def _shift_weather_features_back(weather_report, hours):
    """
    Shift weather observations back in time. The weather observation at time t can
    then be interpreted as a forecast made at time t. A number of hours equal to the
    shift are rolled off the end of the DataFrame.
    """
    shifted = weather_report.copy()
    shifted.wind_speed = shifted.wind_speed.shift(-hours)
    shifted.temperature = shifted.temperature.shift(-hours)
    shifted.cloud_cover = shifted.cloud_cover.shift(-hours)
    shifted.pressure = shifted.pressure.shift(-hours)
    shifted = shifted[:-hours]
    return shifted