| Code/Flag Figure |
Description |
Status |
|
0
|
High-resolution data sample
|
Operational
|
|
1
|
Within 20 hPa of surface
|
Operational
|
|
2
|
Pressure less than 10 hPa (i.e., 9, 8, 7, etc.) when no other reason applies
|
Operational
|
|
3
|
Base pressure level for stability index
|
Operational
|
|
4
|
Begin doubtful temperature, height data
|
Operational
|
|
5
|
Begin missing data (all elements)
|
Operational
|
|
6
|
Begin missing relative humidity data
|
Operational
|
|
7
|
Begin missing temperature data
|
Operational
|
|
8
|
Highest level reached before balloon descent because of icing or turbulence
|
Operational
|
|
9
|
End doubtful temperature, height data
|
Operational
|
|
10
|
End missing data (all elements)
|
Operational
|
|
11
|
End missing relative humidity data
|
Operational
|
|
12
|
End missing temperature data
|
Operational
|
|
13
|
Zero degrees Celsius crossing(s) for RADAT
|
Operational
|
|
14
|
Standard pressure level
|
Operational
|
|
15
|
Operator-added level
|
Operational
|
|
16
|
Operator-deleted level
|
Operational
|
|
17
|
Balloon re-ascended beyond previous highest ascent level
|
Operational
|
|
18
|
Significant relative humidity level
|
Operational
|
|
19
|
Relative humidity level selection terminated
|
Operational
|
|
20
|
Surface level
|
Operational
|
|
21
|
Significant temperature level
|
Operational
|
|
22
|
Mandatory temperature level
|
Operational
|
|
23
|
Flight termination level
|
Operational
|
|
24
|
Tropopause(s)
|
Operational
|
|
25
|
Aircraft report
|
Operational
|
|
26
|
Interpolated (generated) level
|
Operational
|
|
27
|
Mandatory wind level
|
Operational
|
|
28
|
Significant wind level
|
Operational
|
|
29
|
Maximum wind level
|
Operational
|
|
30
|
Incremental wind level (fixed regional)
|
Operational
|
|
31
|
Incremental height level (generated)
|
Operational
|
|
32
|
Wind termination level
|
Operational
|
|
33
|
Pressure 100 to 110 hPa, when no other reason applies
|
Operational
|
|
34
|
Freezing level base
|
Operational
|
|
35
|
Freezing level top
|
Operational
|
|
36
|
Flight level base
|
Operational
|
|
37
|
Flight level top
|
Operational
|
|
38
|
Top of wind sounding
|
Operational
|
|
39
|
Bottom of wind sounding
|
Operational
|
|
40
|
Significant thermodynamic level (inversion)
|
Operational
|
|
41
|
Significant relative humidity level (according to NCDC criteria)
|
Operational
|
|
42
|
Significant temperature level (according to NCDC)
|
Operational
|
|
43
|
Begin missing wind data
|
Operational
|
|
44
|
End missing wind data
|
Operational
|
|
45-59
|
Reserved
|
Operational
|
|
60
|
Level of 80-knot isotach above jet
|
Operational
|
|
61
|
Level of 80-knot isotach below jet
|
Operational
|
|
62
|
Other
|
Operational
|
|
63
|
Missing value
|
Operational
|