Yes, it is. In fact, it is significantly easier to find an Ambrosian Rite Mass than a Mozarabic one. Here’s some more information from Wikipedia:
Ambrosian Rite (also sometimes called the Milanese Rite) named after Saint Ambrose, bishop of Milan in the fourth century, is a Catholic liturgical rite practised among Catholics in the greater part of the Archdiocese of Milan (excluding, notably, the city of Monza, and a few other towns), and neighbouring area, including some five million Catholics in Lombardy, Italy, and in about fifty parishes of the Diocese of Lugano, in the Canton Ticino, Switzerland.
It is distinguished from the Roman Rite by particular features in some parts of the liturgical year that have different durations: Advent is of six weeks instead of four, and there is no Ash Wednesday, as Lent starts on Sunday, so the Ambrosian Carnival ends four days later, on “sabato grasso” (Italian for fat Saturday), the equivalent of Shrove Tuesday or “mardi gras” (French for fat Tuesday) in the folk practices of the Roman Rite. The Liturgy of the Hours (Divine Office or Breviary) and the prayers and ceremonies of some of the Sacraments are different in structure and various features, as is the Mass. The music associated with these services is Ambrosian chant.
Although at various points in its history the distinctive Ambrosian Rite has risked suppression, it survived after the Second Vatican Council partly because the then Pope, Paul VI was sympathetic, having been the Archbishop of Milan. In the 20th century it also gained prominence and prestige from the attentions of two other scholarly Archbishops of Milan: Achille Ratti, later Pope Pius XI, and the Blessed Ildefonso Schuster, both of whom had been involved in studies and publications on the rite before their appointment.