Experimental wind and circular-radius diagnostics
The frozen 1.2 weights and neural architecture are unchanged. Maximum wind is
the existing learned auxiliary vmax output, in knots, not a resolved wind map.
Its averaging period is not harmonized to JMA, and skill has not been established
by the route/pressure benchmark. Do not treat this product as operational advice.
wind_estimation.py optionally diagnoses each model-generated pressure member:
- Sample complete circular rings about that member's predicted centre, no more finely than the source/reconstruction grid, out to at most 480 km.
- Compute the azimuthal-mean radial pressure gradient (hPa converted to Pa).
- Solve
Vg^2/r + |f| Vg = (1/rho) dp/dr, with air density 1.15 kg/m3, then apply a fixed 0.8 ocean surface-reduction assumption. This is uncalibrated; motion, land friction, asymmetry, boundary-layer jets and averaging periods are not represented. No future observations or official routes are inputs. - Report a resolved gradient-wind peak/RMW and outward 34/50/64-kt crossings. These are circular equivalent radius estimates, not quadrant radii and not isobar radii. Coarse (>50 km) source grids, incomplete rings, unresolved peaks and missing crossings produce nulls, not invented zeros or edge radii.
- Diagnose members individually, then summarize. A mean is supplied only when every member has that estimate. Valid counts and p10/p90 describe spread; they are not calibrated confidence intervals. Never diagnose a mean map and call it a mean of 50 radius predictions.
The 20-km moving core is a learned reconstruction. A resampled 0.25-degree regional image does not add resolved observations. Even an available estimate therefore remains experimental. A single gridded basin mean cannot reconstruct the missing member diagnostics. Legacy forecasts without saved member/core outputs retain unavailable estimates instead of being rerun or relabelled.
For the saved 50-member regional composite, core origins were not archived. That release's core spans +/-640 km and centre association is restricted to 300 km about its origin. Consequently this read-only legacy exporter samples only rings within 300 km of each predicted centre, conservatively inside the core footprint; a missing crossing beyond that limit remains unavailable. New forecasts use the actual moving-core coordinates and their valid masks.
Defaults are fixed physical assumptions, not fitted to showcase outcomes. Before claiming skill, freeze eligible whole-storm held-out cases; score +6 to +120 h maximum winds and agency-compatible wind radii separately, with coverage, unresolved cases, land/ocean breakdowns and whole-storm uncertainty. No such validation or calibration is claimed by this implementation.
References: NOAA PaHM theory and limitations and Chavas, Reed and Knaff (2017).