The solar activity most significantly affect space weather state including solar wind parameters, sudden change in the ionization level in the ionosphere, solar energetic particle (SEP) events and geomagnetic storms. In this poster we will present the ground-based measurements in the ultra- and extremely low-frequency magnetic waves (ULF/ELF, range from 0.03 to 55 Hz) recorded by the ELF Hylaty station located in Bieszczady Mountains (SE Poland) by last 15 years. The dynamic power spectrum (DPS, time-frequency domain) calculated in the frequency range (0.03-5 Hz) were the main tool to detect magnetic pulsations (Pc1). The DPS were used for detect and monitoring magnetic pulsation connected with geomagnetic storms reported by disturbance of storm time index (Dst). We investigate threshold when the Pc1 pulsation could be observed at the ELF Hylaty station (L-shell ~ 2).