Closed marqh closed 4 years ago
The following are issues brought up after the publishing of 3.0.0RC3:
(1), (2) and (3) involve a change of the corresponding TAC template or selected de-synchronization of IWXXM with the TAC template. Having said that, we may still want to give some guidance for (1) to get around of the issues temporarily.
The following are proposed addition to TAC-to-XML-Guidance.txt:
==========================
TAF
==========================
...
Maximum and minimum temperature forecasts - TXnn/nnnnZ TNnn/nnnnZ
As indicated in Annex 3 these shall be given in pairs. If more than one pair of
temperatures are provided and only one maximum or minimum is anticipated one may
consider repeating this in both groups.
Comments and also suggestions to (2) are most welcomed
Choy,
While I agree that these are issues that need resolution, I was more focused on resolving the ambiguity of certain situations, namely, missing RVR in METARs/SPECIs when Annex 3 demands RVR be reported, and how stationary phenomenon is depicted in AIRMET/SIGMET products.
For (2), may I suggest the following: if any mandatory item(s) in the iwxxm:TropicalCycloneForecastCondition element is (are) not provided, then the parent element 'iwxxm:forecast' nilReason shall be set to 'http://codes.wmo.int/common/nil/nothingOfOperationalSignificance'.
For (2), may I suggest the following: if any mandatory item(s) in the iwxxm:TropicalCycloneForecastCondition element is (are) not provided, then the parent element 'iwxxm:forecast' nilReason shall be set to 'http://codes.wmo.int/common/nil/nothingOfOperationalSignificance'.
I am not too sure whether you can have something in TAC but nil in IWXXM. How often does this happen?
That is what the MIE paper is about, yes? Tokyo and Miami sometimes issue TCAs which cannot be implemented in IWXXM because Annex 3 does not address the weakening or dissipation of TCs. I don't know how often this occurs (but obviously every TC dissipates). IIRC, there is a proposal for increased forecast length of TCAs, so this issue (TC dissipation) will occur more frequently in the product. Regardless of the TAC form, I think MIE needs to look at this and provide a solution.
I am thinking this the other way round. The regulations are there for us to comply with, and if we believe they are inappropriate we should change them instead of doing what we want. Based on the two examples you provided in #166, I have the following suggestions:
If this is something sensible then our action will be (i) to include in the guidance making iwxxm:forecast nil for dissipated TC forecasts, (ii) at MIE/6 urge TCACs to observe and conform to the TAC templates (which should automatically comply with IWXXM) in preparing TCAs, and (iii) seek their views with regard to the updating of the TAC templates as necessary.
I concur with your points.
The above was implemented in 3.0.0RC4.
https://github.com/wmo-im/iwxxm/blob/master/IWXXM/TAC-to-XML-Guidance.txt
for example:
169