Enhance TC-Pairs consensus logic to compute the spread of the location, wind speed, and pressure.

[JohnHalleyGotway]

Describe the Enhancement

This enhancement request initially arose via METplus discussions in dtcenter/METplus#1341.

The METplus team met with NOAA/EMC on 2/2/2022 to discuss this issue and this GitHub issue is the result. Here are the steps:

• Enhance the consensus derivation logic in TC-Pairs to also compute the location spread and standard deviation of the wind speed and pressure values.
  • Compute the location spread as the mean of the great circle distance from the consensus location to the location of each of the members.
  • Compute the standard deviation of wind speeds and pressure values as you normally would.
• After these are computed, need to decide where/how to write these 3 additional values to the output.
  • One option to consider is adding 3 new columns to the end of the existing TCMPR line type. That wouldn't require many changes to the TC-Stat and the METdatadb load logic updates would be pretty easy. One downside is that the mean location and location spread would be very far from eachother in the output line. And that solution may conflict with the solution for Enhance TC-Pairs to read hurricane model diagnostic files (e.g. SHIPS) and TC-Stat to filter the new data #392.
  • Another option to consider is defining a new version of the TCMPR line type (perhaps "TCMPRCON" or something?) that is the same as the existing TCMPR line type, but with 3 extra columns added internally (not at the end). After the average location, speed, and pressure, we'd report the corresponding spread values. The downside is extra documentation and testing, upgrading TC-Stat to handle this, and upgrading METdata/METviewer to handle it. You'd often want to visualize TCMPR data from constituent models on the same plot at the TCMPRCON data. That may be difficult if they're stored in different line types.

Please see attached slides from the 2/2/2022 meeting:
J.Peng_discussion_20220202_new.pdf

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27703542

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[JohnHalleyGotway]

Mentioned in the gap analysis for EVS version 1.0 on 9/7/22.
@JiayiPeng-NOAA should be added as an assignee on this issue.

[JohnHalleyGotway]

Received feedback from @JiayiPeng-NOAA on 11/14/2022 recommending that we rename the 5 new TCMPR output columns as follows. Note that I swapped the order of TRACK_SPREAD and TRACK_STDEV below to group all the STDEV columns together:

NUM_MEMBERS, TRACK_SPREAD, TRACK_STDEV, MSLP_STDEV, MAX_WIND_STDEV

I confirmed and approved these changes with @KathrynNewman.

Reopening this issue to handle this renaming.