def is_stat(tmp):
    """
    Check if the string is a station.

    Parameters
    ----------
    tmp : str
        String to check.

    Returns
    -------
    station : str
        station identified.

    """
    station = ''
    stationlist = ['SNA', 'BEW', 'SNA', 'BEW', 'BPI', 'BFT', 'BLE', 'BLF',
        'BOSA', 'BFS', 'CVN', 'CER', 'ERS', 'FRS', 'GRM', 'HVD', 'KSR',
        'KSD', 'MSN', 'NWL', 'PRY', 'PHA', 'POF', 'POG', 'PKA', 'SLR',
        'SEK', 'SOE', 'SBO', 'SUR', 'SWZ', 'UPI', 'WIN', 'KTS', 'KT1',
        'KT2', 'KT3', 'KIM', 'TUH', 'CAV', 'BUL', 'BOS', 'SME', 'CAV',
        'NCA', 'SPB', 'JOZ', 'EVA', 'KIM', 'VIR', 'BPI', 'UMT', 'ZOM',
        'LLO', 'MZU', 'VPT', 'CGY', 'PRE', 'MDN', 'MDL', 'PSD', 'QUA']
    for i in stationlist:
        if tmp.find(i) > -1:
            station = i
    if station == '':
        tmp2 = tmp.replace('P', 'F')
        for i in stationlist:
            if tmp2.find(i) > -1:
                station = i
    return station
