This work reports evidence for correlated directional anisotropy in low-to-intermediate redshift cosmological observations. Using Type Ia supernovae from the Pantheon+ compilation and baryon acoustic oscillation measurements from DESI, a consistent preferred expansion axis is identified near Galactic coordinates (l, b) ≈ (200°, –70°), close to the CMB Cold Spot. A dipole-modulated residual analysis reveals enhanced expansion along this direction, supported independently by both probes. Robustness checks include a full-sky directional scan, bootstrap resampling with 10,000 iterations, and jackknife removal across sky sectors. The signal persists under standard systematic tests, indicating it is unlikely to result from survey geometry or calibration effects. The results suggest a modest deviation from statistical isotropy at ~3σ significance, with possible connections to large-scale structure, bulk flows, or superhorizon perturbations. This preprint is submitted to MNRAS. Extended diagnostic outputs and intermediate sky maps are archived by the author and may be shared with qualified researchers upon reasonable request. Clarification: The −3.53 value shown for the SN dipole amplitude reflects internal fit scaling units.The physically relevant amplitude is ~0.03–0.04 mag, i.e. 1–2% distance modulation, fully consistent with bulk-flow expectations. Direction and significance are unaffected. This version clarifies the reporting units for the supernova dipole amplitude (now stated in physical magnitudes, Δm ≈ 0.035 ± 0.009 mag), explains the distinction between our distance-dipole estimator and DESI clustering-anisotropy analyses, and adds a calibration appendix stub. No numerical results were changed. Code release is scheduled for referee stage. Update — 3 November 2025 A revised version of this analysis has been submitted to Monthly Notices of the Royal Astronomical Society (MNRAS). This Zenodo upload reflects the pre-submission version of the manuscript and analysis description.Edits made since include clarifications of systematics, language updates (e.g., “evidence for” instead of “detection”), and the addition of a peculiar-velocity cross-talk discussion. Code will be uploaded at the “first-look” stage once the manuscript enters peer review, per journal policy. The scientific result and core methodology remain unchanged. Update — January 2026 The revised manuscript submitted to Monthly Notices of the Royal Astronomical Society (MNRAS) under reference MN-25-2588-MJ.R1 was returned after editorial screening as out of scope for the journal, and was not sent for external peer review. No technical, methodological, or statistical objections were raised in the editorial decision. This Zenodo record therefore serves as the public archival release of the analysis, preserving the full methodology, results, and revision history. The author makes the work available for independent scrutiny, reuse, and comparison with related studies of large-scale cosmological anisotropy. This research is produced independently under the Drive-In s.r.o. research programme.Readers who wish to support its continuation may do so here: https://ko-fi.com/johnryder99892

Evidence of a preferred expansion direction in low-redshift cosmology from correlated anisotropy in Pantheon+ supernovae and DESI BAO data, supported by bootstrap and jackknife stability tests.