Dense Fog, Rock
- When
- September 12, 2:00 AM CST to 7:00 AM CST
- Where
- Rock forecast zone
- Reported by
- ASOS
- Coordinates
- 42.671, -89.072 (the zone’s center; the record gives no point)
Dense Fog in Wisconsin, September 12, 2009
The combination of high pressure over the Great Lakes Region, light winds, clear skies, and a moist layer of air near the ground allowed for the development of dense fog overnight. Newspaper articles indicated that there were a few vehicle accidents, and there were some delays in aircraft departures at some airports.
Where it happened
Every event with a place to put it; 4 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
- 4
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 MKX wrote it up.
The combination of high pressure over the Great Lakes Region, light winds, clear skies, and a moist layer of air near the ground allowed for the development of dense fog overnight. Newspaper articles indicated that there were a few vehicle accidents, and there were some delays in aircraft departures at some airports. Visibilities were reduced to 1/8 to 1/4 mile.
The radar
The national radar mosaic for the moment the first event began.
Event by event
4 dense fog. Local standard time, as filed.
Dense Fog, Walworth
- When
- September 12, 2:00 AM CST to 7:00 AM CST
- Where
- Walworth forecast zone
- Reported by
- ASOS
- Coordinates
- 42.669, -88.542 (the zone’s center; the record gives no point)
Dense Fog, Racine
- When
- September 12, 2:00 AM CST to 7:00 AM CST
- Where
- Racine forecast zone
- Reported by
- ASOS
- Coordinates
- 42.730, -87.812 (the zone’s center; the record gives no point)
Dense Fog, Kenosha
- When
- September 12, 2:00 AM CST to 7:00 AM CST
- Where
- Kenosha forecast zone
- Reported by
- ASOS
- Coordinates
- 42.573, -87.840 (the zone’s center; the record gives no point)
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
- Lightning Strikes in California, September 12, 2009
- Flash Flood and Lightning Strike in Massachusetts, September 12, 2009
- Flooding in Kansas, September 12 to 13, 2009
- Dense Fog in Wisconsin, September 12 to 13, 2009
- Waterspouts in Gulf of Mexico, September 12, 2009
- Flash Flood and Heavy Rain in Arizona, September 12, 2009
- Debris Flow in Puerto Rico, September 12, 2009
- Funnel Cloud in Iowa, September 12, 2009
- Flash Flood in Arizona, September 12, 2009
- Heavy Rain in Florida, September 12, 2009
More
Every storm in Wisconsin in 2009Every state in 2009This day in weather historyWarnings in Wisconsin, September 2009
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 2026-10-01. Each event’s entry at NCEI: 196739, 196740, 196741, 196742.