weather prediction thing

--spring + summer

forecast = {
    'sunny',
    'partly cloudy',
    'mostly cloudy',
    'overcast',
    'sunny',
    'light rain',
    'rain',
    'heavy rain with a chance of lightning'
}

while true do
    clouds = math.random(4)
    precip = math.random(2)
    temp = math.random(70,90)

    cmd = io.read()
    if cmd == 'exit' then
        break
    end

    local v = clouds*precip

    temp = temp + ((v-4<0) and math.random((v-4)*3,0) or math.random(0,(v-4)*3))

    print(
        "Today's weather will be " ..
        forecast[v] ..
        " with a temperature of " ..
        temp ..
        "."
    )
end