import numpy as np

def denormalize_and_split(pred: np.ndarray, out_stats: dict):
    # pred: (1,27,4,300,300) or (27,4,300,300)
    if pred.ndim == 5:
        pred = pred[0]
    mean = out_stats["mean"][:, :, None, None]  # (27,4,1,1)
    std  = out_stats["std"][:, :, None, None]
    pred = pred * std + mean                    # (27,4,300,300)

    u = pred[:, 0]
    v = pred[:, 1]
    w = pred[:, 2]
    k = pred[:, 3]
    return u, v, w, k