by R. Gil Student
Since we recently experienced a significant snowfall, it is worthwhile to review some of the ideas of snow removal on Shabbos. First and foremost, people need to be careful. If you have trouble walking, do not go outside if you think you might fall.
One issue is whether snow is muktzah, something which may not be moved directly. Ostensibly, this is a simple matter because it is discussed by early authorities. Generally, you may not use something which comes into existence on Shabbos. It is considered nolad, as if it is newly born or created, and is a subcategory of muktzah. However, the Gemara (Eruvin 46a; cf. Tosafos, Beitzah 2a s.v. ka) says that rain is not considered nolad because the moisture was in the air long before the rain fell — therefore you can use rainwater that falls on Shabbos. Evidently, this would also apply to snow, which is how most authorities seem to rule (cf. Rav Moshe Stern, Be’er Moshe 1:20; Rav Yehoshua Neuwirth, Shemiras Shabbos Ke-Hilchasah, ch. 16 n. 110).
However, in a characteristically bold but sensible ruling, Rav Moshe Feinstein (quoted in The Halachos of Muktza, p. 165 n. 10) said that snow is muktzah for a different reason. Since we do not normally use snow for anything and it is not food for animals, snow is muktzah like stones and sticks even if it fell before Shabbos.
In 1957, there was a snow storm in Jerusalem on Shabbos and people asked Rav Tzvi Pesach Frank whether they were allowed to clean the snow off their roofs (Har Tzvi, Tal Oros, soseir no. 1). One issue he raised is whether the snow has hardened or not. If it has hardened, it seems that since it has become attached to the ground it is considered part of the ground. Therefore, removing it would be similar to digging something out of the ground, which is prohibited on Shabbos. However, if it is soft snow then you are allowed to move it.
Rav. Dovid Ribiat (The 39 Melachos, p. 1098) also points out that this discussion is only on a hard surface like a roof, sidewalk or driveway. You may not shovel even soft snow that is on dirt because doing so is considered smoothing out the surface, which is forbidden.
Rav Ribiat (endnote 147d) quotes Rav Avraham Weinfeld (Responsa Lev Avraham, no. 49) as ruling that shoveling snow is a problem of exertion on Shabbos. The Mishnah (Shabbos 126b) prohibits moving large objects on Shabbos because of the exertion. The only permission is to do it for a mitzvah. Similarly, reasons the Lev Avraham, shoveling would be prohibited unless it is to clear a path for people to walk to shul or to remove danger.
Rav Asher Bush (“Tipul Be-Sheleg Ve-Kerach Be-Shabbos” in Beis Yitzchak (no. 40, 2008)) questions whether we can permit shoveling on Shabbos in order to clear a path for the public. The Pri Megadim (Orach Chaim, 333, MZ 1) says that we cannot compare one act to another, in order to infer permission. Generally, we only permit something that is doubly rabbinic (shevus di-shvus) for a mitzvah. It is a unique exception to permit a single rabbinic prohibition for a mitzvah. Therefore, Rav Bush only permits asking a Gentile to shovel on Shabbos in order to clear a path for the public to go to shul.
The above assumes that there is an eruv, and therefore there is no problem of carrying and/or moving the snow. What if there is no eruv? Rav Menasheh Klein (Mishneh Halachos vol. 5 no. 4) discusses whether, in a place where carrying is only rabbinically prohibited, you can shovel snow to prevent people from falling. He is hesitant to permit it because people often walk on snow so it is difficult to determine when it is truly dangerous. He concludes that you may hire a Gentile to do it for you. Note that his assumption about where there is a biblical or rabbinic prohibition to carry is the subject of a large debate.
V. Snow Blowers
Rav Asher Bush (ibid.) adds that the permission to have a Gentile shovel snow for you on Shabbos only applies to actual shoveling, when it is rabbinically forbidden. If he uses a snow blower, he is committing a biblical prohibition on your behalf publicly, on your property (in front of your house) and with your permission. However, if the shul needs a Gentile to remove snow from in front of the shul and can only find someone who will use a snow blower, this might be permitted. If this is the only way to prevent shul from being cancelled, it become a need for a public mitzvah for which some permit asking a Gentile to do a biblically forbidden labor.