Fallout Weather Upper-air winds, read for fallout

Educational tool. Not an emergency alert system or official guidance. In an emergency, follow instructions from authorities.

Where would today's winds carry fallout near Milwaukee, Wisconsin?

The map below estimates where today's forecast upper-air winds would carry fallout from each potential target near Milwaukee, and whether any of it could reach the city.

Milwaukee is itself on this site's list of potential targets. Close to an explosion, blast and heat are the main dangers, and fallout would begin within minutes whatever the wind.

There are 8 other listed targets in range of Milwaukee. The nearest is Chicago, about 81 miles to the south.

Winds high above the continental United States blow from the west more often than not, so targets to the west of Milwaukee are upwind most often: Minneapolis. On any given day the pattern can be quite different, which is what the map below shows.

Listed targets in range of Milwaukee (illustrative, not a prediction)
Potential targetTypeFrom Milwaukee
Milwaukee, WIMetro areaHere
Chicago, ILMetro area81 mi south
Indianapolis, INMetro area243 mi south-southeast
Detroit, MIMetro area252 mi east
Minneapolis, MNMetro area298 mi west-northwest
Wright-Patterson AFB / Dayton, OHMilitary site299 mi southeast
Cincinnati, OHMetro area324 mi southeast
St. Louis, MOMetro area328 mi south-southwest
Columbus, OHMetro area331 mi southeast

Many factors affect where fallout travels and how dangerous it is. This educational tool takes only three into account: the forecast winds from the ground up to the top of the mushroom cloud, an assumed weapon size, and an assumed burst type (on the ground or in the air). The target list is illustrative, not a prediction. How to read the map.

Official preparedness guidance

This is a summary of public guidance from Ready.gov and the CDC. It does not come from this map, and the map should not be used to make emergency decisions.

  1. Get inside. Official guidance is to get into the nearest solid building, as deep and central as possible: a basement, or the middle of a large building.
  2. Stay inside. Official guidance is to stay sheltered for at least 24 hours unless authorities say otherwise, because fallout radiation is strongest in the first hours and decays quickly.
  3. Stay tuned. Follow official instructions, for example by battery-powered or hand-crank radio.

Read the sources: Ready.gov: Radiation Emergencies and CDC: Radiation Emergencies. Our fuller summary lists each source.