Dense Fog, Charles
- When
- May 27, 6:40 AM EST to 7:45 AM EST
- Where
- Charles forecast zone
- Reported by
- AWOS
- Coordinates
- 38.474, -77.013 (the zone’s center; the record gives no point)
Visibility was around one-quarter mile.
Dense Fog in Maryland, May 27, 2020
An influx of low level moisture off the Atlantic and Chesapeake Bay became trapped underneath a subsidence inversion. When coupled with calm winds in a weak surface ridge and cool water temp on Chesapeake Bay, widespread dense fog formed across portions of southern Maryland.
Where it happened
Every event with a place to put it; 3 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 3
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
What happened
The episode as NWS LWX wrote it up.
An influx of low level moisture off the Atlantic and Chesapeake Bay became trapped underneath a subsidence inversion. When coupled with calm winds in a weak surface ridge and cool water temp on Chesapeake Bay, widespread dense fog formed across portions of southern Maryland.
The radar
The national radar mosaic for the moment the first event began.
Event by event
3 dense fog. Local standard time, as filed.
Dense Fog, St. Mary'S
- When
- May 27, 6:40 AM EST to 9:00 AM EST
- Where
- St. Mary'S forecast zone
- Reported by
- AWOS
- Coordinates
- 38.216, -76.529 (the zone’s center; the record gives no point)
Visibility was around one-quarter mile.
Dense Fog, Calvert
- When
- May 27, 6:40 AM EST to 9:00 AM EST
- Where
- Calvert forecast zone
- Reported by
- AWOS
- Coordinates
- 38.535, -76.531 (the zone’s center; the record gives no point)
Visibility was around one-quarter mile.
What these are
- Dense Fog
- Fog reducing visibility to a quarter mile or less, filed where it caused accidents or disruption.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Excessive Heat in Arizona, May 27 to 31, 2020
- Flash Flood and Hail in Texas, May 27, 2020
- Damaging Wind and Lightning Strike in Texas, May 27 to 28, 2020
- Lightning Strike in Florida, May 27, 2020
- Rip Current in California, May 27, 2020
- Tornadoes and Hail in Texas, May 27, 2020
- Hail and Damaging Winds in Texas, May 27 to 28, 2020
- Hail and Damaging Wind in Texas, May 27, 2020
- Tornado in North Carolina, May 27, 2020
- Heat and Damaging Winds in Vermont, May 27, 2020
- Damaging Winds in New York, May 27, 2020
- Flash Flood in New Hampshire, May 27, 2020
More
Every storm in Maryland in 2020Every state in 2020This day in weather historyWarnings in Maryland, May 2020
Sources
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-30. Each event’s entry at NCEI: 893870, 893872, 893873.