Halacha Orach Chaim 230

A person can and should pray for success in all areas of life. However, one should not pray for something that is dependent on a miracle to occur. For example, if someone hears cries coming from within a city, a prayer that the cries should not be coming from ones family and home is considered a prayer in vain. The reason for this is because whatever happened already took place, and one should not pray for miracles.

It would be appropriate to pray that peace and harmony should prevail in one’s home at a time that there is no known danger. When returning home from a trip it is prudent to offer thanks on a safe return.
When engaging in business, one should pray that the business deal should be successful. One should not pray for success in a business engagement after the deal has begun. At that point one should give thanks for the success that has been had from the business deal.

Before going in for medical treatment one should pray that the treatment should be effective and successful. Upon the completion of a medical treatment one should thank Hashem for the success. According to the Taz, and perhaps the Bais Yosef, this Bracha can be said with the Shem Umalchus, however the Mishna Berura says that he has not seen this done.

Upon seeing a rainbow, one should recite the Bracha Zocher Habris Vneeman Babriso Vkayam Bmaamaro. The Mechaber writes that one should not stare at it.

In addition, the Mishna Berura writes that if someone sees a rainbow, he should not tell other, rather he should privately recite the proper Bracha. The reason for this is that a rainbow is a sign that Hashem in not satisfied with the world, and if not for the covenant that was made with Noach, the world would be in danger of destruction. By telling others, we are publicizing this bad omen.

There is no limit to the amount of times this Bracha can be recited.

The Mechaber teaches us the Halachos of Birchas Hachamah here as well. Birchas Hachamah takes place once every 28 years when the sun is in the exact location it was in at the time the world was created. This Mitzva was done this past Pesach.

Halacha Orach Chaim 228

When one sees wondrous mountains rivers or deserts, a Bracha of Oseh Maaseh Beraishis should be recited. These Brachos are only recited upon seeing a natural phenomenon that is uncommon. Reb Shlomo Zalman rules that someone who lives near one of these natural phenomena, and they have become commonplace for him, should not recite this Bracha.

Upon seeing The Yam Hagadol, one is to recite a Bracha of Oseh Yam Hagadol. There is a disagreement what exactly the Yam Hagadol is.

According to the Mechaber, the Bracha is recited on seeing the Mediterranean sea. According to other Poskim, the Bracha is recited upon seeing the great oceans that surround the world. Dayan Fisher follows this second opinion. However, he adds that when reciting the Bracha of Oseh Maaseh Beraishis on the Mediterranean sea, one should make a point of adding the phrase Oseh Yam Hagadol upon completion of the Bracha.

Orach Chaim 227

Reb Shlomo Zalman writes that one can recite a Bracha on lighting even if the bolt is not seen; but only the light is seen.

If the sky cleared up, and new clouds gathered to create more lighting and thunder, the Halacha is that a new Bracha should be recited. However, if the storm carried on from one day to the next, a new Bracha can be recited on the same storm the next day. A new day regarding this Halacha is morning, and not night time.

These Brachos can only be recited within three or four seconds. After a delay of this amount of time, a Bracha cannot be recited. The three or four seconds is the amount of time it takes someone to greet their Rebbe.

There is a discussion among the Poskim if this Bracha should be recited if one is in the middle of Birchas Hamazon. It would seem that one should not interrupt Birchas Hamazon to recite these Brachos. One may interrupt learning in order to recite these Brachos.