Refine PB2NC logic to reduce memory usage

[JohnHalleyGotway]

Describe the Enhancement

Issues running version 12.2.1 of the MET PB2NC tool operationally on WCOSS were observed in July 2026 and again in September 2026. The PB2NC jobs failed due to large memory consumption. The short term patch for this issue is to set the METplus PB2NC_OBS_WINDOW configuration option to define a smaller point observation retention time window. Retaining fewer observations consumes less memory and make the issue less like to recur with the current EVS configurations of METplus. However, a better longterm fix would improve PB2NC by reducing its memory consumption.

For this issue, recommend the following:

• Inspect the logs and sample data stored in seneca:/d1/projects/METplus/discussions/OMD_PB2NC_failure_202060909.
• As needed, refer to the EVS configurations found the NOAA-EMC/EVS repository.
• Analyze the PB2NC tool and look for opportunities to reduce it's memory consumption.
• Recommend running sample cases through a profiler to quantify improvements in memory consumption.
• Any code changes should not modify the output generated by PB2NC.

Time Estimate

Up to 3 days?

Sub-Issues

Consider breaking the enhancement down into sub-issues.

Relevant Deadlines

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Funding Source

FY27 NOAA DTC METplus funding

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Define Related Issue(s)

Consider the impact to the other METplus components.

• METplus, MET, METdataio, METviewer, METexpress, METcalcpy, METplotpy
• No impacts expected

Enhancement Checklist

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