Maryland, 2013

Dense Fog in Maryland, May 9, 2013

May 9, 2013 · NWS LWX · 3 events in 3 counties and zones

Heavy rain occurred during the day as low pressure moved north of the Mid Atlantic. Low level moisture was in place and breaks in the cloud cover led to fog development overnight.

Where it happened

Every event with a place to put it; 1 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

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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.

Heavy rain occurred during the day as low pressure moved north of the Mid Atlantic. Low level moisture was in place and breaks in the cloud cover led to fog development overnight.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Baltimore/Washington wrote its last area forecast discussion before the first event at May 8, 10:32 PM EST, 2 hours 23 minutes earlier.

Area forecast discussion, May 8, 10:32 PM EST, 2 hours 23 minutes before
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Hazardous weather outlook, May 8, 10:38 PM EST, 2 hours 17 minutes before
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The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

3 dense fog. Local standard time, as filed.

Dense Fog, Montgomery

When
May 9, 12:55 AM EST to 2:00 AM EST
Where
Montgomery forecast zone
Reported by
AWOS

Visibilities of a quarter mile were measured at Gaithersburg Airport.

Dense Fog, Howard

When
May 9, 12:55 AM EST to 2:55 AM EST
Where
Howard forecast zone
Reported by
AWOS

Visibilities of a quarter mile were estimated at Gaithersburg Airport.

Dense Fog, Frederick

When
May 9, 5:20 AM EST to 7:15 AM EST
Where
Frederick forecast zone
Reported by
AWOS
Coordinates
39.472, -77.398 (the zone’s center; the record gives no point)

Visibilities of a quarter mile were measured at Frederick Airport.

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

More

Every storm in Maryland in 2013Every state in 2013This day in weather historyWarnings in Maryland, May 2013

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 2026-09-24. Each event’s entry at NCEI: 456135, 456136, 456134.