FalloutCast

Weather-driven fallout planning estimate

Units

Latitude Longitude

Find a place, address, or ZIP

Click the map to set ground zero, type coordinates, or search a place / address / ZIP. Starts on Cheyenne, Wyoming — next to the F.E. Warren ICBM field, so the default view has something to look at.

Model detail Fast planning model (Tier 0 · WSEG-10) Layered live-wind model (Tier 1 · multi-layer)

What do these mean?

The fast planning model is WSEG-10, a documented analytic fallout-planning model (Hanifen 1980): it collapses the atmosphere into one effective wind plus a shear term, so it computes instantly. The layered model advects each altitude slice of the cloud with the live wind at that height, so the plume can curve where winds change with altitude. It needs a live vertical wind profile.

Wind Manual override (skips the live wind fetch)

Uncertainty band Ensemble band (real GFS ensemble winds)

Yield (Mt)

Fission fraction

What is fission fraction?

The share of the total yield that comes from fission (the rest is fusion). Fallout radioactivity comes from fission products, so the modeled dose rates scale with this fraction.