This work is aimed to study the spatial distribution of the magnetic field components variations during substorms, when the central substorm meridian is located near the magnetic stations. Only in this case the typical for substorm changes in the signs of the magnetic components could be observed in the spatial structure. In this purpose, an isolated substorm, the substorm on 22 March 2013 at ~23:10 UT, with central meridian over Europe has been chosen. Magnetic field data from INTERMAGNET, SuperMAG and IMAGE databases have been used. The X and Y variations due to the substorm were computed for more than 40 stations based on the developed programs. Maps of the spatial distribution of the magnetic variations have been created, longitudinal and latitudinal profiles for this event have been constructed for the time of the midlatitude positive bay (MPB) maximum at Panagjurishte (PAG) and some other moments of the substorm development. Some characteristics as the line of sign conversion latitude, the central meridian, the longitudinal and latitudinal extent of the positive bays and the latitudinal and longitudinal dependence of the variations have been estimated. A local MPB index was computed for the European region, which provide information about the substorm appearance at midlatitudes from substorms, developed over Europe.