lower to middle 80s.
Washington County
Mainly dry morning. Scattered afternoon thunderstorms possible.
Highs: mid to upper 80s.
Frederick County
Hot and humid with thunderstorms possible late afternoon or evening.
Highs: upper 80s to around 90°.
Carroll County
Partly sunny and humid. A scattered late-day storm is possible.
Highs: upper 80s.
Baltimore County
Hot and humid. Scattered thunderstorms possible during the late afternoon/evening.
Highs: around 89–92°.
Baltimore City
Hot with highs around 90–93°.
A late-day thunderstorm may produce damaging wind and urban ponding.
Harford County
Hot and humid, with scattered afternoon/evening storms possible.
Highs: upper 80s to lower 90s.
Cecil County
Hot and humid with an isolated or scattered late-day thunderstorm.
Highs: around 89–92°.
Montgomery County
Mostly dry through early afternoon. A scattered thunderstorm may develop later.
Highs: around 90–93°.
Howard County
Hot and humid with an afternoon/evening storm chance.
Highs: around 89–92°.
Prince George’s County
Mainly dry through much of the day, then a late thunderstorm possible.
Highs: around 90–93°.
Anne Arundel County
Hot and humid with an isolated/scattered afternoon or evening storm.
Highs: upper 80s to around 91°.
Charles County
Mostly dry morning and midday. Late-day storm possible.
Highs: upper 80s to lower 90s.
Calvert County
Hot and humid near the Bay with an isolated late storm.
Highs: upper 80s.
St. Mary’s County
Mainly dry for much of the day with a late storm possible.
Highs: upper 80s to around 90°.
Kent County
Hot and humid with an isolated evening thunderstorm possible.
Highs: upper 80s to lower 90s.
Queen Anne’s County
Mostly dry early, with a late-day storm possible.
Highs: upper 80s to lower 90s.
Talbot County
Hot and humid with an isolated afternoon/evening storm.
Highs: upper 80s to around 90°.
Caroline County
Mostly sunny to partly cloudy with a late storm possible.
Highs: around 89–92°.
Dorchester County
Hot and humid with an isolated late-day thunderstorm.
Highs: upper 80s to around 90°.
Wicomico County
Mostly dry through the first part of the day. A stray afternoon/evening storm remains possible.
Highs: upper 80s to lower 90s.
Somerset County
Hot and humid with a limited late-day storm chance.
Highs: upper 80s.
Worcester County
Mostly sunny to partly cloudy with an isolated inland thunderstorm possible.
Inland highs: upper 80s to lower 90s.
Ocean City
Warm and humid with highs generally in the middle 80s.
The latest retrieved NWS surf-zone product carrying a Maryland rip-current category was not issued on August 7, so a Saturday rip-current category is not being stated as current in this forecast.
Temperature Breakdown
Western mountains: Upper 70s–lower 80s
Cumberland: Lower–middle 80s
Hagerstown/Frederick: Mid-upper 80s to around 90°
Baltimore/Washington corridor: 89–93°
Southern Maryland: Upper 80s–lower 90s
Eastern Shore: Upper 80s–lower 90s
Immediate Atlantic coast: Mid-80s
Rain and Storm Timing
6 AM–noon: Mainly dry. Patchy fog possible west.
Noon–3 PM: Isolated storms begin developing near Western Maryland/higher terrain.
3–6 PM: Scattered storm development possible across western, north-central and central Maryland.
6–9 PM: Isolated/scattered storms possible farther east, including Baltimore, Washington, Southern Maryland and the Eastern Shore.
After 9 PM: Coverage gradually decreases.
Severe Weather
The severe-weather risk is Marginal, meaning isolated severe thunderstorms are possible rather than a widespread outbreak.
Damaging wind is the principal threat.
NWS Baltimore/Washington expects stronger wind shear Saturday than Friday—around 30–35 knots—but somewhat lower instability and fewer storms overall. If a storm organizes successfully, it could produce a significant downburst.
Flooding
Atmospheric moisture decreases slightly compared with Friday, but storms will still be capable of heavy rainfall.
Localized flash flooding is possible where storms repeatedly cross the same location.
Northern and northeastern Maryland may remain somewhat more vulnerable after locally heavy rainfall Friday.
NWS Mount Holly places its Maryland portion within a Marginal Risk for excessive rainfall Saturday.
Wind
Outside thunderstorms, winds remain generally light from the south or southwest.
Gusts can rapidly increase near thunderstorms.
Fog
Patchy fog may develop Saturday morning across Western Maryland valleys and any locations that received significant rainfall Friday evening.
Fog should improve after sunrise.
Chesapeake Bay and Tidal Potomac
South to southwest flow continues.
NWS Baltimore/Washington indicates Small Craft Advisory conditions may again become possible Saturday afternoon/evening because of southerly channeling.
Thunderstorms could produce locally damaging winds and frequent lightning over the waters.
Coastal Flooding
Tidal anomalies are expected to increase through the weekend in response to continued southerly flow.
Periods of minor coastal flooding may become possible at sensitive locations near times of high tide.
Heat and Humidity
Saturday remains very humid.
Heat indices east of the Blue Ridge are expected to approach 100°.
No Maryland Heat Advisory was listed in the current LWX, PHI or AKQ discussions as of Friday afternoon.
Air Quality
No verified statewide Maryland air-quality alert was identified in the current official guidance retrieved for this package.
Humidity may contribute to hazy-looking skies, but visual haze alone does not establish unhealthy particle pollution. Air quality can also vary substantially by location.
Winter Weather
There are no winter-weather concerns.
Active Watches, Warnings and Advisories
The Severe Thunderstorm Watch in effect Friday evening expires at 9 PM and is therefore not a Saturday hazard unless a new product is issued.
As of the Friday afternoon NWS discussions:
- LWX listed no standing Maryland land advisory beyond the convective watch product.
- PHI listed no Maryland Heat Advisory.
- AKQ listed no Maryland watch, warning or advisory.
- Small Craft Advisory conditions may redevelop on portions of the Chesapeake Bay Saturday afternoon/evening.
Looking Ahead
Sunday currently appears to offer a relative break from widespread thunderstorms.
Hot and humid conditions continue, with highs generally in the upper 80s and lower 90s.
Sunday through Tuesday may be the hottest portion of the stretch. Thunderstorm chances increase again later next week as additional disturbances and eventually a possible cold front approach.