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ASCII Upper Air File

This type of file is generated by the uacvt program for use with other WXP upper air display programs.

FORMAT

The format of the file is as follows:

WXPUPAx
hhZ dd mmm yy
wwwww:iiii:aaaa:oooo 00HHH TTTtt dddff 92HHH TTTtt dddff 85HHH TTTtt dddff 70HHH TTTtt dddff
50HHH TTTtt dddff 40HHH TTTtt dddff 30HHH TTTtt dddff 25HHH TTTtt dddff
20HHH TTTtt dddff 15HHH TTTtt dddff 10HHH TTTtt dddff 07HHH TTTtt dddff
05HHH TTTtt dddff 03HHH TTTtt dddff 02HHH TTTtt dddff 01HHH TTTtt dddff
88ppp TTTtt dddff 77ppp dddff
ppp TTTtt ppp TTTtt ...
ppp TTTtt ppp TTTtt ... X
hh dddff hh dddff ...
hh dddff hh dddff ... $

Header Format

The first line of the file is the string:

WXPUPAx

which is used to determine file type. The second line of the data file contains the date and time in the following format:

hhZ dd mmm yy

Where:

hh -- Hour of the observation in GMT
dd -- Day of the observation
mmm -- A three letter abbreviation for the month
yy -- The last two digits of the year

Example: 12Z 24 JUN 98

Data Format

The data are entered on the following lines. This format listed below contains twelve lines of data for each individual station, which are in the following format:

Line 1-5: Mandatory level data to 500 mb (from TTAA, TTCC, or PPAA)

[wwwww:]iiii[:aaaa:oooo] 00HHH TTTtt dddff 92HHH TTTtt dddff 85HHH TTTtt dddff 70HHH TTTtt dddff
50HHH TTTtt dddff 40HHH TTTtt dddff 30HHH TTTtt dddff 25HHH TTTtt dddff
20HHH TTTtt dddff 15HHH TTTtt dddff 10HHH TTTtt dddff 07HHH TTTtt dddff
05HHH TTTtt dddff 03HHH TTTtt dddff 02HHH TTTtt dddff 01HHH TTTtt dddff
88ppp TTTtt dddff 77ppp dddff

Where:

  • wwwww -- WMO number for the observation site (optional).
  • iiii -- ICAO Station identifier.
    If the station does not have an ICAO ID, one will be derived from the WMO number using the 2 letter country prefix and the last 3 numbers of the WMO number.  Country prefixes are listed in the Global Station Information Appendix.
  • aaaa -- Station latitude (optional).
  • oooo -- Station longitude (optional).
  • PP -- Pressure level (see below). The value "88" represents tropopause data. The value "77" represents maximum wind level data.  In these cases pressure of the level is reported instead of height.
  • ppp -- Pressure of level. (999 for missing)
  • HHH -- Height in meters. (999 for missing)
    PP Pressure Code(H) Height Code(H) Height
    00 1000 mb H < 500 H H >= 500 500-H
    92 925 mb all H H    
    85 850 mb all H H+1000    
    70 700 mb H < 500 H+3000 H >= 500 H+2000
    50 500 mb all H H*10    
    40 400 mb all H H*10    
    30 300 mb H < 500 H*10+10000 H >= 500 H*10
    25 250 mb H < 500 H*10+10000 H >= 500 H*10
    20 200 mb all H H*10+10000    
    15 150 mb all H H*10+10000    
    10 100 mb all H H*10+10000    
    07 70 mb all H H*10+10000    
    05 50 mb H < 500 H*10+20000 H >= 500 H*10+10000
    03 30 mb all H H*10+20000    
    02 20 mb all H H*10+20000    
    01 10 mb H < 500 H*10+30000 H >= 500 H*10+20000
  • TTT -- Temperature at the pressure level in .1 C. (999 for missing)
    If the tenths digit is odd, the temperature is negative. Otherwise, the temperature is positive. For example, 234 is 23.4C whereas 123 is -12.3C.
  • tt -- Dewpoint depression in C. (99 for missing)
    If tt is less than or equal to 50, then the dewpoint depression is in tenths of a C. Otherwise, tt is the dewpoint depression in C plus 50. For example, 65 gives a dewpoint depression of 15C, whereas 17 gives a depression of 1.7C.
  • ddd -- Wind direction to the nearest 5 degrees (999 for missing)
  • ff -- Wind speed in knots (99 for missing)
    If ddd is not an even multiple of 5, the difference between ddd and an even multiple of 5 is then added to the wind speed as the hundredths digit. For example, 31523 (dddff) is 315_ at 23 knots whereas 25612 is 255_ at 112 knots.

If all the information for a particular group is missing, it is encoded as an "X".

Next Lines: Significant reporting levels ( 50 maximum from TTBB and TTDD reports)

Format:

ppp TTTtt ppp TTTtt ...

Where:

  • ppp -- Pressure of significant level
    If pressure is greater than 1000 mb, ppp is the pressure minus 1000.
  • TTTtt -- is encoded same as TTAA data listed above.

Information terminated with "X"

Next Lines: Wind level information (50 maximum from PPBB and PPDD reports)

Format:

hh dddff hh dddff ...

Where:

  • hh -- Height of the wind level is 1000s of feet.
  • dddff -- is encoded as listed above

Information terminated with "$"

EXAMPLES

An example of a converted report would be as follows:

72456:KTOP:39.07:-95.62 00121 X X 92806 22212 19012 85541 18618 24019 70189 10459 25042
50589 06164 26032 40760 16718 23537 30971 30758 24035 25097 41358 23538
20245 53557 24043 15425 64963 25515 10672 64566 28503 07889 62372 07014
05100 57575 05012 X X X X X X X X X
88147 65763 26016 X X
983 26639 947 23019 890 21628 839 17817 819 18257 788 15856 769 16058
678 08860 592 01501 548 04300 533 04911 526 06156 525 05959 510 05359
484 07565 479 08361 476 08548 448 11907 390 18309 359 21346 317 28550
286 33360 235 44760 216 49556 183 57559 133 66762  94 64967  92 65967
 61 60174  45 56375 X
00 12007 01 12507 02 14511 03 22514 04 24018 06 23520 07 23523
08 24531 09 25537 10 25540 11 24545 12 24044 14 24538 16 26026
18 26526 20 25535 25 23537 26 23038 30 24037 35 23534 43 25544
44 26012 46 24513 49 27514 50 28008 54 29502 55 28503 62 06511
63 09011 70 05018 $

Where:

  • KTOP is Topeka KS (WMO 72456, Lat=39.07, Lon=-95.62)

Mandatory level data (miss is missing data)

Code Level Pres (mb) Hght (m) Temp (C) Depr (C) W Dir (deg) W Spd (knt)
00121 X X   1000 121 miss miss miss miss
92806 22212 19012   925 806 22.2 1.2 190 12
85541 18618 24019   850 1541 18.6 1.8 240 19
70189 10459 25042   700 3189 10.4 9 250 42
50589 06164 26032   500 5890 -6.1 14 260 32
40760 16718 23537   400 7600 -16.7 1.8 235 37
30971 30758 24035   300 9710 -30.7 8 240 35
25097 41358 23538   250 10970 -41.3 8 235 38
20245 53557 24043   200 12450 -53.5 7 240 43
15425 64963 25515   150 14250 -64.9 13 255 15
10672 64566 28503   100 16720 -64.5 16 285 3
07889 62372 07014   70 18890 -62.3 22 70 14
05100 57575 05012   50 20100 -57.5 25 50 12
X X X   30 miss miss miss miss miss
X X X   20 miss miss miss miss miss
X X X   10 miss miss miss miss miss
88147 65763 26016 Trop 147   -65.7 13 260 16
X X Max Wind miss       miss miss

Significant level data

Code Level Pres (mb) Temp (C) Depr (C)
983 26639 SFC 983 26.6 3.9
947 23019   947 23.0 1.9
890 21628   890 21.6 2.8
839 17817   839 17.8 1.7
819 18257   819 18.2 7
788 15856   788 15.8 6
769 16058   769 16.0 8
...        
133 66762   133 -66.7 12
94 64967   94 -64.9 17
92 65967   92 -65.9 17
61 60174   61 -60.1 24
45 56375   45 -56.3 25

Wind level data

Code Level Hght (ft) W Dir (deg) W Spd (knt)
00 12007 SFC SFC 120 7
01 12507   1000 125 7
02 14511   2000 145 11
03 22514   3000 225 14
04 24018   4000 240 18
06 23520   6000 235 20
07 23523   7000 235 23
...        
54 29502   54000 295 2
55 28503   55000 285 3
62 06511   62000 65 11
63 09011   63000 90 11
70 05018   70000 50 18

A sample upper air converted file would look like:

WXPUPAx
0000Z  3 AUG 98
01001:ENJA:70.93:-8.67 00047 06612 15514 92686 04203 16518 85374 05256 17517 709
33 03567 15520
50552 16929 15020 40716 27923 17021 30916 43199 21019 25036 53999 22015
20178 48799 20012 15370 45199 22511 10640 45599 22510 07879 44399 20007
05104 44999 26506 03446 43199 00000 02722 39387 13514 01201 X X
88227 58399 22018 X X
005 06010 993 06806 894 03004 855 05250 779 01270 731 02365 644 06576
613 09758 585 12365 573 13562 558 15514 528 17507 522 16115 468 19727
393 29120 389 28949 368 31362 314 40799 239 56799 227 58399 214 58799
205 49599 193 47999 171 45399 127 44399  89 45999  33 44399  17 39787
 15 34589  14 37188  11 36588 X
00 13509 $
01028:ENBJ:74.52:19.02 00088 05834 26510 92720 00400 29014 85397 00507 30522 709
40 06550 29015
...

FILES

  • upa.cty -- used as cross reference between WMO number and ICAO ID.

SEE ALSO


For further information about WXP, email technical-support@weather.unisys.com
Last updated by Dan Vietor on August 3, 1998