Tropical cyclone tracks, wind radii and vortex
Closed this issue · 19 comments
Initial request
With the reference to the (https://meetings.wmo.int/INFCOM-3/_layouts/15/WopiFrame.aspx?sourcedoc=%7B964360a3-5884-4443-8c5b-b8b6ebca9b12%7D&action=view&wdAccPdf=0&wdparaid=6AED0856)
TT-TCPara have requested a new BUFR template for tropical cyclone to include new vortex variables.
Amendment details
1. Add a new element in table B
| F X Y | ELEMENT NAME | UNIT | SCALE | REFERENCE VALUE | DATA WITH (bits) |
|---|---|---|---|---|---|
| 0-01-130 | Storm identifier (long) | CCITT IA5 | 0 | 0 | 32 |
2. Add a new elements in table B
| F X Y | ELEMENT NAME | UNIT | SCALE | REFERENCE VALUE | DATA WITH (bits) |
|---|---|---|---|---|---|
| 0-11-024 | Average u component after the vortex removal | m/s | 1 | -4096 | 13 |
| 0-11-025 | Average v component after the vortex removal | m/s | 1 | -4096 | 13 |
3. Add a new table B descriptor 0-08-055 for Method used to calculate the average wind components after removing vortex
| F X Y | ELEMENT NAME | UNIT | SCALE | REFERENCE VALUE | DATA WITH (bits) |
|---|---|---|---|---|---|
| 0-08-055 | Method used to calculate the average wind components after removing vortex | Code table | 0 | 0 | 4 |
4. Add a new CODE/FLAG TABLE 0-08-055 for Method used to calculate the average wind components after removing vortex
| Code | Method used to calculate the average wind components after removing vortex |
|---|---|
| 0 | Calculate the area average of the u and v components at pressure levels from 0 to 500km centred on the surface vortex position |
| 1 | Calculate the area average of the u and v components at pressure levels from 0 to radius greater than 500km centred on the surface vortex position |
| 2-14 | Reserved |
| 15 | Missing value |
NOTE: Method used to calculate average wind components after removing vortex is described in Knaff et al. (2009)
5. Add a new template in table D
| Table Reference F X Y | F X Y | ELEMENT NAME | DESCRIPTION |
|---|---|---|---|
| (Tropical cyclone track, wind radii and vortex ) | |||
| 3 16 083 | 0 01 033 | Identification of Originating/generating Centre | |
| 0 01 034 | Identification of Originating/generating Centre Sub-Centre | ||
| 0 01 032 | Generating application | ||
| 0 01 130 | Storm identifier (long) | ||
| 0 01 027 | WMO long storm name | ||
| 0 01 030 | Numerical model identifier | ||
| 0 01 090 | Technique for making up initial perturbations | ||
| 0 01 091 | Ensemble member number | ||
| 0 01 092 | Type of ensemble forecast | ||
| 3 01 011 | Year, month, day | ||
| 3 01 012 | Hour, minute | ||
| 0 08 005 | Meteorological attribute significance | ||
| 3 01 023 | Latitude/longitude (coarse accuracy) | ||
| 0 08 005 | Meteorological attribute significance | ||
| 3 01 023 | Latitude/longitude (coarse accuracy) | ||
| 0 10 051 | Pressure reduced to mean sea level | ||
| 0 08 005 | Meteorological attribute significance | ||
| 3 01 023 | Latitude/longitude (coarse accuracy) | ||
| 0 11 012 | Wind speed at 10 m | ||
| 1 07 004 | Replicate 7 descriptors 4 times | ||
| 0 19 003 | Wind speed treshhold | ||
| 1 05 004 | Replicate 5 descriptors 4 times | ||
| 0 05 021 | Bearing or azimuth | ||
| 0 05 021 | Bearing or azimuth | ||
| 2 01 131 | Change data width | ||
| 0 19 004 | Effective radius with respect to wind speeds above threshold | ||
| 2 01 000 | Change data width | Set to missing (cancel) | |
| 1 16 000 | Delayed replication of 16 descriptors | ||
| 0 31 001 | Delayed descriptor replication factor | ||
| 0 08 021 | Time significance | ||
| 0 04 024 | Time period or displacement | ||
| 0 08 005 | Meteorological attribute significance | ||
| 3 01 023 | Latitude/longitude (coarse accuracy) | ||
| 0 10 051 | Pressure reduced to mean sea level | ||
| 0 08 005 | Meteorological attribute significance | ||
| 3 01 023 | Latitude/longitude (coarse accuracy) | ||
| 0 11 012 | Wind speed at 10 m | ||
| 1 07 004 | Replicate 7 descriptors 4 times | ||
| 0 19 003 | Wind speed threshold | ||
| 1 05 004 | Replicate 5 descriptors 4 times | ||
| 0 05 021 | Bearing or azimuth | ||
| 0 05 021 | Bearing or azimuth | ||
| 2 01 131 | Change data width | ||
| 0 19 004 | Effective radius with respect to wind speeds above threshold | ||
| 2 01 000 | Change data width | Set to missing (cancel) | |
| 1 04 000 | Delayed replication of 4 descriptors | ||
| 0 31 001 | Delayed descriptor replication factor | ||
| 0 08 055 | Method used to calculate the average wind components after removing vortex | ||
| 0 07 004 | Pressure | ||
| 0 11 024 | Average u component after the vortex removal | ||
| 0 11 025 | Average v component after the vortex removal |
Comments
No response
Requestor(s)
TT-TCPara
Marijana Crepulja (ECMWF)
Fernando Prates (ECMWF)
Stakeholder(s)
WMO member states
Publication(s)
Example: Manual on Codes (WMO-No. 306), Volume I.2, BUFR code table 0 20 009
Expected impact of change
MEDIUM
Collaborators
ECMWF
References
No response
Validation
No response
https://github.com/wmo-im/CCT/wiki/Teleconference.16.May.2024 notes:
Marijana introduced the proposal; Jeff suggested using the storm identifier and making it longer with a 208 operator; Anna noted that their description for the storm identifier for cyclones differs from the note 1 in Table B.
@marijanacrepulja will follow up with TT-TCPara regarding their requirements for the storm identifier.
@amilan17 follow up with WMO colleagues.
@marijanacrepulja add table to list methods used to calculate wind
WIPPS Guide states: "The storm identifier is a 4-character string, with the first 3 characters being numbers and the last being a capital letter."
MoC note states: "The storm identifier (descriptor 0 01 025) has the following meaning: the first two characters shall be a numeric sequence number assigned by the originator of the message; the third character is a letter indicating the ocean basin..."
https://github.com/wmo-im/CCT/wiki/Teleconference.2024.June.4and5 notes:
Marijana made some updates to the proposal; discussion about whether to add a new "storm identifier" for cylones vs extending the existing storm identifier with an extension and revision to the note;
ACTION
@amilan17 @marijanacrepulja ask colleagues: what regulations are behind the cyclone identifier? Can the identifier be split into two parts (numeric+basin)?
@shirley-xuelei will validate when ready
@marijanacrepulja should there also be a note added to 3 16 082 to indicate that this new template should be used instead?
I spoke with my colleauge in the Secretariat who is supporting that team and she said: "TCPara decided to expand to four characters to take in pre-genesis phase of cyclone tracks .... to distinguish the existing analysis position (001-099) and new analysis position from the RSMC (100-999)"
I spoke with my colleague who is a member of TCPara and he explained that
In case of tropical depression e.g. using 3 characters for identification
Storm identifier = 0ZW
Storm name = 0ZW
Splitting Storm identifier into two parts, numerical and letter would not be necessary as the storm identifier is used as a whole. Additionally the range up to 999 numbers is sufficient.
Therefore, one new descriptor for Storm identifier is preferred.
https://github.com/wmo-im/CCT/wiki/Teleconference.24and26.June.2024 notes:
Rename new code to "storm identifier (long)"; Marijana will update the branch and prepare sample data
@shirley-xuelei please find attched zip file that contain sample BUFR file and txt file as output of decoding. Hope you will be able to validate the data. Many thanks.
I have updated the branch.
https://github.com/wmo-im/CCT/wiki/Teleconference.2.July.2024 notes
@shirley-xuelei and @sergioh-pessoal to validate the samples
@shirley-xuelei please find attched zip file that contain sample BUFR file and txt file as output of decoding. Hope you will be able to validate the data. Many thanks.
I have updated the branch.
@marijanacrepulja @amilan17 The data was validated, and please find the decoded file attached. I randomly checked some element values and didn't find any problems, and there are two suggestions for #201 for your reference.
- The unit of 0-08-055 should be 'Code table', other than 'Numeric'.
- The element name of '1 07 003' and '1 05 004' is not supposed to be 'Delayed replication of x descriptors'.
tropical_cyclone_vortex_dec.zip
@marijanacrepulja please let me know when you've updated the branch per Lei's review. thx.
Two questions, if I'm allowed to make:
- Really trivial: did you intend "threshold" for the element name of 0 19 003 "Wind speed treshhold" ?
- Number of wind speed thresholds: did you intend to put 0 19 004 in place of 0 19 003 ?
Approved amendment to the WIPPS Manual, EC-78/Doc.4.1.2(6) reads "Quadrant radii of sustained 10 m-winds of 28/34/50/64 kt". We are supposed to provide radii for four (not three) thresholds, if I'm taking right.
@etoyoda Thank you very much for your valuable comments.
We intended "threshold" for the element name of 0 19 003 "Wind speed treshhold".
I have updated the BUFR template to allow reporting for four thresholds. Please see
| 1 07 004 | Replicate 7 descriptors 4 times | |
|---|---|---|
| 0 19 003 | Wind speed threshold | |
| 1 05 004 | Delayed replication of 5 descriptors | |
| 0 05 021 | Bearing or azimuth | |
| 0 05 021 | Bearing or azimuth | |
| 2 01 131 | Change data width | |
| 0 19 004 | Effective radius with respect to wind speeds above threshold | |
| 2 01 000 | Change data width |
New samples, to allow reporting for four thresholds as defined in WIPPS Manual, EC-78/Doc.4.1.2(6) reads "Quadrant radii of sustained 10 m-winds of 28/34/50/64 kt"
@shirley-xuelei Thank you very much for validating the samples and your valuable comments. I have updated branch/proposal accordingly.
@etoyoda has made a valuable comment that we should report for four thresholds as defined in WIPPS Manual.
I have updated a proposal/branch and provided new samples.
@marijanacrepulja
I’ve decoded the sample successfully with MBUFRTOOLS, and compare the results with text provided. The results are equivalent, and have same values for all variables.
So the template is valid
Please, find attached the decoded text file
tropical_cyclone_vortex_latest.decoded.txt.gz
@sergioh-pessoal Many thanks for your valuable and prompt help with validation!
tropical_cyclone_vortex_latest_dec.zip
@marijanacrepulja I also validated the new template using our software , and it is valid. Please find the decoded file attached.
@shirley-xuelei Thank you very much for your valuable support with validation. I really appreciate it.