Many people have shown signs of frustration when trying to decode a dropsonde report from the recon crews. With a lack of online decoders, this can pose a problem. Not only can it frustrate the user, but it can also spread misinformation, such as incorrect winds speeds or incorrect surface pressure.

Don’t fret, however. Today, I will break down the code for you!

First, we’ll take a look at a dropsonde from a training mission on 3 August 2007.

UZNT13 KNHC 031736
XXAA 53178 99276 70885 08178 99017 25823 21512 00147 24418 22013
92829 20814 26515 85560 18241 26015 88999 77999
31313 09608 81727
51515 10190 70196
61616 AF308 WXWXA 07080315308 OB 05
62626 SPL 2763N08851W 1730 MBL WND 23013 AEV 00000 DLM WND 25513
017780 WL150 21512 075 =
XXBB 53178 99276 70885 08178 00017 25823 11962 22202 22907 20018
33895 20256 44850 18241 55780 14607 66700 07400
21212 00017 21512 11986 23015 22962 24511 33947 27012 44924 26515
55850 26015 66780 26513 77700 23010
31313 09608 81727
51515 10190 70196
61616 AF308 WXWXA 07080315308 OB 05
62626 SPL 2763N08851W 1730 MBL WND 23013 AEV 00000 DLM WND 25513
017780 WL150 21512 075 =

First line is the standard bulletin header. Dropsondes are transmitted as UZNT13. The ICAO is KNHC for AFRES flights (KBIX for backup) and KWBC for NOAA flights. 031736 is the DTG of the 3rd at 1736Z.

XXAA is the indicator for the temperature drop group.

53178 is the date/time group. 53 is the date after subtracting 50. (53-50=3rd) 17 is the time, in hours. (17Z). 8 is the highest mandatory level reported. (850mb)

99276 is the latitude group. 99 is the indicator. 276 is the latitude in tenths of a degree. (27.6°)

70885 is the longitude group. 7 is the octant of the globe. 0885 is the longitude in tenths of a degree. (88.5°)

08178 is the Marsden Square group. 081 is the Marsden square. 78 is the units digits in the reported latitude/longitude.

99017 25823 21512 is the sea level pressure group. 99 indicates the surface level. 017 is the pressure in whole millibars, thousands omitted. (1017mb) 258 is the air temperature in tenths of a degree, Celsius. (25.8°C) (Note: if the last digit is even, the temperature is positive, odd is negative.) 23 is the dewpoint depression. (2.3°C or a dewpoint of 23.5°C) (Dewpoint depressions of 4.9°C or less are encoded to the tenth of a degree. 5.0 to 5.4°C are encoded as 50. 5.5-5.9°C are encoded as 56. 6.0°C and above are encoded with 50 added. [8°C is encoded as 58], if RH% is <20%, 80 is encoded. If air temperature is <-40°C, the field is reported as missing: //) 21512 is the wind. (215° at 12KT) (If the middle number is not a 0 or 5, note the following. If the middle number is a 1 or 6, add 100 to the wind speed. 21612 = 215° at 112KT. If the middle number is a 2 or 7, add 200 to the wind speed. 21712 = 215 @ 212KT.)

All missing information will be encoded with slashes. ( / )

To repeat the surface group (without the explaination…)
99017 25823 21512 = Surface pressure: 1017mb; Temperature: 25.8°C, Dewpoint: 23.5°C, Wind: 215° @ 12KT.

The next groups of three will be each standard isobaric level. 99 was the indicator for the surface, 00 for 1000mb, 92 for 925mb, 85 for 850mb, 70 for 700mb, 50 for 500mb, 40 for 400mb, 30 for 300mb, 25 for 250mb.

Instead of pressure in these groups, the standard isobaric level height is listed, in geopotential meters. At and above 500mb, heights are in decameters, with any thousands or tens of thousands omitted. For 1000mb and 925mb heights than are negative, 500 is added. When the pressure is less than the isobaric level, slashes are encoded. (SLP = 950mb: 00/// ///// /////.)

00147 24418 22013 = 1000mb height: 147m, Temp: 24.4°C, Dewpoint: 22.6°C, Wind: 220° @ 13KT.

92829 20814 26515 = 925mb height: 829m, Temp: 20.8°C, Dewpoint: 19.4°C, Wind: 265° @ 15KT.

85560 18241 26015 = 850mb height: 1560m, Temp: 18.2°C, Dewpoint: 14.1°C, Wind: 260° @ 15KT.

88999 = 88 is the tropopause height group. 88 is the tropopause indicator. 999 is the height, in millibars, of the tropopause. 999 is encoded when the tropopause was not observed. If one is observed, temp, dewpoint depression, and wind data, like above, will follow.

77999 = 77 is the max wind group. Like above, 999 is the height, in millibars, of the max wind. 999 is encoded when the max wind was not reported. If one is observed, wind data, like above, will follow along with any wind shear data.

31313 09608 81727 = 31313 is the sounding system indicator. 0 indicates any solar/infrared radiation correction. (0 = none) 96 is the radiosonde/sounding system used. (96 = descending radiosonde or dropsonde) 08 is the tracking technique. (08 = GPS) 81727 is the time group. (8= indicator, 1727 = time, in zulu)

51515 10190 70196 = 51515 is the additional data indicator. If the second group of numbers is 10166, the geopotential data are doubtful between the following levels. If 10167, the temperature data are doubtful between the following levels. If 10190, extrapolated altitude data follows. If 10191, extrapolated surface pressure follows. In this case, since the number is 10190, 70196 indicates that the 700mb height is extrapolated to be 3196m.

61616 AF308 WXWXA 07080315308 OB 05 = Aircraft and mission identification group. 61616 is the indicator for this group. AF indicates this is an AFRES crew (versus NOAA crew) and the last three digits of the aircraft’s tail number is 308. The remaining information signals what type of mission is being flow. In this case, it’s a training or transient mission. If it was on an actual system, invest or cyclone information would be listed.

62626 = Nationally developed codes indicator

SLP 2763N08851W 1730 = Impact location of the sonde based on its last GPS position and the splash time. (27.63°N 88.51°W, splash time of 1730Z)

MBL WND 23013 = Mean boundary level (lowest 500m) wind. (230° @ 13KT)

AEV 00000 = Software version for this sounding.

DLM WND 25513 017780 = Deep layer mean wind. The average wind between the first and last significant levels of the sounding. (255° @ 13KT between 1017mb and 780mb)

WL150 21512 075 = Average wind over the lowest 150m of the sounding. (215° @ 12KT centered at 75m)

XXBB is the indicator for the significant temperature and wind drop group.

53178 is the date/time group. 53 is the date after subtracting 50. (53-50=3rd) 17 is the time, in hours. (17Z). 8 is the highest mandatory level reported. (850mb)

99276 is the latitude group. 99 is the indicator. 276 is the latitude in tenths of a degree. (27.6°)

70885 is the longitude group. 7 is the octant of the globe. 0885 is the longitude in tenths of a degree. (88.5°)

08178 is the Marsden Square group. 081 is the Marsden square. 78 is the units digits in the reported latitude/longitude.

00017 25823 = Pressure 1017mb, Temperature: 25.8°C, Dewpoint: 23.5°C

11962 22202 = Pressure 962mb, Temperature: 22.2°C, Dewpoint: 22.0°C

22907 20018 = Pressure 907mb, Temperature: 20.0°C, Dewpoint: 18.2°C

33895 20256 = Pressure 895mb, Temperature: 20.2°C, Dewpoint: 14°C

44850 18321 = Pressure 850mb, Temperature: 18.3°C, Dewpoint: 16.2°C

55780 14607 = Pressure 780mb, Temperature: 14.6°C, Dewpoint: 13.9°C

66700 07400 = Pressure 700mb, Temperature: 7.4°C, Dewpoint: 7.4°C

21212 = Indicates the following are wind levels

00017 21512 = Pressure 1017mb, Wind 215° @ 12KT

11986 23015 = Pressure 986mb, Wind 230° @ 15KT

22962 24511 = Pressure 962mb, Wind 245° @ 11KT

33947 27012 = Pressure 947mb, Wind 270° @ 12KT

44924 26515 = Pressure 924mb, Wind 265° @ 15KT

55850 26015 = Pressure 850mb, Wind 260° @ 15KT

66780 26513 = Pressure 780mb, Wind 265° @ 13KT

77700 23010 = Pressure 700mb, Wind 230° @ 10KT

The rest of the data is the same as in the XXAA group.


I’ll post a couple more examples, without commentary. Of course, feel free to ask ANY questions you may have.

The following dropsonde is from a recent NOAA synoptic mission on Hurricane Dean. While typical AFRES fix missions only provide data for the lowest 5,000 to 10,000 feet of the atmosphere, the NOAA synoptic missions provide a bigger slice of the atmosphere. Below, I will decode this for your enjoyment and understanding.

UZNT13 KWBC 200828
XXAA 70082 99160 70793 04469 99003 24806 ///// 00024 24405 25025
92708 23800 19534 85443 17614 20533 70087 10037 22533 50581 05313
21030 40754 13517 20014 30967 27329 26531 25096 37936 28029 20245
505// 25527 88999 77999
31313 09608 80811
51515 10190 15426
61616 NOAA9 1204A DEAN OB 09
62626 SPL 1603N07927W 0825 LST WND 019 MBL WND 24029 AEV 00000 DL
M WND 22527 001161 WL150 24527 094 =
XXBB 70088 99160 70793 04469 00003 24806 11969 22600 22962 24000
33955 22600 44904 23600 55892 20401 66850 17614 77774 15056 88660
08656 99569 00710 11372 16520 22315 24527 33274 32332 44218 45345
55205 49156 66154 64319
21212 00003 ///// 11001 25024 22995 24527 33970 24028 44962 24035
55957 23028 66948 23034 77932 20528 88922 19536 99902 19534 11892
20538 22871 20530 33850 20533 44727 20534 55682 23035 66621 21035
77486 21032 88446 18037 99408 20515 11394 19013 22386 21011 33373
23516 44348 26022 55312 26532 66295 26028 77278 28027 88248 28029
99224 25029 11209 26030 22185 24517 33171 22514 44161 23507 55154
21016
31313 09608 80811
51515 10190 15426
61616 NOAA9 1204A DEAN OB 09
62626 SPL 1603N07927W 0825 LST WND 019 MBL WND 24029 AEV 00000 DL
M WND 22527 001161 WL150 24527 094 =

20th at 08Z. 850mb is the highest mandatory level reported.
16.0°N 79.3°W
1003mb, 24.8°C/24.2°C, Wind unavailable
1000mb height is 24m, 24.4°C/23.9°C, 250° 25KT
925mb height is 708m, 23.8°C/23.8°C, 195° 34KT
850mb height is 1443m, 17.6°C/16.2°C, 205° 33KT
700mb height is 3087m, 10.0°C/6.3°C, 225° 33KT
500mb height is 5810m, -5.3°C/-6.6°C, 210° 30KT
400mb height is 7540m, -13.5°C/-15.2°C, 200° 14KT
300mb height is 9670m, -27.3°C/-30.2°C, 265° 31KT
250mb height is 10960m, -27.9°C/-31.5°C, 280° 29KT
200mb height is 12450m, -50.5°C/unknown, 255° 27KT
No tropopause or max wind data available
Standard GPS dropsonde at 0811Z.
150mb height of 14260m.
This is observation number nine from NOAA9 aircraft flying the twelve mission of Hurricane Dean, the fourth storm of the year.
Dropsonde impact was at 16.03°N 79.27°W and splashed at 0825Z.
Last wind reported was at 19m from the surface.
Mean wind below 500m was 240° 29KT
Mean wind between 1001mb and 161mb was 225° 27KT
Mean wind below 150m was 245° 27KT, centered at 94m.
1003mb: 24.8°C/24.2°C
969mb: 22.6°C/22.6°C
962mb: 24.0°C/24.0°C
955mb: 22.6°C/22.6°C
904mb: 23.6°C/23.6°C
892mb: 20.4°C/20.3°C
850mb: 17.6°C/16.2°C
774mb: 15.0°C/9°C
660mb: 8.6°C/3°C
569mb: -0.7°C/-1.7°C
372mb: -16.5°C/-18.5°C
315mb: -24.5°C/-27.2°C
274mb: -32.3°C/-35.5°C
218mb: -45.3°C/-49.8°C
205mb: -49.1°C/-55°C
154mb: -64.3°C/-66.2°C
1003mb: Unknown wind
1001mb: 250° 24KT
995mb: 245° 27KT
970mb: 240° 28KT
962mb: 240° 35KT
957mb: 230° 28KT
948mb: 230° 34KT
932mb: 205° 28KT
922mb: 195° 36KT
902mb: 195° 34KT
892mb: 205° 38KT
871mb: 205° 30KT
850mb: 205° 33KT
727mb: 205° 34KT
682mb: 230° 35KT
621mb: 210° 35KT
486mb: 210° 32KT
446mb: 180° 37KT
406mb: 205° 15KT
394mb: 190° 13KT
386mb: 210° 11KT
373mb: 235° 16KT
348mb: 260° 22KT
312mb: 265° 32KT
295mb: 260° 28KT
278mb: 280° 27KT
248mb: 280° 29KT
224mb: 250° 29KT
209mb: 260° 30KT
185mb: 245° 17KT
171mb: 225° 14KT
161mb: 235° 7KT
154mb: 210° 16KT

The following dropsonde is from an AFRES fix mission on Hurricane Charley (2004) just before landfall. The drop was taking within the eyewall and helps demonstrate extreme winds within these reports.

UZNT13 KNHC 131919
XXAA 63197 99264 70823 08162 99961 26200 ///// 00855 ///// /////
92334 23400 ///// 85073 20400 14133 70740 15027 22622 88999 77999
31313 09608 81907
61616 AF963 0903A CHARLEY OB 27
62626 EYEWALL 000 SPL 2657N08226W 1913 LST WND 823 AEV 20504 DLM
WND 15122 875721 =
XXBB 63198 99264 70823 08162 00961 26200 11948 23800 22850 20400
33772 17618 44751 15408 55747 16830 66718 14013 77714 15856 88692
14415
21212 00961 ///// 11875 13131 22865 13632 33846 14133 44692 23122
31313 09608 81907
61616 AF963 0903A CHARLEY OB 27
62626 EYEWALL 000 SPL 2657N08226W 1913 LST WND 823 AEV 20504 DLM
WND 15122 875721 =


13th at 19Z. 700mb is the highest mandatory level reported.
26.4°N 82.3°W
961mb, 26.2°C/26.2°C, Wind unavailable
1000mb height is -355m, Temperature, dewpoint, and wind unavailable
925mb height is 334m, 23.4°C/23.4°C, Wind unavailable
850mb height is 1073m, 20.4°C/20.4°C, 140° 133KT
700mb height is 2740m, 15.0°C/12.3°C, 225° 122KT
No tropopause or max wind data available
Standard GPS dropsonde at 1907Z.
This is observation number twenty-seven from AF963 aircraft flying the ninth mission of Hurricane Charley, the third storm of the year.
Dropsonde taken within the eyewall.
Dropsonde impact was at 26.57°N 82.26°W and splashed at 1913Z.
Last wind reported was at 823m from the surface.
Mean wind between 875mb and 721mb was 150° 122KT
961mb: 26.2°C/26.2°C
948mb: 23.8°C/23.8°C
850mb: 20.4°C/20.4°C
772mb: 17.6°C/15.8°C
751mb: 15.4°C/14.6°C
747mb: 16.8°C/13.8°C
718mb: 14.0°C/12.7°C
714mb: 15.8°C/10°C
692mb: 14.4°C/12.9°C
961mb: Wind unavailable
875mb: 130° 131KT
865mb: 135° 132KT
846mb: 140° 133KT
692mb: 230° 122KT

The following dropsonde is from an AFRES fix mission on Hurricane Wilma (2005) at the record intensity of 884mb. The drop was taking within the eye and helps demonstrate extreme low pressure within these reports.


XXAA 69088 99171 70823 04572 99884 27023 17023 00/// ///// /////
92/// ///// ///// 85349 24619 18519 70069 26469 88999 77999
31313 09608 80800
61616 AF308 0724A WILMA OB 17
62626 EYE SPL 1707N08232W 0803 MBL WND 18520 AEV 20507 DLM WND 19
514 884766 WL150 18022 081 =
XXBB 69088 99171 70823 04572 00884 27023 11850 24619 22846 24422
33824 27260 44804 28463 55697 26470
21212 00884 17023 11850 18519 22822 20514 33810 19511 44802 21510
55766 17003 66697 06507
31313 09608 80800
61616 AF308 0724A WILMA OB 17
62626 EYE SPL 1707N08232W 0803 MBL WND 18520 AEV 20507 DLM WND 19
514 884766 WL150 18022 081 =

19th at 08Z. 850mb is the highest mandatory level reported.
17.1°N 82.3°W
884mb, 27.0°C/24.7°C, 170° 23KT
1000mb data is unavailable
925mb data is unavailable
850mb height is 349m, 24.6°C/22.7°C, 185° 19KT
700mb height is 1069m, 26.4°C/7°C, Wind is unavailable
No tropopause or max wind data available
Standard GPS dropsonde at 0800Z.
This is observation number seventeen from AF308 aircraft flying the seventh mission of Hurricane Wilma, the twenty-fourth storm of the year.
Dropsonde taken within the eye.
Dropsonde impact was at 17.07°N 82.32°W and splashed at 0803Z.
Mean wind below 500m was 185° 20KT
Mean wind between 884mb and 766mb was 195° 14KT
Mean wind below 150m was 180° 22KT, centered at 81m.
884mb: 27.0°C/24.7°C
850mb: 24.6°C/22.7°C
846mb: 24.4°C/22.2°C
824mb: 27.2°C/17°C
804mb: 28.4°C/15°C
697mb: 26.4°C/6°C
884mb: 170° 23KT
850mb: 185° 19KT
822mb: 205° 14KT
810mb: 195° 11KT
802mb: 215° 10KT
766mb: 170° 3KT
697mb: 065° 7KT

Sorry about this post. I am deleting it as best that I can, because it was probably off topic.

As a Dropsonde Operator (I drop the sondes in the planes)

Here is an explanation that our weather officers give us.

UZNT13 KNHC 061851
XXAA 56185 99251 70786 08158 99016 26444 18501 00140 26247 07004 92827
22856 10509 85560 17834 07510 70200 09045 07012 50591 05532 07016 88999
77999
61616 AF968 0204A BONNIE OB 04
62626 RAINBAND SPL 2635N08996W LST WND 001 MBL WND 04010
XXBB 56188 99251 70786 08158 00016 26444 11005 25841 2291 26657 33860
18233 44719 10657 55679 07023 66624 03656 77555 01917 88541 02556 99523
11497 05927
21212 00016 18501 11983 07510 22959 10010 33865 09511
44787 06510 55719 08011 66695 06512 77646 08512 88597 07011 99570 03511
11538 08014 22523 08516 33497 07016
31313 09608 81828
51515 10166 02050
61616 AF968 0204A BONNIE OB 04
62626 RAINBAND SPL 2635N08996W LST WND 001 MBL WND 04010

XXAA – Identifier for a temp drop code
Date/Time Group: YYGGId
• Identifier: YY – Date Group, Identifier: GG – Time Group, Identifier: Id - The highest mandatory level for which wind is available
LATTITUDE: 99LaLaLa
• Identifier: 99 – Indicator for data on position, Identifier: LaLaLa – Latitude in tenths of degrees
LONGITUDE: QcLoLoLoLo
• Identifier: Qc – The octant of the globe, Identifier: LoLoLoLo – Longitude in tenths of degrees
MARSDEN SQUARE: MMMUlaUlo
• Identifier and explain: MMM – Marsden square, Identifier and explain: UlaUlo – Units (marsdens square you can find on wikipedia)
SEA LEVEL PRESSURE: 99PoPoPo ToToToDoDo dodofofofo
• Identifier: 99 – Indicator for data at the surface level follows
• Identifier: PoPoPo –Pressure of specified levels in whole millibar (thousands digit omitted)
• Identifier: ToToTo – Tens and digits of air temperature (not rounded off) in degrees Celsius, at specified levels beginning with surface
• Identifier: DoDo – Dewpoint depression at standard isobaric surfaces beginning with surface level
NOTE
When the depression is 4.9C or less encode the units and tenths digits of the depression. Encode depressions of 5.0 through 5.4C as 50. Encode depressions of 5.5C through 5.9C as 56. Dew point
repressions of 6.0 and above are encoded in tens and units with 50 added. Dew point depressions for relative humidities less then 20% are encoded as 80. When air temperature is below –40C report DaDa as // Identifier: dodo – True direction from which the wind is blowing rounded to nearest 5 degrees. Report hundreds and tens digits. The unit (0 and 5) is added to the hundreds digit of wind.
• Identifier: fofofo – Wind speed in knots. Hundreds digit is sum of hundreds digit of speed and unit digit of direction. Example: 295 degrees at 125 knots is encoded as 29625
STANDARD ISOBARIC SURFACES: P1P1h1h1h1 T1T1T1D1D1 d1d1f1f1f1
• Identifier: P1P1 – Pressure of standard isobaric surfaces in units of tens of millibars. (1000mbs = 00, 925mbs = 92, 850mbs = 85, 700mbs = 70, 500mbs = 50, 400mbs = 40, 300mbs = 30, 250mbs = 25)
• Identifier: h1h1h1 – Heights of the standard pressure level in geopotential meters or decameters above the surface. Encoded in decameters at and above 500mbs omitting, if necessary, the thousands or tens of thousands digits. Add 500 to hhh for negative 1000mb or 925mb heights. Report 1000mb group as 00/// ///// ///// when pressure is less than 950mbs.
• Identifier: T1T1T1D1D1 – Same temperature/dew point encoding procedures apply to all levels
• Identifier: d1d1f1f1f1 – Same wind encoding procedures apply to all levels
DATA FOR TROPOPAUSE LEVELS: 88PnPnPn TnTnTnDnDn dndnfnfnfn
• Identifier: 88 – Indicator for Tropopause level follows
• Identifier: PnPnPn – Pressure at the tropopause level reported in whole millibars. Report 88PnPnPn as 88999 when tropopause is not observed
• Identifier: TnTnTnDnDn – Same temperature/dew point encoding procedures apply
• Identifier: dndnfnfnfn - Same wind encoding procedures apply
MAXIMUM WIND DATA: 77PnPnPn dndnfnfnfn 4vbvbvava
• Identifier: 77 – Indicator that data for maximum wind level and for vertical wind shear follow when max wind does not coincide at flight. If maximum wind level coincides with flight level encode 66
• Identifier: PnPnPn – Pressure at maximum wind level in whole millibars
• Identifier: dndnfnfnfn – Same wind encoding procedures apply
• Identifier: 4 – Data for vertical wind shear follow
• Identifier: vbvb – Absolute value of vector difference between max wind and wind 3000 feet BELOW the level of max wind, reported to the nearest knot. Use "//" if missing and a 4 is reported. A vector difference of 99 knots or more is reported with the code figure "99".
• Identifier: vava – Absolute value of vector difference between max wind and wind 3000 feet ABOVE the level of max wind, reported to the nearest knot. Use "//" if missing and a 4 is reported. A vector difference of 99 knots or more is reported with the code figure "99".
AIRCRAFT AND MISSION IDENTIFICATION: 61616 AFXXX XXXXX XXXXX OB X KXXX
• Identifier: 61616 – Aircraft and mission identification data follows
• Identifier: AFXXX XXXX XXXXX: Mission ID
• Identifier: OB 04 – The observation number as transmitted from the aircraft.
NATIONALLY DEVELOPED CODES: 62626
• Identifier: 62626 – This is the remarks section. Only the remarks: EYE EYEWALL XXX (eyewall will be followed by the radian to the eye center procured from the ARWO), or RAINBAND, if release was made in a feeder band. The splash location will be recorded automatically by computer. Followed by last wind height in meters and the mean boundary layer wind with degrees to the nearest five-degree and knots.
PART BRAVO (B)
• XXBB – Identifier for a temp drop code
• The following 6 groups same as in PART ALPHA: Date/Time and location and SLP
SIGNIFICANT ISOBARIC LEVELS: nonoPoPoPo ToToToDoDo
• Identifier: nono – Number of level starting with surface level. Only surface will be numbered as "00". When a standard level is also selected as significant, repeat the level.
• Identifier: PoPoPo – Pressure at specified levels in whole millibars.
• Identifier: ToToToDoDo – Same temperature/dew point encoding applies.
SIGNIFICANT WIND LEVELS: 21212 nnPPP ddfff
• Identifier: nono – Number of level starting with surface level. Only surface will be numbered as "00". When a standard level is also selected as significant, repeat the level.
• Identifier: d1d1f1f1f1 – Same wind encoding procedures apply to all levels
SOUNDING SYSTEM INDICATION, RADIOSONDE/SYSTEM STATUS, LAUNCH TIME: 31313 srrarasasa 8GGgg
ADDITIONAL DATA GROUPS: 51515 101XX 0PnPnPnPn
• Identifier: 51515 – Additional data in regional code follow
• Identifier: 10166 – Geopotential data are doubtful between the following levels 0PnPnPnPn.
• Identifier: 10167 – Temperature data are doubtful between the following levels 0PnPnPnPn.
• Identifier: 10190 – Extrapolated altitude data follows:
a. When the sounding begins within 25mbs below a standard surface, the height of the surface is reported in the format 10190 PnPnhnhnhn. The temperature group is not reported
b. When the sounding does not reach surface, but terminates within 25mbs of a standard surface, the height of the standard surface is reported in Part A of the code in standard format and also at the end of Part A and Part B of the code in the format as 10190 PnPnhnhnhn.
• Identifier: 10191 – Extrapolated surface pressure preceds. Extrapolated surface pressure is only reported when the termination occurs between 850mbs and the surface. Surface pressure is reported in Part A as 99PoPoPo ///// and in Part B as 00PoPoPo /////. When surface pressure is extrapolated the 10191 group is the last additional data group reported in Part B.
61616, 62626 – Same procedures as Part A

I hope that helps

Shannon :)

Shannon thanks for your willingness to share with us your "on the scene" knowledge.

I have created a web based dropsonde decoder that is in beta testing:
http://tropicalatlantic.com/recon/
If anyone finds any problems with it let me know. I have an experimental option available that allows you to graph some of the data.

Holy cow! Awesome! Great work!

Thanks. Your post helped quite a bit in trying to figure it out. It finally motivated me to quit putting off creating one.

you are probably wondering....

Do we have sondes that have problem sondes?

yes, we do have problem sondes... missing data, late data etc.

As you can see, if a storm is stronger than 925mb we will be missing the 925mb reading. In the cause of Wilma we were missing the 1000mb reading because Wilma was, well... we all know how strong Wilma was.
If we have a bad sonde, we quickly launch another sonde to cover the bad sonde launch.

Some may have seen these changes already... but here they are...

000
UZNT13 KNHC 290001
XXAA 79004 99286 70883 08188 99017 26044 07012 00150 24636 07512
92829 20059 10514 85551 13632 10009 70177 09495 09008 50589 05991
20503 40759 18773 22503 88999 77999
31313 09608 82348
61616 AF308 WXWXA 08052822308 OB 05
62626 SPL 2858N08831W 2358 MBL WND 07511 AEV 00000 DLM WND 10006
016396 WL150 07012 078 =
XXBB 79008 99286 70883 08188 00017 26044 11950 20409 22920 19660
33850 13632 44827 12441 55822 12857 66814 14072 77800 14685 88666
08098 99516 04399 11406 16973 22392 21173
21212 00017 07012 11955 08011 22929 10514 33903 10015 44850 10009
55763 08510 66748 07013 77739 08010 88392 27502
31313 09608 82348
61616 AF308 WXWXA 08052822308 OB 05
62626 SPL 2858N08831W 2358 MBL WND 07511 AEV 00000 DLM WND 10006
016396 WL150 07012 078 =

BOLD area only..... here is the change....

instead of AF308 WXWXA TRAIN it now reads AF308 WXWXA 08052822308. 2008/05/28/2200GMT/AF308

the software upgrades have been pushed through our computers hence the reason for the change.

if a storm report comes up it would read AF308 (MISSION ID and STORM NAME) then 08052822308 (change for date/time)

What is the format of the longer mission identifier in some missions?

The "080611231419307" in the message below:

000
UZNT13 KNHC 120048
XXAA 62004 99283 70892 08189 99014 27647 15012 00126 26643 16012
92810 21444 ///// 85538 16835 ///// 70169 07656 09002 50587 07561
21502 40757 17365 01503 88999 77999
31313 09608 80020
61616 AF307 WXWXA 080611231419307 OB 04
62626 SPL 2833N08923W 0029 AEV 00000 DLM WND 19003 014401 WL150 1
5512 080 =
XXBB 62008 99283 70892 08189 00014 27647 11956 22820 22927 21445
33850 16835 44736 10256 55689 06432 66648 03642 77635 03059 88626
02236 99613 01860 11579 00550 22543 03360 33520 05557 44513 06365
55503 07358 66496 07766 77483 09142 88461 10774 99405 16167 11392
19163
21212 00014 15012 11010 16012 22979 15512 33745 12503 44392 00000
31313 09608 80020
61616 AF307 WXWXA 080611231419307 OB 04
62626 SPL 2833N08923W 0029 AEV 00000 DLM WND 19003 014401 WL150 1
5512 080 =
;

From:
http://www.nhc.noaa.gov/archive/recon/2 ... 120048.txt

Mission Identifier: 080611231419307

08 - Year
06 - Month
11 - Day
23 - ?
14 - ?
19 - ?
307 - Aircraft

What are those other numbers? Hour, minute, second? And if so, the time of what?

And in regards to the identifier you posted: 08052822308

That hour, 22GMT, is the time the equipment is first turned on for the mission? (Meaning it could be the take off time, but if you start recording messages a few hours after take off, then it would not be the take off time.) Or does it mark something else?

the 23z marks the time that the ARWO starts the mission. Typical missions start just while we are taxing. 2314 is the start of the mission.... I'm wondering if the ARWO pallet picked up the exact time of launch from the drop computer... only the drop computer records seconds... the arwo computer doesn't.... I'm wondering if the drop didn't correctly change the date when he/she powered up.

I will check.

[quote="Chris_in_Tampa"]What is the format of the longer mission identifier in some missions?

The "080611231419307" in the message below:

000
UZNT13 KNHC 120048
XXAA 62004 99283 70892 08189 99014 27647 15012 00126 26643 16012
92810 21444 ///// 85538 16835 ///// 70169 07656 09002 50587 07561
21502 40757 17365 01503 88999 77999
31313 09608 80020
61616 AF307 WXWXA 080611231419307 OB 04
62626 SPL 2833N08923W 0029 AEV 00000 DLM WND 19003 014401 WL150 1
5512 080 =
XXBB 62008 99283 70892 08189 00014 27647 11956 22820 22927 21445
33850 16835 44736 10256 55689 06432 66648 03642 77635 03059 88626
02236 99613 01860 11579 00550 22543 03360 33520 05557 44513 06365
55503 07358 66496 07766 77483 09142 88461 10774 99405 16167 11392
19163
21212 00014 15012 11010 16012 22979 15512 33745 12503 44392 00000
31313 09608 80020
61616 AF307 WXWXA 080611231419307 OB 04
62626 SPL 2833N08923W 0029 AEV 00000 DLM WND 19003 014401 WL150 1
5512 080 =
;

From:
http://www.nhc.noaa.gov/archive/recon/2 ... 120048.txt

Mission Identifier: 080611231419307

08 - Year
06 - Month
11 - Day
23 - ?
14 - ?
19 - ?
307 - Aircraft

What are those other numbers? Hour, minute, second? And if so, the time of what?

And in regards to the identifier you posted: 08052822308

That hour, 22GMT, is the time the equipment is first turned on for the mission? (Meaning it could be the take off time, but if you start recording messages a few hours after take off, then it would not be the take off time.) Or does it mark something else?[/quote]

1) chris, I checked on this topic... because of the software upgrade, the 231419 is the EXACT time mission was started... the drop occurred at 0020, 0029 channel stopped and the drop was read at 0048 (we stop the channel once the sonde gets into the water).... it only makes logical sense that 231419 is when the arwo started the mission. I'm doing the math and it should have been around 10-12 minutes to reach the ground from 400mb... somehow this sonde sat in water for 10 minutes before anyone realized to work it up.

2) the 22z is was when the arwo STARTED the mission... they round to the nearest whole hour (old software).... with the new software upgrade it is the exact time. 99% of time the mission is started during taxi....

Chris... in the previous post the drop was launched at 0020 and the sonde splashed at 0029... this report was sent at 0048..... this was dropped with the new software but the gremlins made a visit to this aircraft (read below)

we had this problem the other day... each time we opened the temp code to look at the drop report a 'new time' was put in where 0048 is... We found several glitches in the software and are working on fixing the problems.

Thanks for the info. I thought it might be the exact time but wanted to make sure. And thanks for the clarification on the mission start time.

You are awesome :uarrow: