Variables missing from 'scan_grib', but findable with xarray and cfgrib

I'm encountering an interesting issue where the results of scan_grib differ from interacting with a file via xarray/cfgrib. Particularly, it is not detecting certain variables. Installation information:

Python 3.11.0 | packaged by conda-forge | (main, Jan 14 2023, 12:27:40) [GCC 11.3.0] on linux
kerchunk.__version__ : '0.2.0'
cfgrib.__version__: '0.9.10.4'
xarray.__version__: '2023.5.0'

In this particular case, the missing variable is the 10 meter V wind component. Using scan_grib:

filter_stn10 = {"typeOfLevel":"heightAboveGround",  "level":10 }
gribfile = "./2021/anl/rap_252_20210415_0000_000.grb2"
scan = scan_grib(gribfile, filter=filter_stn10)
mzz = MultiZarrToZarr(scan,
    preprocess=drop(("time", "step")),
    concat_dims = ["heightAboveGround"],
    identical_dims=['latitude', 'longitude'])
d = mzz.translate()
fs = fsspec.filesystem("reference", fo=d)
m = fs.get_mapper("")
ds = xr.open_dataset(m, engine="zarr")
print(ds)

...
<xarray.Dataset>
Dimensions:            (heightAboveGround: 1, y: 225, x: 301, valid_time: 1)
Coordinates:
  * heightAboveGround  (heightAboveGround) int64 10
  * valid_time         (valid_time) datetime64[ns] 2021-04-15
Dimensions without coordinates: y, x
Data variables:
    latitude           (y, x) float64 ...
    longitude          (y, x) float64 ...
    u10                (heightAboveGround, y, x) float64 ...
Attributes:
    centre:             kwbc
    centreDescription:  US National Weather Service - NCEP
    edition:            2
    subCentre:          0

As you can see, there is no v10 variable output. Here's the printed output directly from scan_grib, showing that the data is missing here too:

[{'version': 1, 'refs': {'.zgroup': '{"zarr_format":2}', '.zattrs': '{"centre":"kwbc","centreDescription":"US National Weather Service - NCEP","edition":2,"subCentre":0}', 'u10/.zarray': '{"chunks":[225,301],"compressor":null,"dtype":"<f8","fill_value":3.4028234663852886e+38,"filters":[{"dtype":"float64","id":"grib","var":"u10"}],"order":"C","shape":[225,301],"zarr_format":2}', 'u10/0.0': ['{{u}}', 6501899, 70814], 'u10/.zattrs': '{"NV":0,"_ARRAY_DIMENSIONS":["y","x"],"cfName":"eastward_wind","cfVarName":"u10","dataDate":20210415,"dataTime":0,"dataType":"fc","endStep":0,"gridDefinitionDescription":"Lambert Conformal can be secant or tangent, conical or bipolar","gridType":"lambert","missingValue":3.4028234663852886e+38,"name":"10 metre U wind component","numberOfPoints":67725,"paramId":165,"shortName":"10u","stepType":"instant","stepUnits":1,"typeOfLevel":"heightAboveGround","units":"m s**-1"}', 'heightAboveGround/.zarray': '{"chunks":[1],"compressor":null,"dtype":"<i8","fill_value":null,"filters":null,"order":"C","shape":[1],"zarr_format":2}', 'heightAboveGround/0': '\n\x00\x00\x00\x00\x00\x00\x00', 'heightAboveGround/.zattrs': '{"_ARRAY_DIMENSIONS":["heightAboveGround"],"long_name":"height above the surface","positive":"up","standard_name":"height","units":"m"}', 'latitude/.zarray': '{"chunks":[225,301],"compressor":null,"dtype":"<f8","fill_value":null,"filters":[{"dtype":"float64","id":"grib","var":"latitude"}],"order":"C","shape":[225,301],"zarr_format":2}', 'latitude/0.0': ['{{u}}', 6501899, 70814], 'latitude/.zattrs': '{"_ARRAY_DIMENSIONS":["y","x"],"long_name":"latitude","standard_name":"latitude","units":"degrees_north"}', 'longitude/.zarray': '{"chunks":[225,301],"compressor":null,"dtype":"<f8","fill_value":null,"filters":[{"dtype":"float64","id":"grib","var":"longitude"}],"order":"C","shape":[225,301],"zarr_format":2}', 'longitude/0.0': ['{{u}}', 6501899, 70814], 'longitude/.zattrs': '{"_ARRAY_DIMENSIONS":["y","x"],"long_name":"longitude","standard_name":"longitude","units":"degrees_east"}', 'step/.zarray': '{"chunks":[1],"compressor":null,"dtype":"<f8","fill_value":null,"filters":null,"order":"C","shape":[1],"zarr_format":2}', 'step/0': '\x00\x00\x00\x00\x00\x00\x00\x00', 'step/.zattrs': '{"_ARRAY_DIMENSIONS":["step"],"long_name":"time since forecast_reference_time","standard_name":"forecast_period","units":"hours"}', 'time/.zarray': '{"chunks":[1],"compressor":null,"dtype":"<i8","fill_value":null,"filters":null,"order":"C","shape":[1],"zarr_format":2}', 'time/0': 'base64:AIJ3YAAAAAA=', 'time/.zattrs': '{"_ARRAY_DIMENSIONS":["time"],"calendar":"proleptic_gregorian","long_name":"initial time of forecast","standard_name":"forecast_reference_time","units":"seconds since 1970-01-01T00:00:00"}', 'valid_time/.zarray': '{"chunks":[1],"compressor":null,"dtype":"<i8","fill_value":null,"filters":null,"order":"C","shape":[1],"zarr_format":2}', 'valid_time/0': 'base64:AIJ3YAAAAAA=', 'valid_time/.zattrs': '{"_ARRAY_DIMENSIONS":["valid_time"],"calendar":"proleptic_gregorian","long_name":"time","standard_name":"time","units":"seconds since 1970-01-01T00:00:00"}'}, 'templates': {'u': './2021/anl/rap_252_20210415_0000_000.grb2'}}]

However, when I use xarray/cfgrib, the v10 variable is present and accounted for:

ds = xr.open_dataset(gribfile, engine="cfgrib", backend_kwargs={'filter_by_keys': filter_stn10})
print(ds)
...
<xarray.Dataset>
Dimensions:            (y: 225, x: 301)
Coordinates:
    time               datetime64[ns] ...
    step               timedelta64[ns] ...
    heightAboveGround  float64 ...
    latitude           (y, x) float64 ...
    longitude          (y, x) float64 ...
    valid_time         datetime64[ns] ...
Dimensions without coordinates: y, x
Data variables:
    u10                (y, x) float32 ...
    v10                (y, x) float32 ...
Attributes:
    GRIB_edition:            2
    GRIB_centre:             kwbc
    GRIB_centreDescription:  US National Weather Service - NCEP
    GRIB_subCentre:          0
    Conventions:             CF-1.7
    institution:             US National Weather Service - NCEP
    history:                 2023-09-08T16:40 GRIB to CDM+CF via cfgrib-0.9.1...

Output from wgrib2:

1:0:d=2021041500:REFC:entire atmosphere:anl:
2:26161:d=2021041500:VIS:surface:anl:
3:76622:d=2021041500:REFD:1000 m above ground:anl:
4:91602:d=2021041500:REFD:4000 m above ground:anl:
5:103208:d=2021041500:HGT:planetary boundary layer:anl:
6:200740:d=2021041500:GUST:surface:anl:
7:238099:d=2021041500:RETOP:entire atmosphere (considered as a single layer):anl:
8:267373:d=2021041500:HGT:100 mb:anl:
9:299862:d=2021041500:TMP:100 mb:anl:
10:316121:d=2021041500:RH:100 mb:anl:
11:327509:d=2021041500:VVEL:100 mb:anl:
12.1:335559:d=2021041500:UGRD:100 mb:anl:
12.2:335559:d=2021041500:VGRD:100 mb:anl:
13:374100:d=2021041500:HGT:125 mb:anl:
14:406398:d=2021041500:TMP:125 mb:anl:
15:423480:d=2021041500:RH:125 mb:anl:
16:436337:d=2021041500:VVEL:125 mb:anl:
17.1:446670:d=2021041500:UGRD:125 mb:anl:
17.2:446670:d=2021041500:VGRD:125 mb:anl:
18:486922:d=2021041500:HGT:150 mb:anl:
19:519400:d=2021041500:TMP:150 mb:anl:
20:537730:d=2021041500:RH:150 mb:anl:
21:553822:d=2021041500:VVEL:150 mb:anl:
22.1:565648:d=2021041500:UGRD:150 mb:anl:
22.2:565648:d=2021041500:VGRD:150 mb:anl:
23:608532:d=2021041500:HGT:175 mb:anl:
24:641616:d=2021041500:TMP:175 mb:anl:
25:660500:d=2021041500:RH:175 mb:anl:
26:681375:d=2021041500:VVEL:175 mb:anl:
27.1:694368:d=2021041500:UGRD:175 mb:anl:
27.2:694368:d=2021041500:VGRD:175 mb:anl:
28:738113:d=2021041500:HGT:200 mb:anl:
29:772347:d=2021041500:TMP:200 mb:anl:
30:790862:d=2021041500:RH:200 mb:anl:
31:817088:d=2021041500:VVEL:200 mb:anl:
32.1:831054:d=2021041500:UGRD:200 mb:anl:
32.2:831054:d=2021041500:VGRD:200 mb:anl:
33:876274:d=2021041500:HGT:225 mb:anl:
34:910505:d=2021041500:TMP:225 mb:anl:
35:928298:d=2021041500:RH:225 mb:anl:
36:958969:d=2021041500:VVEL:225 mb:anl:
37.1:974641:d=2021041500:UGRD:225 mb:anl:
37.2:974641:d=2021041500:VGRD:225 mb:anl:
38:1021922:d=2021041500:HGT:250 mb:anl:
39:1055864:d=2021041500:TMP:250 mb:anl:
40:1073010:d=2021041500:RH:250 mb:anl:
41:1107102:d=2021041500:VVEL:250 mb:anl:
42.1:1124398:d=2021041500:UGRD:250 mb:anl:
42.2:1124398:d=2021041500:VGRD:250 mb:anl:
43:1173425:d=2021041500:HGT:275 mb:anl:
44:1207228:d=2021041500:TMP:275 mb:anl:
45:1223656:d=2021041500:RH:275 mb:anl:
46:1258875:d=2021041500:VVEL:275 mb:anl:
47.1:1277338:d=2021041500:UGRD:275 mb:anl:
47.2:1277338:d=2021041500:VGRD:275 mb:anl:
48:1325698:d=2021041500:HGT:300 mb:anl:
49:1358872:d=2021041500:TMP:300 mb:anl:
50:1375309:d=2021041500:RH:300 mb:anl:
51:1412409:d=2021041500:VVEL:300 mb:anl:
52.1:1431873:d=2021041500:UGRD:300 mb:anl:
52.2:1431873:d=2021041500:VGRD:300 mb:anl:
53:1481013:d=2021041500:HGT:325 mb:anl:
54:1513807:d=2021041500:TMP:325 mb:anl:
55:1530216:d=2021041500:RH:325 mb:anl:
56:1568118:d=2021041500:VVEL:325 mb:anl:
57.1:1588258:d=2021041500:UGRD:325 mb:anl:
57.2:1588258:d=2021041500:VGRD:325 mb:anl:
58:1637414:d=2021041500:HGT:350 mb:anl:
59:1669796:d=2021041500:TMP:350 mb:anl:
60:1686108:d=2021041500:RH:350 mb:anl:
61:1724086:d=2021041500:VVEL:350 mb:anl:
62.1:1744937:d=2021041500:UGRD:350 mb:anl:
62.2:1744937:d=2021041500:VGRD:350 mb:anl:
63:1793360:d=2021041500:HGT:375 mb:anl:
64:1825237:d=2021041500:TMP:375 mb:anl:
65:1841628:d=2021041500:RH:375 mb:anl:
66:1879492:d=2021041500:VVEL:375 mb:anl:
67.1:1900565:d=2021041500:UGRD:375 mb:anl:
67.2:1900565:d=2021041500:VGRD:375 mb:anl:
68:1948191:d=2021041500:HGT:400 mb:anl:
69:1979803:d=2021041500:TMP:400 mb:anl:
70:1996163:d=2021041500:RH:400 mb:anl:
71:2033781:d=2021041500:VVEL:400 mb:anl:
72.1:2055147:d=2021041500:UGRD:400 mb:anl:
72.2:2055147:d=2021041500:VGRD:400 mb:anl:
73:2101958:d=2021041500:HGT:425 mb:anl:
74:2133393:d=2021041500:TMP:425 mb:anl:
75:2150030:d=2021041500:RH:425 mb:anl:
76:2187451:d=2021041500:VVEL:425 mb:anl:
77.1:2208831:d=2021041500:UGRD:425 mb:anl:
77.2:2208831:d=2021041500:VGRD:425 mb:anl:
78:2255515:d=2021041500:HGT:450 mb:anl:
79:2286390:d=2021041500:TMP:450 mb:anl:
80:2303182:d=2021041500:RH:450 mb:anl:
81:2341090:d=2021041500:VVEL:450 mb:anl:
82.1:2362485:d=2021041500:UGRD:450 mb:anl:
82.2:2362485:d=2021041500:VGRD:450 mb:anl:
83:2409552:d=2021041500:HGT:475 mb:anl:
84:2439985:d=2021041500:TMP:475 mb:anl:
85:2456849:d=2021041500:RH:475 mb:anl:
86:2494921:d=2021041500:VVEL:475 mb:anl:
87.1:2516387:d=2021041500:UGRD:475 mb:anl:
87.2:2516387:d=2021041500:VGRD:475 mb:anl:
88:2562680:d=2021041500:HGT:500 mb:anl:
89:2593117:d=2021041500:TMP:500 mb:anl:
90:2609777:d=2021041500:RH:500 mb:anl:
91:2647424:d=2021041500:VVEL:500 mb:anl:
92.1:2668671:d=2021041500:UGRD:500 mb:anl:
92.2:2668671:d=2021041500:VGRD:500 mb:anl:
93:2713923:d=2021041500:ABSV:500 mb:anl:
94:2746037:d=2021041500:HGT:525 mb:anl:
95:2776012:d=2021041500:TMP:525 mb:anl:
96:2792992:d=2021041500:RH:525 mb:anl:
97:2831347:d=2021041500:VVEL:525 mb:anl:
98.1:2852812:d=2021041500:UGRD:525 mb:anl:
98.2:2852812:d=2021041500:VGRD:525 mb:anl:
99:2898821:d=2021041500:HGT:550 mb:anl:
100:2928968:d=2021041500:TMP:550 mb:anl:
101:2945598:d=2021041500:RH:550 mb:anl:
102:2983308:d=2021041500:VVEL:550 mb:anl:
103.1:3004714:d=2021041500:UGRD:550 mb:anl:
103.2:3004714:d=2021041500:VGRD:550 mb:anl:
104:3049897:d=2021041500:HGT:575 mb:anl:
105:3079709:d=2021041500:TMP:575 mb:anl:
106:3096752:d=2021041500:RH:575 mb:anl:
107:3135210:d=2021041500:VVEL:575 mb:anl:
108.1:3156734:d=2021041500:UGRD:575 mb:anl:
108.2:3156734:d=2021041500:VGRD:575 mb:anl:
109:3202819:d=2021041500:HGT:600 mb:anl:
110:3232685:d=2021041500:TMP:600 mb:anl:
111:3249719:d=2021041500:RH:600 mb:anl:
112:3287641:d=2021041500:VVEL:600 mb:anl:
113.1:3309175:d=2021041500:UGRD:600 mb:anl:
113.2:3309175:d=2021041500:VGRD:600 mb:anl:
114:3354562:d=2021041500:HGT:625 mb:anl:
115:3384078:d=2021041500:TMP:625 mb:anl:
116:3401681:d=2021041500:RH:625 mb:anl:
117:3440059:d=2021041500:VVEL:625 mb:anl:
118.1:3461817:d=2021041500:UGRD:625 mb:anl:
118.2:3461817:d=2021041500:VGRD:625 mb:anl:
119:3508232:d=2021041500:HGT:650 mb:anl:
120:3537878:d=2021041500:TMP:650 mb:anl:
121:3555657:d=2021041500:RH:650 mb:anl:
122:3593791:d=2021041500:VVEL:650 mb:anl:
123.1:3615582:d=2021041500:UGRD:650 mb:anl:
123.2:3615582:d=2021041500:VGRD:650 mb:anl:
124:3661703:d=2021041500:HGT:675 mb:anl:
125:3691143:d=2021041500:TMP:675 mb:anl:
126:3709488:d=2021041500:RH:675 mb:anl:
127:3748175:d=2021041500:VVEL:675 mb:anl:
128.1:3770420:d=2021041500:UGRD:675 mb:anl:
128.2:3770420:d=2021041500:VGRD:675 mb:anl:
129:3817288:d=2021041500:HGT:700 mb:anl:
130:3846777:d=2021041500:TMP:700 mb:anl:
131:3865409:d=2021041500:RH:700 mb:anl:
132:3903940:d=2021041500:VVEL:700 mb:anl:
133.1:3926267:d=2021041500:UGRD:700 mb:anl:
133.2:3926267:d=2021041500:VGRD:700 mb:anl:
134:3973264:d=2021041500:HGT:725 mb:anl:
135:4002869:d=2021041500:TMP:725 mb:anl:
136:4021904:d=2021041500:RH:725 mb:anl:
137:4060819:d=2021041500:VVEL:725 mb:anl:
138.1:4083328:d=2021041500:UGRD:725 mb:anl:
138.2:4083328:d=2021041500:VGRD:725 mb:anl:
139:4130998:d=2021041500:HGT:750 mb:anl:
140:4160663:d=2021041500:TMP:750 mb:anl:
141:4180313:d=2021041500:RH:750 mb:anl:
142:4219649:d=2021041500:VVEL:750 mb:anl:
143.1:4242537:d=2021041500:UGRD:750 mb:anl:
143.2:4242537:d=2021041500:VGRD:750 mb:anl:
144:4290730:d=2021041500:HGT:775 mb:anl:
145:4320791:d=2021041500:TMP:775 mb:anl:
146:4340824:d=2021041500:RH:775 mb:anl:
147:4380169:d=2021041500:VVEL:775 mb:anl:
148.1:4403481:d=2021041500:UGRD:775 mb:anl:
148.2:4403481:d=2021041500:VGRD:775 mb:anl:
149:4451919:d=2021041500:HGT:800 mb:anl:
150:4482100:d=2021041500:TMP:800 mb:anl:
151:4502707:d=2021041500:RH:800 mb:anl:
152:4542641:d=2021041500:VVEL:800 mb:anl:
153.1:4566246:d=2021041500:UGRD:800 mb:anl:
153.2:4566246:d=2021041500:VGRD:800 mb:anl:
154:4615301:d=2021041500:HGT:825 mb:anl:
155:4645730:d=2021041500:TMP:825 mb:anl:
156:4666719:d=2021041500:RH:825 mb:anl:
157:4706917:d=2021041500:VVEL:825 mb:anl:
158.1:4730846:d=2021041500:UGRD:825 mb:anl:
158.2:4730846:d=2021041500:VGRD:825 mb:anl:
159:4779668:d=2021041500:HGT:850 mb:anl:
160:4810539:d=2021041500:TMP:850 mb:anl:
161:4832050:d=2021041500:RH:850 mb:anl:
162:4873044:d=2021041500:VVEL:850 mb:anl:
163.1:4897355:d=2021041500:UGRD:850 mb:anl:
163.2:4897355:d=2021041500:VGRD:850 mb:anl:
164:4945786:d=2021041500:HGT:875 mb:anl:
165:4977212:d=2021041500:TMP:875 mb:anl:
166:4999438:d=2021041500:RH:875 mb:anl:
167:5041862:d=2021041500:VVEL:875 mb:anl:
168.1:5066347:d=2021041500:UGRD:875 mb:anl:
168.2:5066347:d=2021041500:VGRD:875 mb:anl:
169:5114561:d=2021041500:HGT:900 mb:anl:
170:5146580:d=2021041500:TMP:900 mb:anl:
171:5169539:d=2021041500:RH:900 mb:anl:
172:5212900:d=2021041500:VVEL:900 mb:anl:
173.1:5237345:d=2021041500:UGRD:900 mb:anl:
173.2:5237345:d=2021041500:VGRD:900 mb:anl:
174:5285710:d=2021041500:HGT:925 mb:anl:
175:5318772:d=2021041500:TMP:925 mb:anl:
176:5342361:d=2021041500:RH:925 mb:anl:
177:5385536:d=2021041500:VVEL:925 mb:anl:
178.1:5409454:d=2021041500:UGRD:925 mb:anl:
178.2:5409454:d=2021041500:VGRD:925 mb:anl:
179:5458125:d=2021041500:HGT:950 mb:anl:
180:5492552:d=2021041500:TMP:950 mb:anl:
181:5516493:d=2021041500:RH:950 mb:anl:
182:5559001:d=2021041500:VVEL:950 mb:anl:
183.1:5581810:d=2021041500:UGRD:950 mb:anl:
183.2:5581810:d=2021041500:VGRD:950 mb:anl:
184:5630669:d=2021041500:HINDEX:surface:anl:
185:5648457:d=2021041500:HGT:975 mb:anl:
186:5684345:d=2021041500:TMP:975 mb:anl:
187:5708317:d=2021041500:RH:975 mb:anl:
188:5750512:d=2021041500:VVEL:975 mb:anl:
189.1:5771207:d=2021041500:UGRD:975 mb:anl:
189.2:5771207:d=2021041500:VGRD:975 mb:anl:
190:5820199:d=2021041500:TMP:1000 mb:anl:
191:5844251:d=2021041500:RH:1000 mb:anl:
192:5885460:d=2021041500:VVEL:1000 mb:anl:
193.1:5903388:d=2021041500:UGRD:1000 mb:anl:
193.2:5903388:d=2021041500:VGRD:1000 mb:anl:
194:5951381:d=2021041500:MSLMA:mean sea level:anl:
195:5973901:d=2021041500:HGT:1000 mb:anl:
196:6005539:d=2021041500:PRES:surface:anl:
197:6032368:d=2021041500:HGT:surface:anl:
198:6093540:d=2021041500:TMP:surface:anl:
199:6136917:d=2021041500:ASNOW:surface:0-0 day acc fcst:
200:6141452:d=2021041500:MSTAV:0 m underground:anl:
201:6185929:d=2021041500:WEASD:surface:anl:
202:6207731:d=2021041500:SNOD:surface:anl:
203:6226548:d=2021041500:TMP:2 m above ground:anl:
204:6264127:d=2021041500:POT:2 m above ground:anl:
205:6298296:d=2021041500:SPFH:2 m above ground:anl:
206:6348538:d=2021041500:DPT:2 m above ground:anl:
207:6389047:d=2021041500:DEPR:2 m above ground:anl:
208:6432553:d=2021041500:EPOT:surface:anl:
209:6474355:d=2021041500:RH:2 m above ground:anl:
210.1:6501899:d=2021041500:UGRD:10 m above ground:anl:
210.2:6501899:d=2021041500:VGRD:10 m above ground:anl:
211:6572713:d=2021041500:PRATE:surface:anl:
212:6578933:d=2021041500:APCP:surface:0-0 day acc fcst:
213:6579147:d=2021041500:ACPCP:surface:0-0 day acc fcst:
214:6579361:d=2021041500:WEASD:surface:0-0 day acc fcst:
215:6579575:d=2021041500:FROZR:surface:0-0 day acc fcst:
216:6579789:d=2021041500:FRZR:surface:0-0 day acc fcst:
217:6585662:d=2021041500:SSRUN:surface:0-0 day acc fcst:
218:6585876:d=2021041500:BGRUN:surface:0-0 day acc fcst:
219:6586090:d=2021041500:HGT:lowest level of the wet bulb zero:anl:
220:6644782:d=2021041500:CSNOW:surface:anl:
221:6645323:d=2021041500:CICEP:surface:anl:
222:6645712:d=2021041500:CFRZR:surface:anl:
223:6646316:d=2021041500:CRAIN:surface:anl:
224:6648381:d=2021041500:LFTX:500-1000 mb:anl:
225:6679044:d=2021041500:CAPE:surface:anl:
226:6693054:d=2021041500:CIN:surface:anl:
227:6713470:d=2021041500:PWAT:entire atmosphere (considered as a single layer):anl:
228:6744526:d=2021041500:LCDC:low cloud layer:anl:
229:6777549:d=2021041500:MCDC:middle cloud layer:anl:
230:6801650:d=2021041500:HCDC:high cloud layer:anl:
231:6825235:d=2021041500:TCDC:entire atmosphere:anl:
232:6861883:d=2021041500:HGT:convective cloud top level:anl:
233:6870105:d=2021041500:HGT:cloud base:anl:
234:6953196:d=2021041500:HGT:cloud top:anl:
235:7003356:d=2021041500:HLCY:3000-0 m above ground:anl:
236:7021427:d=2021041500:HLCY:1000-0 m above ground:anl:
237.1:7056753:d=2021041500:USTM:0-6000 m above ground:anl:
237.2:7056753:d=2021041500:VSTM:0-6000 m above ground:anl:
238.1:7123670:d=2021041500:VUCSH:0-6000 m above ground:anl:
238.2:7123670:d=2021041500:VVCSH:0-6000 m above ground:anl:
239:7203828:d=2021041500:PRES:tropopause:anl:
240:7229619:d=2021041500:TMP:tropopause:anl:
241:7253016:d=2021041500:POT:tropopause:anl:
242.1:7270630:d=2021041500:UGRD:tropopause:anl:
242.2:7270630:d=2021041500:VGRD:tropopause:anl:
243:7343782:d=2021041500:PRES:max wind:anl:
244.1:7377534:d=2021041500:UGRD:max wind:anl:
244.2:7377534:d=2021041500:VGRD:max wind:anl:
245:7454060:d=2021041500:TMP:80 m above ground:anl:
246:7485089:d=2021041500:SPFH:80 m above ground:anl:
247:7533905:d=2021041500:PRES:80 m above ground:anl:
248.1:7560656:d=2021041500:UGRD:80 m above ground:anl:
248.2:7560656:d=2021041500:VGRD:80 m above ground:anl:
249:7623695:d=2021041500:HGT:0C isotherm:anl:
250:7649318:d=2021041500:RH:0C isotherm:anl:
251:7675611:d=2021041500:PRES:0C isotherm:anl:
252:7701235:d=2021041500:HGT:highest tropospheric freezing level:anl:
253:7726687:d=2021041500:RH:highest tropospheric freezing level:anl:
254:7752641:d=2021041500:PRES:highest tropospheric freezing level:anl:
255:7777885:d=2021041500:TMP:30-0 mb above ground:anl:
256:7808855:d=2021041500:RH:30-0 mb above ground:anl:
257.1:7835801:d=2021041500:UGRD:30-0 mb above ground:anl:
257.2:7835801:d=2021041500:VGRD:30-0 mb above ground:anl:
258:7898095:d=2021041500:VVEL:30-0 mb above ground:anl:
259:7929464:d=2021041500:TMP:60-30 mb above ground:anl:
260:7960051:d=2021041500:RH:60-30 mb above ground:anl:
261.1:7988231:d=2021041500:UGRD:60-30 mb above ground:anl:
261.2:7988231:d=2021041500:VGRD:60-30 mb above ground:anl:
262:8048913:d=2021041500:VVEL:60-30 mb above ground:anl:
263:8086174:d=2021041500:TMP:90-60 mb above ground:anl:
264:8117502:d=2021041500:RH:90-60 mb above ground:anl:
265.1:8147117:d=2021041500:UGRD:90-60 mb above ground:anl:
265.2:8147117:d=2021041500:VGRD:90-60 mb above ground:anl:
266:8207930:d=2021041500:VVEL:90-60 mb above ground:anl:
267:8247025:d=2021041500:TMP:120-90 mb above ground:anl:
268:8278796:d=2021041500:RH:120-90 mb above ground:anl:
269.1:8310264:d=2021041500:UGRD:120-90 mb above ground:anl:
269.2:8310264:d=2021041500:VGRD:120-90 mb above ground:anl:
270:8371462:d=2021041500:VVEL:120-90 mb above ground:anl:
271:8410645:d=2021041500:TMP:150-120 mb above ground:anl:
272:8441827:d=2021041500:RH:150-120 mb above ground:anl:
273.1:8473432:d=2021041500:UGRD:150-120 mb above ground:anl:
273.2:8473432:d=2021041500:VGRD:150-120 mb above ground:anl:
274:8535142:d=2021041500:VVEL:150-120 mb above ground:anl:
275:8573559:d=2021041500:TMP:180-150 mb above ground:anl:
276:8604398:d=2021041500:RH:180-150 mb above ground:anl:
277.1:8634622:d=2021041500:UGRD:180-150 mb above ground:anl:
277.2:8634622:d=2021041500:VGRD:180-150 mb above ground:anl:
278:8697064:d=2021041500:VVEL:180-150 mb above ground:anl:
279:8734600:d=2021041500:4LFTX:180-0 mb above ground:anl:
280:8767961:d=2021041500:CAPE:180-0 mb above ground:anl:
281:8783098:d=2021041500:CIN:180-0 mb above ground:anl:
282:8803052:d=2021041500:HPBL:surface:anl:
283:8900795:d=2021041500:CAPE:90-0 mb above ground:anl:
284:8911585:d=2021041500:CIN:90-0 mb above ground:anl:
285:8919358:d=2021041500:CAPE:255-0 mb above ground:anl:
286:8934973:d=2021041500:CIN:255-0 mb above ground:anl:
287:8955339:d=2021041500:HGT:equilibrium level:anl:
288:9036520:d=2021041500:PLPL:255-0 mb above ground:anl:
289:9080430:d=2021041500:LTNG:surface:anl:
290:9081210:d=2021041500:RHPW:entire atmosphere:anl:
291:9102709:d=2021041500:SBT123:top of atmosphere:anl:
292:9151461:d=2021041500:SBT124:top of atmosphere:anl:
293:9216577:d=2021041500:SBT113:top of atmosphere:anl:
294:9261248:d=2021041500:SBT114:top of atmosphere:anl:

Any suggestions on what I may be doing wrong, or where the issue might lie? Happy to make a PR if there's a bug, just not sure if 1) there is one and 2) where to start addressing it.

Reproduce the report with scan_grib on the provided RAP GRIB2 file, using the heightAboveGround filter and the MultiZarrToZarr flow. Compare its output with xarray using the cfgrib engine, focusing on why u10 is emitted while v10 is absent. Done means the scan output and translated dataset include v10 consistently with cfgrib.