Operational Data Checking

An automatic data checking system has been implemented at ECMWF to trigger warnings in case of anomalies affecting the quality or the availability of the data assimilated by the model. Selected statistical parameters (number of observations, bias correction, and mean bias-corrected background, analysis departures and probability of gross error) are checked against an expected range. An appropriate alert message (including a time series plot) is generated if statistics are outside the specified ranges. A severity level (slight, considerable, severe) is assigned to each message depending on how far statistics are from the expected values. Two kinds of ranges are used by the automatic checking: Soft and Hard limits. Soft limits are updated automatically using statistics from the last twenty days (extremes are excluded during this process). Hard limits are adjusted manually when required.

Currently, the automatic checking is limited to data passing through the minimisation process (including VarBC passive data). It's being applied twice a day to the delayed cut-off 4D-VAR cycles (00 and 12) and four times a day to the early delivery assimilation system (00,06,12 and 18).

The alarm system results are based on feedback information from the ECMWF data assimilation and consequently reflect the ECMWF data usage. Although most warnings are related to data problems, they may on occasion also be related to model issues. Alerts are provided for information on an as-is basis and may be withdrawn or changed without notice. ECMWF accepts no responsibility for actions taken on the basis of these results.

Delayed cut-off 4DVAR at 2022-11-12 12:00

AMSUA Pacific RARS
All NOAA-18 AMSUA ALL SKY CHANNELS Global : all data missing
Severely_persistent: obs_number=0, expected range: 359.87 1681.12
All NOAA-19 AMSUA ALL SKY CHANNELS Global : all data missing
Severely_persistent: obs_number=0, expected range: 114.61 1466.89
airs
AQUA AIRS RADIANCES CHANNEL 791 : out of range
Considerable: stdev_fgdepar=0.3208, expected range: 0.2084 0.2769
gpsro
All KOMPSAT-5 GPSRO SETTING ALL HEIGHTS Global : all data missing
Severe: obs_number=0, expected range: 172.53 898.22
SPIRE LEMUR 3U GPSRO RISING HEIGHT 6-8 KM : out of range
Severe: stdev_norm_fgdepar=0.3384, expected range: 0.1266 0.2213
SENTINEL 6A GPSRO SETTING (7 impact heights affected) : out of range
Considerable: obs_number=1339.0000, expected range: 2184.3679 2951.2792
Atmospheric Motion Vector
HIMAWARI-8 AMV VIS1 WIND VECTOR DIFF (M/S) (2 pressure layers affected : out of range
7 times in the last 10 days for at least one item
Severely_persistent: obs_number=783.0000, expected range: 504.0657 534.9113
METEOSAT-9 AMV VIS2 WIND VECTOR DIFF (M/S) PRESSURE LAYER 900-1200 (HP : out of range
Considerable: obs_number=1094.0000, expected range: 727.8457 851.8023
resat
All NOAA-19 SBUV ALL LAYERS Global : all data missing
Severely_persistent: obs_number=0, expected range: 512.70 557.77
Radiosondes
LAND TEMP Q (G/KG) 26781 PRESSURE LAYER 600-900 (HPA) : out of range
Severe: rms_fgdepar=2.1101, expected range: 0.0000 1.1115
LAND TEMP Q (G/KG) 40417 PRESSURE LAYER 900-1200 (HPA) : out of range
Severe: rms_fgdepar=6.1867, expected range: 0.0000 5.3205
LAND TEMP Q (G/KG) 83899 PRESSURE LAYER 900-1200 (HPA) : out of range
Severe: rms_fgdepar=2.8558, expected range: 0.0000 1.1394
LAND TEMP TEMPERATURE (K) 44373 PRESSURE LAYER 0-300 (HPA) : out of range
Severe: rms_fgdepar=7.9614, expected range: 0.0000 4.1052
HIGH RESO LAND TEMP Q (G/KG) 57749 PRESSURE LAYER 900-1200 (HPA) : out of range
Severe: rms_fgdepar=2.3365, expected range: 0.0000 1.1894
HIGH RESO LAND TEMP Q (G/KG) 87418 PRESSURE LAYER 900-1200 (HPA) : out of range
Severe: rms_fgdepar=2.2376, expected range: 0.0000 0.7511
HIGH RESO LAND TEMP Q (G/KG) 94672 PRESSURE LAYER 900-1200 (HPA) : out of range
Severe: rms_fgdepar=2.4000, expected range: 0.0000 1.2556
amdar
AMDAR WIND VECTOR DIFF (M/S) AEA046 PRESSURE LAYER 0-300 (HPA) : out of range
3 times in the last 10 days for at least one item
Severe: avg_fgdepar=20.7194, expected range: -23.4790 38.9163
Severe: rms_fgdepar=20.7194, expected range: 0.0000 41.2914
WIGOS AMDAR TEMPERATURE (K) CNSPPT PRESSURE LAYER 300-600 (HPA) : out of range
2 times in the last 10 days for at least one item
Severe: avg_pge=0.8665, expected range: 0.4002 0.7500
WIGOS AMDAR TEMPERATURE (K) CNSQPM PRESSURE LAYER 300-600 (HPA) : out of range
Severe: avg_fgdepar=-9.1536, expected range: -21.5034 8.2483
Severe: rms_fgdepar=9.4395, expected range: 0.0000 22.0824
Severe: avg_pge=0.8737, expected range: -0.1488 0.7500
WIGOS AMDAR TEMPERATURE (K) CNNKXR PRESSURE LAYER 600-900 (HPA) : out of range
Severe: avg_fgdepar=-9.0282, expected range: -43.5040 22.6912
Severe: rms_fgdepar=11.1206, expected range: 0.0000 41.0429
WIGOS AMDAR TEMPERATURE (K) CNQNOP PRESSURE LAYER 600-900 (HPA) : out of range
Severe: avg_fgdepar=-11.2720, expected range: -40.3321 18.8117
Severe: rms_fgdepar=11.2720, expected range: 0.0000 40.4255
Severe: avg_pge=0.8759, expected range: -0.2066 0.7500
WIGOS AMDAR WIND VECTOR DIFF (M/S) V1NMX0ZA PRESSURE LAYER 900-1200 (H : out of range
Severe: rms_fgdepar=15.7036, expected range: 0.0000 5.8008
ADS-C WIND VECTOR DIFF (M/S) 5B5F5EBA PRESSURE LAYER 0-300 (HPA) : out of range
Severe: rms_fgdepar=21.5614, expected range: 0.0000 23.5582
ADS-C WIND VECTOR DIFF (M/S) CXFMHCBA PRESSURE LAYER 0-300 (HPA) : out of range
Severe: rms_fgdepar=17.4755, expected range: 0.0000 8.7958
ADS-C WIND VECTOR DIFF (M/S) EGUJ4NZA PRESSURE LAYER 0-300 (HPA) : out of range
3 times in the last 10 days for at least one item
Severe: rms_fgdepar=27.4815, expected range: -56.2672 74.7919
ADS-C WIND VECTOR DIFF (M/S) FNQX4QZA PRESSURE LAYER 0-300 (HPA) : out of range
1 times in the last 10 days for at least one item
Severe: avg_fgdepar=37.7116, expected range: -4.2957 12.6479
Severe: rms_fgdepar=43.0646, expected range: 0.0000 29.7448
ADS-C WIND VECTOR DIFF (M/S) GOKY1LZA PRESSURE LAYER 0-300 (HPA) : out of range
1 times in the last 10 days for at least one item
Severe: rms_fgdepar=23.2509, expected range: 0.0000 11.0096
ADS-C WIND VECTOR DIFF (M/S) GURICNJA PRESSURE LAYER 0-300 (HPA) : out of range
Severe: rms_fgdepar=16.9827, expected range: 0.0000 9.6610
ADS-C WIND VECTOR DIFF (M/S) QN3FJZBA PRESSURE LAYER 0-300 (HPA) : out of range
Severe: rms_fgdepar=28.1315, expected range: 0.0000 23.8532
ADS-C WIND VECTOR DIFF (M/S) RCKUIJZA PRESSURE LAYER 0-300 (HPA) : out of range
Severe: rms_fgdepar=20.0872, expected range: 0.0000 11.8529
ADS-C WIND VECTOR DIFF (M/S) S5TJ0KRA PRESSURE LAYER 0-300 (HPA) : out of range
Severe: rms_fgdepar=20.7999, expected range: 0.0000 8.0400
ADS-C WIND VECTOR DIFF (M/S) VE500QRA PRESSURE LAYER 0-300 (HPA) : out of range
Severe: rms_fgdepar=24.5682, expected range: 0.0000 10.8996
airep
AIREP WIND VECTOR DIFF (M/S) AAL151 PRESSURE LAYER 0-300 (HPA) : out of range
2 times in the last 10 days for at least one item
Severe: avg_fgdepar=22.2503, expected range: -1.9399 11.0881
Severe: rms_fgdepar=30.0422, expected range: 0.0000 22.5289
AIREP WIND VECTOR DIFF (M/S) AAL49 PRESSURE LAYER 0-300 (HPA) : out of range
1 times in the last 10 days for at least one item
Severe: avg_fgdepar=23.3699, expected range: -1.2752 10.5887
Severe: rms_fgdepar=30.4480, expected range: 0.0000 15.7308
AIREP WIND VECTOR DIFF (M/S) ACA859 PRESSURE LAYER 0-300 (HPA) : out of range
2 times in the last 10 days for at least one item
Severe: avg_fgdepar=30.0354, expected range: -5.2023 13.0791
Severe: rms_fgdepar=39.0564, expected range: 0.0000 24.9660
AIREP WIND VECTOR DIFF (M/S) ACA860 PRESSURE LAYER 0-300 (HPA) : out of range
Severe: avg_fgdepar=53.7743, expected range: -2.8386 9.8089
Severe: rms_fgdepar=53.7743, expected range: 0.0000 11.5313
AIREP WIND VECTOR DIFF (M/S) AFR694 PRESSURE LAYER 0-300 (HPA) : out of range
1 times in the last 10 days for at least one item
Severe: avg_fgdepar=20.2745, expected range: 0.4644 5.7783
Severe: rms_fgdepar=34.2140, expected range: 0.2079 7.1397
AIREP WIND VECTOR DIFF (M/S) BAW26E PRESSURE LAYER 0-300 (HPA) : out of range
Severe: rms_fgdepar=25.7127, expected range: 0.0000 15.0391
AIREP WIND VECTOR DIFF (M/S) KLM685 PRESSURE LAYER 0-300 (HPA) : out of range
1 times in the last 10 days for at least one item
Severe: avg_fgdepar=23.4447, expected range: 0.3561 7.4092
Severe: rms_fgdepar=34.9692, expected range: 0.0968 9.5295
AIREP WIND VECTOR DIFF (M/S) LOT2LY PRESSURE LAYER 0-300 (HPA) : out of range
1 times in the last 10 days for at least one item
Severe: rms_fgdepar=25.6571, expected range: 0.0000 23.1705
AIREP WIND VECTOR DIFF (M/S) UAL26 PRESSURE LAYER 0-300 (HPA) : out of range
Severe: avg_fgdepar=28.9714, expected range: -26.2391 39.4311
Severe: rms_fgdepar=38.8602, expected range: 0.0000 50.2033
AIREP WIND VECTOR DIFF (M/S) UAL760 PRESSURE LAYER 0-300 (HPA) : out of range
Severe: avg_fgdepar=20.4995, expected range: -0.3497 6.2550
Severe: rms_fgdepar=26.7007, expected range: 0.0000 7.2689
AIREP WIND VECTOR DIFF (M/S) UAL973 PRESSURE LAYER 0-300 (HPA) : out of range
Severe: rms_fgdepar=33.6194, expected range: 0.0000 15.8457
AIREP WIND VECTOR DIFF (M/S) VIR155M PRESSURE LAYER 0-300 (HPA) : out of range
Severe: rms_fgdepar=20.7908, expected range: 0.0000 19.2740
prof
EUROPEAN WIND PROFILER VECTOR DIFF (M/S) 01498 PRESSURE LAYER 600-900 : out of range
4 times in the last 10 days for at least one item
Severe: rms_fgdepar=15.0184, expected range: 0.0000 8.9194
Severe: avg_pge=0.8494, expected range: -0.3829 0.7500
EUROPEAN WIND PROFILER VECTOR DIFF (M/S) 02918 PRESSURE LAYER 600-900 : out of range
1 times in the last 10 days for at least one item
Severe: rms_fgdepar=15.4828, expected range: 0.0000 6.4590
Severe: avg_pge=0.8542, expected range: -0.6731 0.7500
EUROPEAN WIND PROFILER VECTOR DIFF (M/S) 02954 PRESSURE LAYER 600-900 : out of range
1 times in the last 10 days for at least one item
Severe: avg_fgdepar=20.9458, expected range: -1.3033 5.6088
Severe: rms_fgdepar=21.5333, expected range: 0.0000 7.3634
Severe: avg_pge=0.9098, expected range: -0.2727 0.4574
EUROPEAN WIND PROFILER VECTOR DIFF (M/S) 02995 (2 pressure layers affe : out of range
Severe: rms_fgdepar=15.1456, expected range: 0.9777 2.7430
Severe: avg_pge=0.8600, expected range: -0.1052 0.1840
EUROPEAN WIND PROFILER VECTOR DIFF (M/S) 02925 PRESSURE LAYER 900-1200 : out of range
Severe: rms_fgdepar=18.8930, expected range: 0.4321 5.6344
Severe: avg_pge=0.9129, expected range: -0.4440 0.7500
EUROPEAN WIND PROFILER VECTOR DIFF (M/S) 02995 PRESSURE LAYER 900-1200 : out of range
Severe: avg_fgdepar=23.4977, expected range: -1.6527 5.7960
EUROPEAN WIND PROFILER VECTOR DIFF (M/S) 94926 PRESSURE LAYER 900-1200 : out of range
Severe: avg_fgdepar=20.9341, expected range: -0.9207 7.1993
Severe: rms_fgdepar=20.9341, expected range: 0.0000 8.0942
Severe: avg_pge=0.9244, expected range: -0.2999 0.7500
synop
AUTOMATIC LAND SYNOP SURFACE PRESSURE (PA) 68296 : out of range
5 times in the last 10 days for at least one item
Severely_persistent: avg_pge=0.8400, expected range: -1.3128 0.7500
BUFR LAND SYNOP SURFACE PRESSURE (PA) 81797 : out of range
22 times in the last 10 days for at least one item
Severely_persistent: avg_fgdepar=591.5291, expected range: 470.4139 730.1714
Severely_persistent: rms_fgdepar=592.1133, expected range: 472.9706 728.7794
AUTOMATIC LAND SYNOP SURFACE PRESSURE (PA) 10007 : out of range
1 times in the last 10 days for at least one item
Severe: avg_pge=0.8908, expected range: -1.7934 0.7500
MANUAL LAND SYNOP SURFACE PRESSURE (PA) 40660 : out of range
Severe: avg_fgdepar=-978.4926, expected range: -147.3879 194.2762
Severe: rms_fgdepar=978.4926, expected range: 0.0000 136.3159
Severe: avg_pge=0.9405, expected range: -1.4027 0.7500
MANUAL LAND SYNOP SURFACE PRESSURE (PA) 47075 : out of range
1 times in the last 10 days for at least one item
Severe: rms_fgdepar=398.8838, expected range: 0.0000 169.9932
Severe: avg_pge=0.8500, expected range: -0.2421 0.3904
MANUAL LAND SYNOP SURFACE PRESSURE (PA) 82596 : out of range
Severe: avg_pge=0.8313, expected range: -0.8523 0.7500
MANUAL LAND SYNOP SURFACE PRESSURE (PA) 82983 : out of range
Severe: avg_fgdepar=560.7440, expected range: -195.9624 225.2050
Severe: rms_fgdepar=813.3150, expected range: 0.0000 204.5742
MANUAL LAND SYNOP SURFACE PRESSURE (PA) 83332 : out of range
Severe: rms_fgdepar=351.2377, expected range: 0.0000 138.8055
MANUAL LAND SYNOP RH2M (%) 42473 : out of range
Severe: avg_pge=0.9979, expected range: -0.4108 0.6645
MANUAL LAND SYNOP RH2M (%) 42770 : out of range
1 times in the last 10 days for at least one item
Severe: avg_pge=0.9496, expected range: -1.1817 0.7500
MANUAL LAND SYNOP RH2M (%) 42915 : out of range
4 times in the last 10 days for at least one item
Severe: avg_pge=0.9999, expected range: -1.5334 0.7500
MANUAL LAND SYNOP RH2M (%) 60770 : out of range
Severe: rms_fgdepar=34.2507, expected range: 0.0000 9.8924
MANUAL LAND SYNOP RH2M (%) 61731 : out of range
Severe: avg_pge=0.9925, expected range: -0.6985 0.7500
MANUAL LAND SYNOP RH2M (%) 64706 : out of range
2 times in the last 10 days for at least one item
Severe: rms_fgdepar=41.8086, expected range: 0.0000 41.1020
Severe: avg_pge=0.9899, expected range: -0.4450 0.5228
BUFR LAND SYNOP SURFACE PRESSURE (PA) 10007 : out of range
2 times in the last 10 days for at least one item
Severe: avg_pge=0.9013, expected range: -1.6020 0.7500
BUFR LAND SYNOP SURFACE PRESSURE (PA) 30957 : out of range
Severe: rms_fgdepar=384.8248, expected range: 0.0000 119.3583
BUFR LAND SYNOP SURFACE PRESSURE (PA) 84825 : out of range
Severe: avg_fgdepar=-549.7196, expected range: -717.4337 -336.5818
Severe: rms_fgdepar=550.1698, expected range: 351.3853 707.3838
BUFR LAND SYNOP RH2M (%) 14308 : out of range
Severe: rms_fgdepar=48.5944, expected range: 0.0000 24.2468
BUFR LAND SYNOP RH2M (%) 42459 : out of range
4 times in the last 10 days for at least one item
Severe: avg_pge=0.9996, expected range: -1.2581 0.7500
ship
BUFR SHIP SYNOP SURFACE PRESSURE (PA) C6DP7 : out of range
11 times in the last 10 days for at least one item
Severely_persistent: avg_fgdepar=545.5448, expected range: 17.7668 834.2461
Severely_persistent: rms_fgdepar=545.5448, expected range: 17.5591 836.3917
BUFR SHIP SYNOP SURFACE PRESSURE (PA) WYQ4356 : out of range
11 times in the last 10 days for at least one item
Severely_persistent: avg_fgdepar=-602.3284, expected range: -2005.5936 2421.0657
Severely_persistent: rms_fgdepar=605.9606, expected range: -1806.1358 2371.9145
Severely_persistent: avg_pge=0.8553, expected range: -1.3202 0.7500
BUFR SHIP SYNOP WIND VECTOR DIFF (M/S) JPTX : out of range
15 times in the last 10 days for at least one item
Severely_persistent: avg_fgdepar=21.3756, expected range: -20.5786 41.6254
Severely_persistent: rms_fgdepar=21.3756, expected range: 0.0000 41.6032
BUFR SHIP SYNOP SURFACE PRESSURE (PA) 2AKI4 : out of range
1 times in the last 10 days for at least one item
Severe: avg_fgdepar=764.3925, expected range: -185.7288 117.4978
Severe: rms_fgdepar=764.3925, expected range: 0.0000 175.7132
Severe: avg_pge=0.8604, expected range: -1.2564 0.7500
BUFR SHIP SYNOP SURFACE PRESSURE (PA) 2IYH4 : out of range
Severe: avg_fgdepar=994.7462, expected range: -552.9419 932.8270
Severe: rms_fgdepar=994.7462, expected range: 0.0000 800.9513
Severe: avg_pge=0.8951, expected range: -1.0504 0.7500
BUFR SHIP SYNOP SURFACE PRESSURE (PA) 3E3566 : out of range
Severe: avg_fgdepar=581.0948, expected range: -69.3932 577.8332
Severe: rms_fgdepar=581.0948, expected range: 0.0000 578.4974
Severe: avg_pge=0.8225, expected range: -0.1047 0.7500
BUFR SHIP SYNOP SURFACE PRESSURE (PA) 3FJB3 : out of range
Severe: rms_fgdepar=373.8054, expected range: 0.0000 206.3007
BUFR SHIP SYNOP SURFACE PRESSURE (PA) 7JWH : out of range
3 times in the last 10 days for at least one item
Severe: avg_fgdepar=510.4235, expected range: -121.6656 92.3358
Severe: rms_fgdepar=510.9084, expected range: 0.0000 114.9854
BUFR SHIP SYNOP SURFACE PRESSURE (PA) LAON8 : out of range
2 times in the last 10 days for at least one item
Severe: rms_fgdepar=371.0286, expected range: 0.0000 277.4009
Severe: avg_pge=0.8648, expected range: -0.6710 0.7500
BUFR SHIP SYNOP SURFACE PRESSURE (PA) VRZQ9 : out of range
Severe: avg_fgdepar=513.7124, expected range: -386.2398 401.5586
Severe: rms_fgdepar=513.7124, expected range: 0.0000 387.8091
buoy
DRIFTING BUOYS SURFACE PRESSURE (PA) 3301615 : out of range
9 times in the last 10 days for at least one item
Severely_persistent: avg_fgdepar=536.5880, expected range: -816.0116 894.3397
Severely_persistent: rms_fgdepar=576.6288, expected range: -755.1851 971.4018
Severely_persistent: avg_pge=0.8340, expected range: -1.2605 0.7500
DRIFTING BUOYS SURFACE PRESSURE (PA) 6204562 : out of range
3 times in the last 10 days for at least one item
Severe: rms_fgdepar=351.2493, expected range: 0.0000 145.5027
snow
BUFR LAND SYNOP SNOW (CM) _MF1EB15 : out of range
38 times in the last 10 days for at least one item
Severely_persistent: avg_fgdepar=-790.6785, expected range: -806.6906 -756.0481
Severely_persistent: rms_fgdepar=790.6787, expected range: 756.3374 806.5168
BUFR LAND SYNOP SNOW (CM) _MI17AC6 : out of range
16 times in the last 10 days for at least one item
Severely_persistent: avg_fgdepar=-64.6305, expected range: -64.8682 -24.2934
Severely_persistent: rms_fgdepar=64.6655, expected range: 24.3905 64.8771
BUFR LAND SYNOP SNOW (CM) : out of range
Slight: avg_fgdepar=-28.2095, expected range: -50.9996 -32.9164
t2m
METAR 2M TEMPERATURE (K) KTLH : out of range
18 times in the last 10 days for at least one item
Severely_persistent: avg_fgdepar=-15.7483, expected range: -18.9933 -4.6583
Severely_persistent: rms_fgdepar=15.7483, expected range: 5.2753 19.4925
BUFR LAND SYNOP 2M TEMPERATURE (K) _MI13149 : out of range
6 times in the last 10 days for at least one item
Severely_persistent: avg_fgdepar=-12.3531, expected range: -15.0022 -6.6371
Severely_persistent: rms_fgdepar=12.3695, expected range: 6.6477 15.1553
BUFR LAND SYNOP 2M TEMPERATURE (K) _MI1D122 : out of range
17 times in the last 10 days for at least one item
Severely_persistent: rms_fgdepar=12.0467, expected range: 6.0725 17.2378
BUFR LAND SYNOP 2M TEMPERATURE (K) _MI1D581 : out of range
22 times in the last 10 days for at least one item
Severely_persistent: avg_fgdepar=-16.6009, expected range: -21.0838 -10.2971
Severely_persistent: rms_fgdepar=16.6009, expected range: 10.2900 21.1381
AUTOMATIC LAND SYNOP 2M TEMPERATURE (K) 04301 : out of range
2 times in the last 10 days for at least one item
Severe: avg_fgdepar=-15.9113, expected range: -16.5853 9.2746
Severe: rms_fgdepar=15.9668, expected range: 0.0000 15.0557
BUFR LAND SYNOP 2M TEMPERATURE (K) 04301 : out of range
2 times in the last 10 days for at least one item
Severe: avg_fgdepar=-16.2314, expected range: -17.1572 9.6794
Severe: rms_fgdepar=16.2565, expected range: 0.0000 15.5827
BUFR LAND SYNOP 2M TEMPERATURE (K) _MI1AF46 : out of range
Severe: avg_fgdepar=-12.3004, expected range: -14.4675 5.2632
Severe: rms_fgdepar=12.3054, expected range: 0.0000 14.4349
BUFR LAND SYNOP 2M TEMPERATURE (K) _MI1AFE9 : out of range
Severe: avg_fgdepar=-12.5129, expected range: -16.1799 6.9891
Severe: rms_fgdepar=12.5133, expected range: 0.0000 16.1893
rh2m
BUFR LAND SYNOP RH2M (%) 10534 : out of range
Severe: rms_fgdepar=35.5205, expected range: 0.0000 19.8597
BUFR LAND SYNOP RH2M (%) 10582 : out of range
Severe: rms_fgdepar=37.4238, expected range: 0.0000 19.6157