Abstract We present conjugate observations of ionospheric small‐scale magnetic perturbations (dB) $(dB)$ and GPS scintillations from the Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites (TRACERS) and the Canadian High Arctic Ionospheric Network (CHAIN) during a storm‐time substorm on 9 August 2025 in the nightside auroral region. Rotational transverse dB $dB$ of up to ∼1,000 nT, associated with filamentary field‐aligned currents (FACs) exceeding 150 μA/m2 ${upmu }mathrm{A}/{mathrm{m} }^{2}$ on spatial scales of ∼1–16 km, were colocated with extreme, localized auroral scintillations (σϕ> ${sigma }{phi } > $ 10 rad, S4≃ ${S}{4}simeq $ 0.3) and ∼10 dB‐Hz intensity reduction. The most intense scintillations lasted ∼1.5 s and coincided with peaks in auroral electrojets, Pi2 pulsations, and enhanced dTEC (∼12 TECU). The sheet‐like morphology and spatiotemporal correlation with auroral electrojets suggest that Farley–Buneman processes likely play a dominant role in scintillation formation, with additional contributions from FAC‐driven and gradient‐drift instabilities.